David J. Magid, MD, MPH

To evaluate the health system cost of a home blood pressure monitoring (HBPM) program versus usual care in an integrated healthcare system.

This cost-effectiveness analysis was based upon a previously completed randomized controlled trial of 348 hypertensive patients, in which mean systolic blood pressure (BP) was lowered 21 versus 8 mm Hg in the HBPM and usual care groups, respectively, and BP control was achieved in 54% versus 35% of patients (

This analysis compared direct costs from the health plan perspective, including clinic visits, e-mail and telephone encounters, laboratory tests, medications, hospitalizations, and emergency department visits between the 2 groups. Primary outcomes were the incremental hypertension care-related cost of HBPM per mm Hg lowering of systolic BP per patient, per additional BP controlled, and per life-year gained.

Median hypertension-related cost per patient over 6 months was $455 in the HBPM group and $179 for usual care (P <.001). This increase was attributable to additional e-mail and telephone encounters, greater antihypertensive medication use, additional laboratory monitoring, and the BP monitor. Median total cost per patient was $1530 and $1283 for the HBPM and usual care groups, respectively (

 = .034). The HBPM program increased hypertension-related expenditures by $20.50 per mm Hg lowering of systolic BP, $1331 per additional patient achieving BP control at 6 months, and $3330 per life-year gained.

The HBPM program requires investment in outpatient encounters, medications, and laboratory monitoring, but produces significantly improved BP control.

This study highlights the cost-effective manner in which home-monitoring technology plus clinical pharmacy specialist involvement improves blood pressure (BP) control.

		Patients in the Home Blood Pressure Monitoring (HBPM) program had more overall telephone and email encounters with a pharmacist, but the same number of office visits with a pharmacist, and utilized more antihypertensive medications and laboratory monitoring compared with patients managed through usual care.

		The incremental 6-month cost of this intervention was $20.50 per mm Hg of systolic BP lowered, $1331 per additional BP controlled, and $3330 per life-year gained compared with usual care.

		The incremental costs of this intervention compare favorably with other interventions, largely because the HBPM program was more effective than usual care.

Nearly $51 billion in direct and indirect costs related to hypertension were spent in the United States in 2009, with much of it attributable to the healthrelated consequences of hypertension.

 One in 3 adults in the United States has hypertension, and about half of those have uncontrolled blood pressure (BP), putting them at increased risk for acute myocardial infarction, stroke, renal disease, and congestive heart failure.

 Lowering BP has been shown to reduce the occurrence of these events.

Despite effective therapeutic interventions to control BP, at least a quarter of patients with uncontrolled hypertension receive no pharmacologic treatment. Novel care delivery models using home BP monitoring have demonstrated improved BP control.

 Demonstrating the benefits, costs, and cost effectiveness of such programs will help clinicians and policy makers to decide whether to invest in these programs.

Investigators at Kaiser Permanente Colorado (KPCO) conducted a randomized, controlled trial to evaluate the effectiveness of a home BP monitoring (HBPM) intervention that used the American Heart Association Heart360 Web interface (

) to send home BP readings to a clinical pharmacy specialist who managed the patient’s medication therapy via phone or e-mail communication. The purpose of this study was to determine the cost-effectiveness of the HBPM program compared with usual care.

The study was conducted at KPCO, a group-model, closed-panel, nonprofit managed care organization that cares for more than 500,000 members in the Denver-Boulder metropolitan area. Outpatient medical services are provided at 18 primary care clinics spread geographically across the metropolitan area, 10 of which participated in the present study. Each clinic is staffed with 1 or more clinical pharmacy specialists who assist primary care providers with drug therapy management. With regard to hypertension management, clinical pharmacy specialists work under preapproved collaborative drug therapy management protocols that permit them to initiate or change antihypertensive medications, adjust medication doses, and order laboratory tests related to medication monitoring. KPCO clinicians use a commercially available EpicCare electronic health record (EHR) as part of routine care delivery. The KPCO EHR has a feature called My Chart which allows patients and their providers to communicate electronically through a password-protected website.

The study was approved by the KPCO Institutional Review Board.

The HBPM study has been described in detail elsewhere. 8 This was a randomized, controlled study of 348 patients with uncontrolled hypertension randomly assigned to the HBPM program or usual care. Patients in the HBPM group were provided with and trained to use a home BP monitor (Omron HEM-790IT monitor), and they were guided in establishing a Heart360 account and in how to automatically upload BP measurements from their monitor to their Heart360 account. Patients in the HBPM group also met with a clinical pharmacy specialist, who reviewed their current BP medication regimen, provided counseling on lifestyle changes, and adjusted or changed antihypertensive medications, as needed. Patients in the usual care group were instructed to follow up with their primary care physician for BP care. Patients in both groups returned at 6 months for an in-clinic BP measurement. Blood pressure goal was <140/90 mm Hg for all patients, except for those with diabetes mellitus or chronic kidney disease for whom the goal was <130/80 mm Hg. At 6 months, 54% of patients in the HBPM group attained their BP goal, compared with 35% in the usual-care group (

 <.001). The HBPM group lowered their systolic blood pressure (SBP) by an average of 21 mm Hg compared with 8 mm Hg in the usual care group (

The economic analysis was conducted from the health plan perspective over the 6-month study period. Cost inputs included costs of the blood pressure cuff, clinic visits, e-mail and telephone encounters, laboratory tests, medications, hospitalizations, and emergency department (ED) visits. Indirect costs (eg, the administrative costs necessary for day-to-day operations) were not included as they were not expected to differ between the groups.

Healthcare utilization data were collected for 6 months prior to and after study enrollment using administrative databases maintained by KPCO. Data included all outpatient encounters (office visits, telephone contacts, e-mails), laboratory and radiology tests, prescriptions, ambulatory surgery, ED visits, and hospital admissions both within the KPCO system as well as claims for care that occurred outside KPCO. Costs were classified as hypertension-related if the primary 

International Classification of Diseases, Ninth Revision, Clinical Modification

 code associated with each expenditure was hypertension (401.9); hospitalizations, clinic encounters, and ED visits were reviewed manually to verify accurate categorization. Current procedural terminology codes were used to assign costs according to a fee schedule derived from the 2009 national Medicare fee schedule.

Costs for professional claims were based on billed amounts. Prescriptions billed through insurance were collected during the same time frame, and costs were determined using discounted average wholesale price to approximate Medicare pricing, with the addition of an $8 dispensing fee.

Costs for the initial clinic visit, telephone encounters with a clinical pharmacy specialist, and all e-mail encounters were estimated by multiplying the time spent by each provider type by the hourly wage. Provider compensation rates were taken from the United States Census Bureau wages and compensation 2009 data plus 29.2% to account for benefits.

The following hourly rates were used: pharmacist, $74.14; medical assistant, $19.39; registered nurse, $44.09; and physician, $99.72. The initial clinic visits differed in that the HBPM group required an additional 20 minutes of medical assistant time for training on the home BP monitor, setting up a Heart360 account, and downloading BP readings to the website, plus 20 minutes with a clinical pharmacy specialist to review antihypertensive medications and make any necessary dose adjustments. Based on a survey of the clinical pharmacy specialists participating in the study, pharmacist time was estimated at 10 minutes for each telephone follow-up encounter. E-mails from any provider were estimated at 6 minutes per e-mail encounter. All costs have been adjusted to reflect 2013 dollars using the Consumer Price Index rates for medical costs.16 The selected home BP monitor or a similar model can be purchased for approximately $60.

Direct costs were grouped into the following categories: outpatient encounters (including in-person clinic visits, telephone calls, and e-mail exchanges); outpatient laboratory; pharmacy outpatient; and all other costs (ambulatory surgery, ED, hospitalizations, and outpatient radiology). Total healthcare costs for 6 months prior to enrollment were compared between groups to assess for baseline differences in costs and to adjust for such differences (if present) during the study period. Total and hypertension-related costs during the 6-month study period were calculated to demonstrate the relationship between hypertension-related and total healthcare costs and to capture any unintended increases in healthcare utilization (eg, due to adverse events) related to the study. Three incremental cost-effectiveness ratios (ICERs) were calculated: cost per mm Hg lowering of SBP per patient, cost per controlled BP achieved, and cost per life-year gained. To determine the cost of an additional 1 mm Hg lowering of SBP in a patient, the mean difference in 6-month costs for hypertension care was divided by the mean SBP change in each group. To determine the cost of 1 patient achieving BP control, the mean difference in 6-month hypertension-related costs was divided by the difference in the number of patients achieving control in each group.

Cost per life-year gained was determined by first calculating the discounted life expectancy (DLE) for each patient at baseline and after the intervention using the formula:

=1.5% is the discount rate for life years,

is the current age of the patient in years, and 

 denotes the probability of surviving until age 

 denotes the 1-year risk of death for a patient of age s with the same gender and BP control level as the patient. (The symbol Π denotes the product operator; for example 

 ). The mortality rates were estimated from life expectancy data based on age, gender, and BP control level.18 The mortality rate for a patient of age s years was calculated by the formula:

 is the life expectancy of a patient of age s of the same gender and BP control level; this was determined by linear interpolation or extrapolation from Tables 3, 

 The mortality rate formula was derived by assuming that deaths occur at the end of each year so that:

We calculated the incremental hypertension care costs of the intervention for year 1 of the program plus subsequent years of follow-up. Total hypertension care cost in each group for year 1 was calculated by first estimating the increased cost of antihypertensive medications for the entire year for each patient. To account for expected follow-up needs in the second 6-month period, the costs for non—study-related outpatient encounters in the first 6 months was doubled and an additional e-mail encounter was added for intervention patients. Additional laboratory costs were not added for the second 6-month period because most antihypertensive medications require annual monitoring. To determine the incremental hypertension care cost for each intervention patient in year 1, the mean cost of a usual-care patient was subtracted from the actual cost for each intervention patient. Incremental cost for subsequent years was calculated as the average difference in costs for antihypertensive medication plus laboratory monitoring between groups plus the cost of 3 e-mail encounters in the intervention group.

The discounted cost of intervention for each patient in the intervention group was calculated by the formula:

where rc = 3% is the discount rate for costs,

 is the incremental hypertension care cost for intervention patients in year 1 as described above, and 

 is the incremental cost for each subsequent year. Subset analyses were performed on the group of patients with diabetes mellitus to calculate the incremental cost-effectiveness ratios for this high-risk group.

Cost comparisons between each group were reported as median and interquartile range values as cost data were not normally distributed. Wilcoxon rank sum was used to determine the significance of the between-group differences in cost. Level of significance was set at an α of 0.05. All statistical analyses were performed using SAS version 9.2 (SAS Institute, Carey, North Carolina).

The average age of the 348 study participants was 60 years; about 60% were male (

). Almost half of the participants had either diabetes mellitus or chronic kidney disease (Table 1).

Compared with patients in the usual care group, patients in the HBPM group had significantly more e-mail (median 5 vs 1, 

 <.001) encounters during the 6-month study period. There were no statistically significant differences between the 2 groups in the number of office visits, ED visits, or hospitalizations over the 6-month study period (

There were no statistically significant differences in total costs for the intervention and usual care groups in the 6-month pre-enrollment period (

 = .828 for total costs). Median total healthcare costs per patient during the 6-month study period were higher in the HBPM group ($1590) than in the usual care group ($1283; 

). This difference was largely driven by higher outpatient encounter costs ($481 vs $381, 

 = .006) and higher medication costs ($622 vs $475, 

 = .034) for HBPM and usual care groups, respectively.

When only considering hypertension-related costs, all major cost categories were higher in the HBPM group (median hypertension-related care cost of $455 per patient) compared with usual care (median cost $179; 

 <.001, Table 3). The incremental hypertension-related cost per additional mm Hg reduction in SBP was $20.50. The incremental hypertension-related cost per patient who achieved BP control was $1331 (

Articles

A technology-based, pharmacist-run home blood pressure monitoring program improves health outcomes by investing $20.50 per mm Hg systolic blood pressure lowered and $3300 per life-year gained.

Cost-effectiveness Evaluation of a Home Blood Pressure Monitoring Program

Despite the significant prevalence of elevated blood pressure (BP) and body mass index (BMI) in children, few studies have assessed their combined impact on healthcare costs. This study estimates healthcare costs related to BP and BMI in children and adolescents.

Prospective dynamic cohort study of 71,617 children aged 3 to 17 years with 208,800 child years of enrollment in integrated health systems in Colorado or Minnesota between January 1, 2007, and December 31, 2011.

Generalized linear models were used to calculate standardized annual estimates of total, inpatient, outpatient, and pharmacy costs, outpatient utilization, and receipt of diagnostic and evaluation tests associated with BP status and BMI status.

Total annual costs were significantly lower in children with normal BP ($736, SE = $15) and prehypertension ($945, SE = $10) than children with hypertension ($1972, SE = $74) (

 <.001, each comparison), adjusting for BMI. Total annual cost for children below the 85th percentile of BMI ($822, SE = $8) was significantly lower than for children between the 85th and 95th percentiles ($954, SE = $45) and for children at or above the 95th percentile ($937, SE = $13) (

This study shows strong associations of prehypertension and hypertension, independent of BMI, with healthcare costs in children. Although BMI status was also statistically significantly associated with costs, the major influence on cost in this large cohort of children and adolescents was BP status. Costs related to elevated BMI may be systematically overestimated in studies that do not adjust for BP status.

Prehypertension and hypertension have strong effects on healthcare costs in children, independent of body mass index (BMI).

This study examines the combined impact of blood pressure (BP) and BMI on healthcare costs.

Although BMI status was associated with costs, the major influence on cost in this large cohort of children and adolescents was BP status.

Costs related to elevated BMI may be systematically overestimated in studies that do not adjust for BP status.

The potential long-term adverse outcomes associated with prehypertension (preHT) and hypertension (HT) in children and adolescents are well recognized.

 Blood pressure (BP) in youth correlates with BP in early adulthood and may be associated with elevated cardiovascular (CV) risk later in life.

 Moreover, elevated BP is associated with elevated body mass index (BMI) in children and adolescents,

Because of the acknowledged increased CV risk associated with childhood preHT or HT, it seems reasonable to suggest that healthcare costs would also increase with preHT or HT as the result of increased testing and evaluation, increased follow-up, or increased CV-related comorbidities. However, information on the cost related to elevated BP in children is scarce.

 Studies of obese children suggest modestly elevated costs of care, but none of these prior studies consider the fact that elevated BMI is significantly related to elevated BP.

Studies assessing the relation between BMI and healthcare costs, but failing to account for BP levels or other clinical conditions associated with elevated BMI, may overestimate the independent impact of BMI.

 In this project, we model the association of elevated BP and costs, while taking into account detailed data on BMI and other comorbid conditions (including depression and other mental health conditions). Using this broader approach permits a more accurate assessment of healthcare costs in children and adolescents with elevated BP than data currently available in the literature.

  Electronic health records (EHRs) were used to identify a dynamic, longitudinal cohort of children and adolescents who were enrolled in 2 large integrated health maintenance organizations in Colorado and Minnesota. Children and adolescents aged 3 to 17 years were included in the study if they were continuously enrolled in the health plans for 1 or more years from January 1, 2007, to December 31, 2010; had measured height, weight, and BP; and had comprehensive insurance coverage including coverage for pharmaceuticals. Only BP measurements obtained in primary care outpatient clinics were included in this study; BP measurements obtained in the emergency department (ED) or urgent care centers were excluded.

Both health plans used an EpiCare (Verona, Wisconsin) EHR. Demographics, including age, gender, and race/ethnicity, were derived from administrative eligibility data. BMI and presence of preHT and HT were ascertained from EHR vital signs data. Age and gender-specific BMI percentiles were calculated for each visit in which both height and weight were measured, and children and adolescents were assigned their maximum BMI percentile during the study period. Age, gender, and height-specific BP percentiles were calculated for both systolic BP and diastolic BP measures obtained in outpatient settings (including emergency departments and urgent care clinics)

Children who had 3 or more BP measurements taken during the study period were included. Normal BP was defined as having all systolic BP and diastolic BP measurements < 90th percentile; preHT was defined as having 1 or more BP measurements ≥90th percentile or ≥120/80 mm Hg; HT was defined as either 3 consecutive BP measurements ≥95th percentile or 1 or more BP measurements ≥99th percentile. Children were also identified as having HT if they received a diagnosis of essential hypertension from their healthcare provider during the study period (

International Classification of Diseases, Ninth Revision, Clinical 

 [ICD-9-CM] codes 401.xx). To focus this study on essential hypertension, children diagnosed with secondary hypertension (ICD-9-CM codes 405.xx) or other cardiovascular conditions were excluded. Normal BMI was defined as <85th percentile, overweight as ≥85th to <95th percentile, and obesity as ≥95th percentile.

EHRs accurately measure utilization, but do not directly measure resource use or costs. Therefore, we applied standard pricing methodologies to estimate annual inpatient, outpatient, and pharmacy costs.

 Inpatient admissions were priced using nationally representative 2010 payment rates based on Diagnostic Related Groups. Costs for outpatient services including physician, outpatient hospital, and clinic services; costs for all other outpatient services such as nursing services, laboratory, and radiology were priced using the nationally representative 2010 payment rates per relative value unit. Costs for phar- maceuticals, including prescriptions for antihypertensive and other medications, were priced at 68% of their average wholesale prices in 2010.

We examined utilization of outpatient services to determine whether preHT and HT might be driving utilization and costs through increased diagnostic testing and evaluation. We used procedure codes to estimate the annual number of preventive, office, or outpatient medical visits and the number of outpatient psychiatry and psychology visits. We also identified the likelihood of ED services or specialist consultations. In addition, we identified the likelihood of receiving diagnostic procedures including urinalysis, laboratory testing, chest x-ray, electrocardiogram, renal ultrasound, and echocardiogram.

We measured medical comorbidities using the Chronic Illness and Disability Payment System (CDPS).

 CDPS is a combined diagnostic and pharmacy-based risk adjustment model commonly used to measure illness burden and to adjust capitated payments to health plans. The CDPS algorithm assigns ICD-9-CM diagnosis codes to 58 diagnostic categories including selected mental health conditions, and national drug codes to 15 pharmaceutical categories, and applies severity weights developed from a national database of medical claims. The resulting CDPS score provides a measure of illness burden based on expected future healthcare expenditure conditional on each person’s diagnostic and pharmaceutical profile.

We analyzed inpatient, outpatient, pharmacy, and total costs using generalized linear models. Generalized linear models are commonly used to estimate healthcare costs when the dependent variable is non-negative and when its distribution is noticeably skewed and kurtotic (with a heavy right-hand tail).

 Inpatient and pharmacy costs were estimated using 2-part models: logistic regression was used to estimate the probability of any use of a service, and a generalized linear model based on a gamma family with a log link function was used to estimate costs conditional on receiving at least 1 service. Total and outpatient costs was estimated using a single generalized linear model. The number of preventive, office, or outpatient visits and the number of outpatient psychiatry and psychology visits were estimated using negative binomial regression, and the probability of receipt of each of the remaining measures of outpatient utilization were estimating using logistic regression. We selected these specific distributions based on standard tests for assessing alternative generalized linear and transformed models.

 We assessed goodness of fit using a modified Hosmer-Lemeshow test and a Pregibon’s link test.

The primary predictor variables of interest were indicator variables for BMI ≥85th to <95th percentile, BMI ≥ 95th percentile, preHT, and HT. Analyses of BMI were adjusted for HT, and analyses of HT were adjusted for BMI. Additional control covariates included age (specified as a set of indicator variables with 1 for each year), gender, race/ethnicity, site, and year. We conducted analyses with and without controlling for comorbidity using the CDPS score. Controlling for comorbidity may reduce confounding of the cost estimates if increased illness burden is correlated with BP or BMI status. However, it may be inappropriate to adjust for comorbidity if an increased illness burden is the result of BP or BMI status. Therefore, we conducted 2 sets of analysis to provide a range of estimates and to demonstrate the sensitivity of the estimates to medical comorbidities.

We calculated cost estimates associated with BMI, preHT, and HT that were adjusted for age, sex, race/ ethnicity, CDPS score, and either BMI or BP status. For example, the standardized costs of children with pediatric HT were calculated as the mean predicted values across all children assuming they all had pediatric HT. Standard errors were calculated using the nonparametric bootstrap, and P values were computed using the percentile method from the empirical distributions of the results from 1000 replicates.

All analyses were conducted in STATA, version 12.

This project was reviewed in advance, approved, and monitored by the HealthPartners Institute for Education and Research Institutional Review Board.

The study sample included 71,617 children aged 3 to 17 years followed for 35.0 (SD = 13.7) months and providing 208,800 child years of data. Study sample characteristics are shown in 

. The mean age was 10.3 (SD = 4.4) years, and 51% were female. The majority (57%) were non-Latino white, 14% were Latino, 10% were African American, and 4% were Asian. Native American, Hawaiian / Pacific Islander, or multiple races were 1% or less, and 14% were of unknown race/ethnicity. BMI percentile was normal in 64%, 18% were overweight, and 18% were obese. BP percentile was normal in 55%, 42% were prehypertensive, and 3% had hypertension. Among children identified with hypertension, 83% were identified using only BP measures. Among the 17% with an ICD-9-CM code for essential hypertension, 35% had BP measurements consistent with the diagnosis, while 65% did not have 3 consecutive BP measurements ≥95th percentile, and 31% filled prescriptions for antihypertensive medications. Among the 83% identified by BP only, 2% filled prescriptions for antihypertensive medications.

 shows the mean standardized annual costs among children by BMI and BP status without controlling for additional morbidity. Estimates of costs related to BMI were adjusted for HT, and estimates of costs related to HT were adjusted for BMI. There were no statistically significant interactions between BP and BMI status. As noted in 

, costs for children with preHT ($945, SE = $10) were significantly higher than for children with normal BP ($736, SE = $15), and annual costs for children with HT ($1972, SE = $74) were significantly greater than for children with preHT or normal BP (P <.001 each). Among children with hypertension, there was no difference in total costs between children who received a diagnosis of hypertension compared to children who were identified only by BP measures in the EMR review (P = .814). The largest cost component for all 3 BP groups was outpatient care, followed by pharmacy and inpatient care.

There were smaller cost differentials related to BMI. Total annual cost for children below the 85th percentile of BMI ($822, SE = $8) was significantly lower than for children between the 85th and 95th percentiles ($954, SE = $454) and for children at or above the 95th percentile ($937, SE = $13;) (P <.001 each). Total annual cost for children between the 85th and 95th percentiles of BMI was not statistically significantly different from the total cost for children above the 95th percentile (P = .754).

 shows that the standardized cost differentials between categories narrowed when controlling for additional comorbidity using the CDPS score. The differential in total costs between HT and normotensive children declined by $383 (SE = $90) to $852 (SE = $53), and the cost differential between preHT and normotensive children declined by $67 (SE = $18) to $141 (SE = $9) (P <.001 each) when adjusting for additional comorbidity using CDPS. The differentials in total cost for children above the 95th percentile of BMI and children between the 85th and 95th percentiles compared to children below the 85th percentile declined by $67 (SE = $19, P <.001) and $64 (SE = $48, P = .192), respectively, to $48 (SE = $11, P <.001) and $68 (SE = $15, P <.001) when adjusting for additional comorbidity using CDPS.

 shows estimates of outpatient utilization associated with preHT and HT. There were statistically significant increases in all measures of utilization except for laboratory testing. Utilization was at least 50% higher in HT than normal BP children in all categories, except for laboratory testing (P <.001 each), with the large percentage increases observed for renal ultrasound, echocardiogram, and chest x-ray. However, these procedures were performed at a relatively low rate, and all diagnostic and evaluation procedures with the exception of urinalysis were conducted in fewer than 10% of children with HT. We reviewed the types of specialist consultations, but could not identify any specific pattern to differentiate visits among the BP categories.

The present study shows the strong incremental effects of both preHT and HT, independent of BMI and comorbidity, on healthcare costs in children. Although BMI status also was significantly associated with cost, the major influence on cost in this large cohort of children was BP status. It should be noted that the percent of children with preHT was higher than previously reported.

Because the definition for preHT requires only a single BP measurement, the requirement of 3 separate clinic BP measurements for inclusion in this study increased the number with preHT.

An important factor in this analysis is that hypertension was identified primarily from review of EHRs, with only 17% recognized by the clinic physicians. The lack of recognition of HT by providers using computerized medical record systems has been reported previously,

as has the extent of the underrecognition.

However, there was no significant difference in cost associated with the EHR method, as opposed to physician recognition and diagnosis. Thus, there may be something inherent in the presence of hypertension or prehypertension that leads to increased outpatient and emergency department visits, specialist consultations, increased diagnostic and evaluation procedures, and their associated costs; or medical issues resulting in more frequent clinic visits with greater number of BP measurements resulting in a larger number of diagnoses of preHT or HT. This may account for the significantly greater use of cardiac studies and chest x-rays in the subjects with hypertension.

Elevated BP in adults has been shown to be associated with substantial increased costs in 3 national data sets.

 Studies of adults have further shown that both obesity and hypertension are independent determinants of costs.

In contrast, little attention has been devoted to the costs or to strategies to address elevated BP in children or adolescents. Given the strong relationship between elevated BP and healthcare costs, a case could be made to health plans and payers to consider implementing strategies to manage healthcare utilization of children with elevated BP. These strategies might include improved primary care, case management, health behavior interventions, family education, or other interventions.

In contrast to prior studies, costs of healthcare services in this study were not significantly different between overweight (BMI ≥85th percentile to < 95th percentile) and obese (BMI ≥95th percentile) children controlling for BP status. Studies assessing healthcare utilization and cost related to overweight or obesity previously have not been able to adjust for BP status due to lack of BP data. By including both BMI and BP status in the analyses, this study has been able to extend previous findings by showing that the effect of BMI is lower than previously reported and is confounded by the associated impact of preHT and HT.

These findings are relevant to ongoing clinical and public policy discussions. First, they suggest that greater attention should be paid to elevated BP in children and adolescents as a driver of healthcare costs. Second, elevated BP has a significant effect on cost independent from elevated BMI and other comorbid conditions. Third, studies that do not account for the impact of BP level on utilization may overestimate the effect of BMI on utilization and costs.

There are limitations that should be considered in the interpretation of these data. First, despite the large, racially and ethnically diverse study population, these results may not be generalizable to costs of care in non—insurance-driven healthcare systems. However, it is currently challenging to conduct this type of study and capture detailed clinical and cost data outside the highly integrated healthcare systems included in this study. Second, it is possible that some allopathic care was obtained outside the insurance system, although prior studies suggest that this is well under 5% of total allopathic care. Third, although we adjusted for comorbidity using CDPS, there may be some residual differences in comorbidities by BP status. Finally, the results from this study do not imply causality between hypertension and the increased cost of patient care. However, the data clearly show an association between BP and healthcare costs in youth.

Department of Family and Preventive Medicine, University of California, San Diego (TPG); HealthPartners Institute for Education and Research, Minneapolis, MN (PJO, EOK, NES, KFA, KLM); Department of Pediatrics, University of Minnesota, Minneapolis (ARS); Institute for Health Research, Kaiser Permanente Colorado, Denver (DJM).

Funding was provided by the National Institutes of Health grant R01HL093345 from the National Heart, Lung, and Blood Institute.

 The authors report no relationship or financial interest with any entity that would pose a conflict of interest with the subject matter of this article.

Concept and design (TPG, PJO, ARS, EOK, KLM); acquisition of data (PJO, KLM); analysis and interpretation of data (TPG, PJO, ARS, EOK, DJM, NES, KFA, EDP, KLM); drafting of the manuscript (TPG, PJO, ARS); critical revision of the manuscript for important intellectual content (TPG, PJO, ARS, EOK, DJM, NES, KFA, EDP, KLM); statistical analysis (TPG); provision of study materials or patients (PJO); obtaining funding (PJO, ARS, NES); administrative, technical, or logistic support (TPG); supervision (TPG, POC).

Todd Gilmer, PhD, Department of Family and Preventive Medicine, University of California, San Diego, 9500 Gilman Dr, La Jolla, CA 92092-0622. E-mail: tgilmer@ucsd.edu.

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This study demonstrates a major influence of prehypertension and hypertension on healthcare costs in a large cohort of children, independent of body mass index.

Impact of Hypertension on Healthcare Costs Among Children

To evaluate whether systolic blood pressure (SBP) control is maintained following participation in a multimodal hypertension intervention.

 This was a retrospective cohort of patients completing the Improving Blood Pressure in Colorado study, a randomized trial comparing a multimodal intervention with usual care for patients who had uncontrolled hypertension. Chart review assessed the first SBP measurement recorded as part of routine care after the study ended. Among patients who had controlled SBP at the final study visit, the proportions who had uncontrolled SBP during follow-up were compared for the intervention and usual care (UC) groups. Kaplan-Meier estimates assessed time to uncontrolled SBP by treatment arm.

Of 283 patients completing the Improving Blood Pressure in Colorado study, 51.5% in the intervention and 46.9% in the UC group had controlled SBP at the final study visit. Of patients with controlled SBP, 37.0% and 46.4% of patients in the intervention and UC groups, respectively, had uncontrolled SBP at their initial measurement during follow-up (

 = .32). There was no difference in median time to uncontrolled SBP (126 vs 114 days for the intervention and UC groups, respectively; 

SBP control was not maintained in a significant proportion of patients in both groups following hypertension study participation. These findings suggest the need for interventions to focus on longer-term BP control in contrast to the short duration of most hypertension intervention trials.

	A randomized trial compared a multimodal intervention with usual care for patients who had uncontrolled hypertension.

		Systolic blood pressure control was not maintained in a significant proportion of patients in both groups following participation in this study.

		These results suggest the need to focus on long-term hypertension control.

	Approximately 65 million US adults have hypertension and this number is expected to grow as the population ages.

Hypertension is a significant cardiovascular risk factor and the Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC 7) recommends achieving systolic blood pressure (SBP) goal as the primary focus of hypertension therapy.

Although the degree to which SBP is lowered is directly related to the degree to which adverse outcomes are reduced, national surveys demonstrate that only about half of patients with hypertension have their blood pressure (BP) treated to levels recommended by guidelines.

 Further, BP control over time is directly associated with cardiovascular events, suggesting that both achieving and maintaining BP goals are important.

	Interventions using pharmacists, nurses, home BP monitoring, and/or technology such as interactive voice response (IVR) alone or in combination have resulted in improved BP control compared with usual care in the short term (6-12 months).

 However, given that hypertension is a chronic condition, long-term management is necessary. Unfortunately, little is known about maintenance of BP control following patients’ participation in hypertension intervention studies or about the durability of BP reduction after the conclusion of a study.

	The Improving Blood Pressure in Colorado study was a randomized study that evaluated a multimodal intervention for patients with uncontrolled hypertension, utilizing IVR technology and clinical pharmacist— physician management for 6 months.

 The objective of the current study was to evaluate maintenance of SBP control in the short term after participation ended in the clinical trial, when patients returned to their primary care providers for care.

	The Improving Blood Pressure in Colorado study (clinicaltrials. gov; Identifier: NCT00520988) was conducted from 2006 to 2009 at 3 healthcare systems across the Denver metropolitan area, including the Denver Veterans Affairs Medical Center, Kaiser Permanente Colorado, and the Denver Health Medical Center. The randomized study was approved by the institutional review board at each site. The current study was approved as an addendum to the initial study and included patient waiver of consent.

Methods for the Improving Blood Pressure in Colorado Study

	Criteria for enrollment into the main prospective, randomized study were the following: 18 to 85 years of age, diagnosed with hypertension, uncontrolled BP (>140/90 mm Hg, or >130/80 mm Hg for patients with diabetes or chronic kidney disease), and receiving <4 antihypertensive medications. All patients attended a baseline, in-person clinic visit to have their BP assessed. Three BP measurements were obtained and if the average of the latter 2 measurements was above patient-specific targets, those patients were eligible for enrollment. Patients randomized to the intervention were provided a hypertension educational booklet from the National Institutes of Health (

), instruction on the use of the IVR system, and an electronic BP monitoring machine. Patients were taught how to measure home BP, instructed to take their BP 3 to 4 times per week, and told to report their BP readings via IVR weekly. A clinical pharmacist reviewed the BP entries from the IVR system and managed BP via telephone visits, utilizing treatment protocols approved by primary care physicians. Patients randomized to usual care were given the same educational booklet on hypertension and instructed to follow up with their primary care providers for BP management. All patients returned at 6 months and had 3 BP readings taken, with the latter 2 averaged to determine the final BP reading for the study. The person obtaining the final readings was blinded to patient group assignment. Blood pressure control was defined as <130/80 mm Hg for patients with diabetes or chronic kidney disease and <140/90 mm Hg for all others.

	To evaluate maintenance of SBP control following patient participation in the current study, we performed chart reviews for all participants who completed the end-of-study visit (n = 283). We abstracted BP measurements taken as part of routine clinical care at all outpatient nonemergent care visits within 6 months following the end of participation in the clinical trial. Data were collected for both intervention and usual care group patients. Patients with no follow-up BP values in the 6-month period (n = 55) were not included in the analysis. The primary outcome for the follow-up study was the proportion of patients with uncontrolled SBP using JNC 7—defined goals (ie, SBP >140 mm Hg, or >130 mm Hg for those with diabetes or chronic kidney disease) based on their first BP measurement following the end of participation in the Improving Blood Pressure in Colorado study.

	Descriptive statistics (means, standard deviations, and percentages) were used for patient demographics at baseline for each group. X

 tests for continuous variables were used for group comparisons between intervention and usual care patients. Kaplan-Meier estimates were used to model the probability of uncontrolled SBP by follow-up time for each treatment arm. To identify predictors of uncontrolled SBP, a multivariable logistic regression model was created, using baseline characteristics at the time of participation in the clinical trial and included all 

variables. As a secondary analysis, we also assessed the proportions of patients with uncontrolled SBP in the intervention and usual care groups by averaging all available SBP measurements during the initial 6 months following the end of study participation. Statistical analyses were performed using SAS version 9.2 (SAS Institute, Inc, Cary, NC).

	Of the 283 patients who completed the Improving Blood Pressure in Colorado study, 51.5% (71/138) in the intervention group and 46.9% (68/145) in the control group had controlled SBP at the final study visit. The magnitude of SBP reduction was greater in the intervention group than in the usual care group despite similar rates of patients with controlled SBP (-13 mm Hg vs -7 mm Hg for the intervention group vs the usual care group, respectively; 

 = .004). More than 24% (n = 34) and 14% (n = 21) of the intervention and usual care group members, respectively (

 = .03), did not have follow-up BP measurements within 6 months of study completion. Patients with a BP measurement following study completion were older than patients without a BP measurement (65.4 vs 61.5 years; 

 = .02), but other baseline characteristics were comparable (Table 1).

	Baseline characteristics of patients with BP measurements within the 6 months following study end were comparable, including the number of patients with diabetes or chronic kidney disease (

). The mean and median numbers of BP measurements in the 6 months after end of study participation were 2.8 and 2.0, respectively. The median time to first BP assessment was 48 days with no difference between treatment groups (45.5 vs 51.0 days [

), with SBP increasing from 128 mm Hg to 139 mm Hg. Of the 56 usual care patients whose SBP was controlled at the end of the study, 46.4% (n = 26) had out-of-control SBP at their first follow-up, with SBP increasing from 129 mm Hg to 143 mm Hg (

 = .32 for comparison between treatment arms for the percentage of patients with uncontrolled SBP and 

 = .60 for comparison between groups for average SBP at first follow- up). There was no significant difference in the median time to uncontrolled SBP for intervention (126 days) and usual care (114 days) patients (

 = .47). In the assessment of factors associated with follow-up SBP control, only SBP control at end of study was associated with subsequent control (odds ratio, 0.31; 95% confidence interval, 0.16-0.57).

	In secondary analysis (when we used all available SBP measurements taken during the 6 months after the study ended), a similar proportion of intervention (29.6%) and usual care (29.1%) patients had uncontrolled SBP. For patients with uncontrolled SBP at the study’s end, 70% (n = 35) of intervention patients and 63.2% (n = 43) of usual care patients continued to have uncontrolled SBP at their first assessment following the study (

	The objective of this study was to describe SBP control following participation in a hypertension intervention study, when patients returned to their usual care settings. Among patients whose SBP was controlled at the end of the study, 42% had out-of-control SBP at the first BP measurement obtained within 6 months of study completion. Among patients whose SBP was not controlled at the end of the study, the majority continued to have uncontrolled SBP during follow-up (~66%). These findings highlight the difficulty of maintaining SBP control and suggest the importance of trying to obtain consistent BP control over time rather than control at discrete time points.

	Little is known about SBP control following participation in hypertension intervention studies. To date, only 1 prior published study assessed BP control following participation in a hypertension intervention study, which compared a physician— pharmacist collaborative intervention with usual care. Carter et al showed that at 9 months following the completion of the study, SBP had worsened for both intervention and control patients, although to a greater degree in the usual care group.

 In their study, approximately one-third of patients whose SBP was controlled at the end of the study lost that control at 9 months. In contrast, we found that a greater proportion of patients developed uncontrolled SBP and that the uncontrolled SBP developed much sooner, at around 4 months in our patient population. These findings demonstrate that gains in SBP control made during the study were not sustained. Future studies should identify potential reasons for loss of SBP control, including nonadherence to medications or lifestyle changes.

	The findings of our study highlight the importance of approaching hypertension control longitudinally rather than at discrete time points. This conclusion is supported by studies that have demonstrated that ambulatory BP measurements (which generally include more measurements over time) predict cardiovascular outcomes better than clinic BP measurements. 

 In addition, the INVEST Study showed that a higher proportion of visits where BP was controlled (which indicated consistency of control) were associated with a reduction in death, nonfatal myocardial infarction, or stroke.

 Despite the importance of longitudinal BP control, national epidemiologic studies such as the National Health and Nutrition Examination Survey and quality-of-care performance measures from the Healthcare Effectiveness Data and Information Set still assess BP control based on measurements at 1 point in time or a single measurement, which may overlook the chronic nature of hypertension.

Future studies are needed on how to better define hypertension control for epidemiologic studies and for quality-of-care assessment, incorporating the variability of BP.

	Potential limitations of the study should be acknowledged. First, approximately 19% of patients did not have a BP measurement within 6 months following the end-of-study visit. We do not know whether these patients had a follow-up visit scheduled with their primary care provider. However, our findings that SBP became uncontrolled shortly after the end of study participation suggest that interventions are needed for routine follow-up of patients with hypertension to ensure that BP is assessed regularly and adequately controlled. These findings differ from those in hyperlipidemia studies (in which low-density lipoprotein cholesterol control was maintained following discharge from a lipid intervention program) and might be related to the greater variability of hypertension.

 Prior studies have not assessed glucose control in patients with diabetes following their participation in intervention studies. Second, this was a small study. It was underpowered to assess whether there was a difference in rates of uncontrolled SBP between intervention and usual care patients, despite an absolute difference of 9% in favor of the intervention patients. Future larger hypertension studies should assess the sustainability of intervention effects following the end of the clinical trial to better determine whether patients need additional interventions. Third, we cannot exclude the possibility that our findings reflected regression to the mean. However, in a secondary analysis when we used all available SBP measurements during the 6 months following study participation, the findings regarding the proportions of patients with out-of-control SBP were consistent with the primary analysis. Fourth, it is possible that BP was incorrectly measured during follow-up; however, those BP measurements reflect the BP measurement that was in the medical record and was used during routine clinical care for decision making. Finally, this study was conducted within 3 integrated healthcare systems and may not be generalizable to other healthcare settings. Additional studies are needed to assess the consistency of BP control following attainment of SBP goals in different healthcare settings.

	We found that patients whose SBP was controlled at the end of a hypertension intervention study lost SBP control quickly after they stopped participating in the trial. These findings suggest the need for interventions to focus on longerterm BP control, in contrast to the short duration of most hypertension intervention trials.

 From Denver VA Medical Center (LKW, LP, AL-K, PMH), Denver, CO; Department of Pharmacy (KLO), Kaiser Permanente of Colorado, Aurora; University of Colorado Denver (KLO, AL-K, EPH, DJM, PMH); Denver Health Medical Center (KES, EPH), Denver, CO; Institute for Health (DJM), Kaiser Permanente of Colorado, Denver.

 This work was funded by an award from the American Heart Association (0535086N).

 Dr Ho is supported by a VA Health Services Research and Development Award (05-026) and serves as a consultant for Wellpoint, Inc. He also reports having given lectures for Pfizer in Japan. The authors (LKW, KLO, KES, LP, AL-K, EPH, DJM) report no relationship or financial interest with any entity that would pose a conflict of interest with the subject matter of this article.

 Concept and design (LKW, KLO, KES, PMH); acquisition of data (KES, AL-K, EPH, DJM, PMH); analysis and interpretation of data (LKW, KLO, LP, AL-K, PMH); drafting of the manuscript (LKW, KLO); critical revision of the manuscript for important intellectual content (LKW, KLO, LP, EPH, DJM); statistical analysis (LP); provision of study materials or patients (KES); obtaining funding (EPH, DJM); administrative, technical, or logistic support (AL-K); and supervision (EPH).

Lesley K. Welch, PharmD, 1055 Clermont St, Denver, CO 80220. E-mail: Lesley.welch@va.gov.

1. Lloyd-Jones D, Adams RJ, Brown TM, et al; American Heart Association Statistics Committee and Stroke Statistics Subcommittee. 

Heart disease and stroke statistics—2010 update. A report from the American Heart Association. Circulation. 2010;121(7):e46-e215.

2. Chobanian AV, Bakris GL, Black HR, et al; National Heart, Lung, and Blood Institute Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure; National Heart, Lung, and Blood Institute; National High Blood Pressure Education Program Coordinating Committee.

 Seventh report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure. Hypertension. 2003;42(6):1206-1252.

Systolic blood pressure control was not maintained in a large proportion of patients after the end of participation in a hypertension intervention study.

Systolic Blood Pressure Control After Participation in a Hypertension Intervention Study

To determine if a multimodal intervention composed of patient education, home blood pressure (BP) monitoring, BP measurement reporting to an interactive voice response (IVR) phone system, and clinical pharmacist follow-up improves BP control compared with usual care.

Prospective study with patient enrollment, medication consultation and adjustment, remote BP monitoring, and follow-up at 6 months.

This randomized controlled trial was conducted at 3 healthcare systems in Denver, Colorado, including a large health maintenance organization, a Veterans Affairs medical center, and a county hospital. At each site, patients with uncontrolled BP were randomized to the multimodal intervention vs usual care for 6 months, with the  primary end point of BP reduction.

 Of 338 patients randomized, 283 (84%) completed the study, including 138 intervention patients and 145 usual care patients. Baseline BP was higher in the intervention group vs the usual care group (150.5/89.4 vs 143.8/85.3 mm Hg). At 6 months, BPs were similar in the intervention group vs the usual care group (137.4 vs 136.7 mm Hg, P = .85 for systolic; 82.9 vs 81.1 mm Hg, P = .14 for diastolic). However, BP reductions were greater in the intervention group vs the usual care group (−13.1 vs −7.1 mm Hg, P = .006 for systolic; −6.5 vs −4.2 mm Hg, P = .07 for diastolic). Adherence to medications was similar between the 2 groups, but intervention patients had a greater increase in medication regimen intensity.

A multimodal intervention of patient education, home BP monitoring, BP measurement reporting to an IVR system, and clinical pharmacist follow-up achieved greater reductions in BP compared with usual care.

	This practical clinical trial implemented across 3 healthcare systems showed that a multimodal intervention composed of patient education, home blood pressure (BP) monitoring, BP measurement reporting to an interactive voice response system, and clinical pharmacist management of hypertension led to greater BP reductions compared with usual care.

		This difference was likely due to greater therapy intensification (number and intensity of hypertension medications) in the intervention group, as adherence was comparable between the 2 study groups.

A multisite multimodal intervention of patient education, home monitoring, measurement reporting to an IVR system, and pharmacist follow-up achieved greater BP reductions vs usual care.

David J. Magid, MD, MPH

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