The American Journal of Managed Care November 2010
Persistent Asthma Defined Using HEDIS Versus Survey Criteria
HEDIS-defined persistent asthma is generally consistent with survey-defined persistent asthma over a 3-year period.
Objectives: To describe the relationships between persistent asthma defined by administrative versus survey data and their stability over time.
Study Design: Longitudinal survey and retrospective administrative database.
Methods: Administrative data were used to identify patients meeting the Healthcare Effectiveness Data and Information Set (HEDIS) criteria for persistent asthma in year 1 (2006). At the end of year 2 and on 3 occasions during year 3, patients were mailed a survey to define persistent asthma based on symptoms and medication use in the prior month and exacerbations in the prior 12 months. Administrative data were also used to define medical utilization for asthma in year 3.
Results: Of 13,833 eligible patients, 2895 (20.9%) returned the survey; 2751 of these respondents reported physician-diagnosed asthma, of whom 2517 (91.5%) had survey-defined persistent asthma. Patients having survey-defined persistent asthma (68.0%) were more likely to requalify as having HEDIS-defined persistent asthma in year 2 than patients not having survey-defined persistent asthma (22.2%). However, 81.6% of survey respondents who did not requalify as having HEDIS-defined persistent asthma in year 2 had survey-defined persistent asthma. Patients with survey-defined persistent asthma in year 2 had significantly more medical utilization for asthma in year 3 than patients without survey-defined persistent asthma. Approximately 82% of the 799 patients completing all 4 surveys had persistent asthma on all surveys.
Conclusions: HEDIS-defined persistent asthma is generally consistent with survey-defined persistent asthma. Persistent asthma usually remains persistent over a 3-year period, indicating that it is a stable characteristic of asthma for most patients. The low survey response rate suggests that further population-based studies will be necessary to confirm the validity and generalizability of our study findings regarding persistent asthma.
(Am J Manag Care. 2010;16(11):e281-e288)
Healthcare Effectiveness Data and Information Set (HEDIS)-defined persistent asthma seems to reflect clinical persistent asthma.
- The 2-year HEDIS definition is more specific for persistent asthma than the 1-year definition.
- Persistent asthma is associated with increased medical utilization compared with nonpersistent asthma.
- Persistent asthma seems to be persistent over a 3-year period and is an appropriate target for intervention.
The National Committee for Quality Assurance2 has developed an administrative data–based definition of persistent asthma as part of the Healthcare Effectiveness Data and Information Set (HEDIS) quality measurement program. This definition relies on asthma-coded medical visits and asthma-related pharmacy utilization and is meant to define a population for whom asthma controller therapy is indicated. However, studies3,4 have shown that only a modest relationship exists between this administrative data–based definition of persistent asthma and a definition based on patient report of symptoms. Moreover, findings from other studies5,6 suggest that 24% to 45% of patients who qualify as having persistent asthma in one year based on the HEDIS definition do not qualify again the next year. This raises the question of how persistent is persistent asthma. In other words, is persistent asthma a sufficiently stable characteristic of asthma to warrant the recommendation for long-term controller therapy? We are unaware of studies that have specifically addressed this question.
Because data suggest that patients who qualify for administrative data–based persistent asthma for 2 consecutive years have increased markers of asthma morbidity and are more likely to receive controller therapy,7 the HEDIS definition of persistent asthma for the purposes of assessing appropriate controller use has been modified to require qualification in each of 2 successive years.2 However, no studies to date have investigated the relationship of this 2-year administrative data–based definition of persistent asthma to persistent asthma as defined by patient report of symptom frequency, severity, and treatment. The objectives of this study were (1) to investigate the relationship of the 2-year HEDIS definition of persistent asthma to persistent asthma as defined by patient report, (2) to compare medical utilization for patients with versus without persistent asthma, and (3) to determine the persistence of persistent asthma over time.
This study was approved by the Kaiser Permanente SouthernCalifornia Institutional Review Board. Using computerized Kaiser Permanente Southern California inpatient, outpatient, pharmacy, and membership records, we identified patients aged 18 to 56 years with persistent asthma in 2006 (study year 1) based on their meeting 1 or more of the following HEDIS criteria: (1) 4 or more asthma medication dispensings, (2) 1 or more emergency department visits or hospitalizations with a principal diagnosis of asthma, or (3) 4 or more asthma outpatient visits with 2 or more asthma medication dispensings. Patients with continuous membership in 2007 who also met 1 or more of these HEDIS criteria in 2007 (study year 2) were considered to requalify for 2-year HEDIS-defined persistent asthma (Table 1). Only patients with continuous membership in Kaiser Permanente Southern California from 2006 to 2008 were included in the study.
The following additional information was captured from the Kaiser Permanente Southern California records: (1) sex, (2) age, (3) smoking status, (4) Medicare or Medi-Cal insurance, (5) hospitalization with asthma coded (International Classification of Diseases, Ninth Revision, Clinical Modification [ICD-9-CM] code 493.xx) as the primary diagnosis or as the
second diagnosis with another respiratory primary diagnosis, (6) emergency department visit with asthma coded (ICD-9-CM code 493.xx) as the primary diagnosis or as the second diagnosis with another respiratory primary diagnosis, (7) outpatient visit with asthma coded (ICD-9-CM code 493.xx) as a diagnosis, (8) any oral corticosteroid dispensing, (9) dispensings of more than 6 short-acting b-agonist canisters in a 12-month period, (10) any asthma controller dispensing, and (11) address. We successfully linked more than 95% of the addresses of our enrollees to census block groups and assigned block group–level income and education estimates in 2006 to patients by using the proprietary demographic estimates supplied by Nielsen Claritas (http://www.claritas.com). Census-based income and education variables have been widely used as proxies for the socioeconomic status of individuals in many health-related investigations.8 Using this method, we determined (1) the proportion of the population older than 25 years in the patient’s census block having more than a high school education and (2) the median household income in the patient’s census block. Medical utilization for asthma was assessed during 2006 (study year 1) and during 2008 (study year 3) (Table 1).
In November 2007, all eligible patients were mailed a survey to define persistent asthma based on symptoms and medication use in the prior month and exacerbations in the prior 12 months. The survey used the Expert Panel Report 3 definition of persistent asthma, which includes impairment and risk domains.1 The impairment domain includes the frequency and intensity of symptoms and functional limitations that the patient is currently experiencing. The risk domain includes the likelihood of asthma exacerbations based on the number of exacerbations in the prior 12 months. Four yes or no questions asked whether the patient in the past 30 days had (1) “experienced asthma symptoms at least 3 times per week,” (2) “used your rescue inhaler for symptoms at least 3 times per week,” (3) “been awakened by asthma symptoms at least 3 times,” and (4) had asthma that “interfered with your normal activity.” One question asked “In the past 12 months, how many times have you been given oral corticosteroids (such as prednisone, methylprednisolone, medrol) for a flare up of your asthma?” The final question regarding persistent asthma asked “Over the past 30 days, have you taken any of the following medications every day for your asthma?” and was followed by a list of controller medications with a yes or no option for each. A comparison of the HEDIS and survey definitions of persistent asthma is given in Table 2.
Patients who completed the baseline surveys were sent follow-up surveys in April, July, and October 2008 (Table 1). Only survey respondents who reported physician-diagnosed asthma on the baseline survey were included in the study.
The main analyses were directed at (1) identifying the relationships between HEDIS-defined persistent asthma (hereafter HEDIS persistent asthma) and survey-defined persistent asthma (hereafter survey persistent asthma) among patients completing the survey, (2) comparing medical utilization for asthma among patients with versus without persistent asthma, and (3) determining the persistence of persistent asthma over time. Hypothesis testing for comparisons of characteristics among survey responders versus nonresponders was by means of X2 test (categorical variables) or t test (continuous variables).
Survey Persistent Asthma Versus HEDIS Persistent Asthma. The presence or absence of survey persistent asthma on the baseline survey administered at the end of 2007 was assessed relative to requalification or nonrequalification for HEDIS persistent asthma in 2007 using X2 test.
Persistent Asthma Versus Medical Utilization. Hypothesis testing was conducted for the relationship between the presence of survey persistent asthma on the baseline survey at the end of 2007 (year 2) or HEDIS requalification in 2007 and medical utilization for asthma in 2008 (year 3). This was performed by means of X2 test.
Persistence of Persistent Asthma. Concordance between survey persistent asthma at baseline and on follow-up surveys was evaluated. Among patients who completed all 4 surveys, the proportions of patients with persistent asthma on 0, 1, 2, 3, or 4 surveys were determined.
Nominal 2-tailed statistical significance for all analyses was set at P <.05. All analyses were conducted using SAS version 9.13 for Windows (SAS Institute Inc, Cary, North Carolina).
A total of 13,833 patients aged 18 to 56 years met the HEDIS criteria for persistent asthma in 2006 and were continuously enrolled in Kaiser Permanente Southern California from 2006 to 2008. Of these, 2895 (20.9%) returned the November 2007 baseline survey; 144 denied a history of physician-diagnosed asthma, leaving a sample of 2751 survey respondents.
Compared with nonrespondents, respondents were more likely to be female, were older, lived in neighborhoods (census blocks) with higher education and household income, and were less likely to be smokers (Table 3). Respondents experienced fewer exacerbations requiring emergency department visits or oral corticosteroid dispensings and were less likelyto receive more than 6 canisters of short-acting ß-agonists in 2006. In contrast, respondents were more likely to have asthma outpatient visits, to receive asthma controllers, and to requalify for HEDIS persistent asthma in 2007.
Of 2751 respondents to the baseline survey, 799 (29.0%) completed all 4 surveys. A total of 455 (16.5%) completed 3 surveys, 422 (15.3%) completed 2 surveys, and 1075 (39.1%) completed only the baseline survey.
Survey Persistent Asthma Versus HEDIS Persistent Asthma
A total of 2517 among 2751 respondents (91.5%) had survey persistent asthma on the baseline survey. These 2517 patients met the following persistent asthma criteria: (1) symptoms with or without other criteria (74.7%), (2) medications without qualifying symptoms (24.5%), or (3) exacerbations without symptom or medication criteria (0.8%).
A total of 1764 among 2751 respondents (64.1%) requalified for HEDIS persistent asthma in 2007. Of those who requalified, 97.1% reported survey persistent asthma (Table 4). Patients with survey persistent asthma were significantly more likely to requalify for HEDIS persistent asthma in 2007 than patients without survey persistent asthma (68.0% vs 22.2%, P <.001). However, 805 of 987 patients (81.6%) who did not requalify as having HEDIS persistent asthma in 2007 (but who had qualified in 2006) reported survey persistent asthma in 2007.
Persistent Asthma Versus Medical Utilization