Yi-Jing Sheen, MD, MHA, Li-Ting Chiu, MHA

To examine factors that influenced continuing care participation in patients with diabetes and factors contributing to interrupted participation for patients with diabetes enrolled in a diabetes pay-for-performance (P4P) program in Taiwan.

Data were obtained from Taiwan’s National Health Insurance Research Database on patients with a new confirmed diagnosis of type 2 diabetes during 2001 to 2008, selected as 1:1 propensity score-matched P4P program enrollees and nonenrollees (totaling 396,830). Logistic regression was performed to analyze factors associated with continuing care participation and with interrupted P4P program participation after enrollment.

Among the patients with diabetes, P4P program enrollees were 4.27 times (95% CI, 4.19-4.36) more likely to participate in continuing care than nonenrollees. Factors affecting the participation of patients with diabetes in continuing care included P4P program enrollment status, personal characteristics, health status, characteristics of the main physician, and characteristics of the main healthcare organization. Interruption of P4P program participation occurred in 78,759 (44.33%) of the enrolled patients with diabetes and was correlated with male gender, younger age (<35 years), residence in areas of highest urbanization, greater severity of diabetes complications, presence of catastrophic illness/injury, high service volume at the site of the main physician, older age (≥55 years) of the main physician, having a regional or private hospital as the main healthcare organization, and change of physician.

Taiwan’s diabetes P4P program increased continuing care participation in patients with diabetes. The rate of interruption of P4P program participation among enrolled patients with diabetes, at 44.33%, should be a focus of improvement for Taiwan’s health authorities.

	This study examined factors associated with continuing care participation in patients with diabetes and with interrupted participation for those patients enrolled in a diabetes pay-for-performance (P4P) program.

		Taiwan’s P4P program increased the rate of continuing care in patients with diabetes.

		Factors that correlated with the participation of patients with diabetes in continuing care included the patient’s P4P program enrollment status, personal characteristics, health status, characteristics of the main physician, and characteristics of the main healthcare organization.

		Factors associated with interrupted participation by patients with diabetes in the P4P program after enrollment included male gender, younger age (<35 years), residence in areas of the highest urbanization level, greater severity of diabetes complications, presence of catastrophic illness or injury, high service volume at the site of the main physician, older age (≥55 years) of the main physician, having a regional or private hospital as the main healthcare organization, and change of physician.

In 2014, an estimated 415 million individuals worldwide had diabetes, and the number of individuals with diabetes is expected to rise to 642 million by 2040.

 Previous studies have shown the challenges of diabetes prevention and management,

 but better continuity of care has been associated with improved medication compliance

 and healthcare expenses for patients with diabetes.

Pay-for-performance (P4P) is a payment scheme that rewards healthcare providers for providing high-quality continuing care services.

 In many countries—such as the United States, Australia, Germany, and the United Kingdom&mdash;P4P programs are a priority policy for promoting more efficient use of healthcare resources and enhancing the quality of care.

In Taiwan, 7% of the population (1,631,599 individuals) had diabetes as of 2012, which accounts for 3.8% of the National Health Insurance program’s total annual healthcare expenditure.

 To improve the prevention and treatment of this disease, Taiwan launched a diabetes P4P program in November 2001. As part of this program, a team of care providers, consisting of physicians, nurses, nutritionists, and other healthcare professionals work together to provide examination, testing, health education, and follow-up services in an effort to reduce the occurrence of diabetic complications and comorbidities.

 Healthcare organizations participating in the program must perform specific diagnosis and management tasks, including medical history, physical examination, laboratory evaluation, evaluation of the management plan, and diabetes self-management education. Patients who are enrolled in the diabetes P4P program must undergo a complete annual evaluation of their disease. If healthcare services have been provided as required by the program, the healthcare organization will receive a bonus payment: a value-added physician examination fee and a case management fee. For Taiwan’s diabetes P4P program, the amount of the bonus payment is calculated using a point system, and the case management fee includes: 400 points awarded for the initial physician visit (once per patient), 200 points for each follow-up visit (once every 3 months), and 800 points for the annual evaluation (once per year),

 where 1 point is worth around 1 New Taiwan Dollar (NTD) (30 NTD = US$1). In 2009, 27.56% (214,340) of Taiwan’s patients with diabetes were enrolled in the program.

Previous assessments of Taiwan’s diabetes P4P program have found it to effectively increase clinical guideline adherence

 and patient satisfaction with the quality of care,

 as well as decrease inpatient care utilization.

 In this study, we used data from the National Health Insurance database to examine factors that influence continuing care participation in patients with diabetes who either are or are not enrolled in the P4P program, and factors that affect whether interrupted participation in the P4P program occurs in patients with diabetes who are enrolled in the program. Both Taiwan and the United States provide doctors with financial incentives to enhance medical quality, and some payments are based on quality indicators. However, P4P in Taiwan is implemented by a single public insurer (National Health Insurance), whereas P4P in the United States is practiced under multiple medical insurance systems. The study results could be a policy reference for comparisons among different health insurance systems.

Previous studies have adopted variables such as gender, age, monthly salary, comorbidities,

 Diabetes Complications Severity Index (DCSI) score, and hospital accreditation level

 when evaluating diabetes P4P programs. On the basis of logical inference, we searched for possible variables that might account for patients joining or withdrawing from a diabetes P4P program; the topic has rarely been studied.

In this retrospective cohort study, analysis was performed with secondary data obtained from the National Health Insurance Research Database maintained by Taiwan’s National Health Research Institutes. The study population consisted of all patients with a confirmed diagnosis of type 2 diabetes from 2001 through 2008. Patients with diabetes were defined as individuals with 1 hospitalization, or 3 or more outpatient visits within 365 days, in which the primary or secondary diagnosis was diabetes (

International Classification of Diseases, Ninth Revision, Clinical Modification 

 code 648.0), or diabetes that is gestational (648.8) or neonatal (775.1), or had abnormal glucose tolerance (790.2) were excluded from the study. Patients with diabetes whose outpatient records had ever been designated with the specific treatment code “E4” (for the diabetes P4P program) were defined as P4P program enrollees (N = 198,420). All study subjects were followed until the end of 2009.

Propensity score matching was performed on the basis of personal characteristics (gender, age, monthly salary, and residence urbanization level); health status (comorbidity, severity of diabetes complications, and presence or absence of catastrophic illness or injury); and characteristics of the healthcare organization (level and ownership type) in order to match P4P enrollees 1:1 with nonenrollees among patients with diabetes. This resulted in a sample of 396,830 patients for analysis. For the analysis of factors related to interrupted participation in the diabetes P4P program after enrollment, we excluded enrollees, totaling 20,744, who did not reach the time point for their annual evaluation (29 full weeks after enrollment), leaving 177,676 enrollees for the analysis. To encourage medical teams to improve their monitoring of and continual care for patients, the National Health Insurance Administration in Taiwan has established payment regulations for its diabetes P4P program. Patients with diabetes who have been in the P4P program for 29 weeks can participate in yearly evaluations, and the doctor can receive the annual case management fee for each patient.

The dependent variables examined in this study included whether participation in the diabetes P4P program was interrupted and whether continuing care participation was maintained. The independent variables analyzed included personal characteristics

 characteristics of the main physician seen (age and annual service volume), and characteristics of the main healthcare organization utilized. The National Health Insurance Administration in Taiwan has identified 30 types of severe illness or injury as catastrophic illnesses or injuries (eg, malignant neoplasm, type 1 diabetes, chronic renal failure, cerebrovascular disease, rare disease).

Further details on the variables are as follows: 1) continuing care participation was defined as having at least 1 diabetes-related physician visit every 3 months and at least 4 such visits per year following a confirmed diabetes diagnosis for patients not enrolled in the P4P program, or following P4P program enrollment for enrollees. Otherwise, patients were considered to lack continuing care participation. 2) Uninterrupted diabetes P4P program participation was defined as having regular diabetes visits during the year following P4P program enrollment, and then undergoing the annual evaluation of diabetes disease (prescription code P1409C). Enrolled patients who failed to complete the first annual diabetes evaluation were considered to have interrupted participation in the diabetes P4P program. 3) Monthly salaries were taken to be the monthly salary amounts used in the determination of National Health Insurance premiums. 4) The urbanization level of the residence area was designated as 1 of 7 levels, with level 1 corresponding to the highest level of urbanization and level 7 to the lowest. 5) Comorbidity was assessed using the Deyo modification of the Charlson comorbidity score. Each patient’s 

 primary and secondary diagnosis codes were converted to weighted numerical scores, which were then summed to give the patient’s Charlson comorbidity index (CCI).

6) The severity of diabetes complications was assessed using the categories of diabetes complications described by Young et al (retinopathy, nephropathy, neuropathy, stroke, cardiovascular disease, peripheral vascular disease, and metabolic complications). Each patient’s 

 primary and secondary diagnosis codes were converted to weighted numerical scores, which were then summed to give the patient’s DCSI.

 7) Physician service volume was computed as the annual service volume of the patient’s main physician, categorized by the quartile method as high (≥75%), medium (≥25% and <75%), or low (<25%). 8) The characteristics of the main healthcare organization utilized were classified in terms of its level and ownership type. 9) Low-income household status was defined as belonging to a household in which the average monthly income per person falls below the lowest living index, which is 60% of the living expenditure per person in the previous year in the household’s local area.

This study was approved by the Institutional Review Board of China Medical University and Hospital (IRB No. 20130326C).

First, descriptive statistics were used to examine the distribution of different variables—personal characteristics, health status, characteristics of the main physician, characteristics of the main healthcare organization, and continuing care participation&mdash;in the study participants, who were distinguished by whether they were enrolled in the P4P program and whether interruption occurred in their participation in the P4P program after enrollment. The distributions were expressed as percentages and means.

 test were used to examine each variable’s association with continuing care participation in diabetes P4P program enrollees and nonenrollees, as well as association with interrupted P4P program participation in the enrollees. Logistic regression analysis was performed to examine factors that influenced continuing care participation in patients with diabetes.

Finally, logistic regression was employed to examine factors that influenced whether interruption occurred in the participation of patients with diabetes in the P4P program after enrollment. In this study, all statistical analyses were performed using SAS 9.3 software (SAS Institute, Cary, North Carolina) for Windows. A 

value less than .05 was considered statistically significant.

Among the patients with diabetes analyzed in this study, the P4P program enrollees and the propensity score—matched nonenrollees were not significantly different in any of the matched variables, as shown in 

. The majority of the program enrollees participated in continuing care, defined as having at least 1 diabetes-related physician visit every 3 months (71.82%, vs 27.67% who did not), as shown in 

. With respect to personal characteristics, all patients with diabetes characterized by female gender (49.99%), aged 35 to 64 years (50.37%-52.35%), a monthly salary of NTD17,281-22,800 (50.60%), and residence in urbanization level 4 or 5 areas (50.77%) had higher rates of continuing care participation. As for health status, a CCI of 2 (60.19%), a DCSI of 1 (65.13%), and the absence of catastrophic illness or injury (50.88%) corresponded to higher rates of continuing care participation in the all patients with diabetes. Higher rates of continuing care were also observed in patients whose main physicians were aged 45 to 54 years (63.86%) or had a high service volume (70.67%), and in patients whose main healthcare organization was a district hospital (50.63%), a clinic (50.09%), or a public hospital (50.53%).

Factors Affecting Continuing Care Participation in Patients With Diabetes

Logistic regression analysis revealed that patients with diabetes who are enrolled in the P4P program were more likely to participate in continuing care (having at least 1 diabetes-related physician visit every 3 months) than those not enrolled in the program by a factor of 4.27 (95% CI, 4.19-4.36), as shown in 

. Increased odds of continuing care participation were associated with all patient characteristics of female gender, aged 35 to 74 years (odds ratio [OR], 1.05-1.40), and residence in urbanization level 2 or 3 areas (OR, 1.07). With respect to health status, any patients with diabetes with a CCI of 2 (OR, 1.59), with a DCSI of 1 (OR, 1.58), or without catastrophic illness or injury were more likely to participate in continuing care. As for physician and health organization characteristics, higher odds of continuing care participation were found for any patients with diabetes whose care was provided mainly by a physician aged 35 to 44 years (OR, 1.15) or with a high service volume (OR, 3.01), and mainly by a clinic (OR, 1.12) or a public hospital. In particular, physician service volume was directly correlated with the odds of continuing care participation for all patients with diabetes.

Comparison of Characteristics Between Patients With and Without Interruption of Diabetes P4P Program Participation After Enrollment

Of the patients with diabetes who were enrolled in the diabetes P4P program, 78,759 (44.33%) had interrupted participation in the program, as seen in 

. With respect to personal characteristics, higher proportions of enrollees who were male (45.61%), were aged under 35 years (52.35%), had a monthly salary of NTD22,801 to NTD28,800 (46.44%), or resided in urbanization level 1 areas (46.41%) had an interruption of program participation. Among the health status characteristics, a CCI ≥10 (47.65%), a DCSI ≥3 (50.09%), and the presence of catastrophic illness or injury (47.31%) corresponded to higher rates of interrupted program participation. Interrupted program participation also occurred at higher rates in enrollees whose main physician was aged under 35 years (48.60%) or had a high service volume (47.68%), whose main healthcare organization was a regional hospital (47.24%), and who had a change of physician (72.74%).

Factors Associated With Interrupted Diabetes P4P Program Participation in Enrolled Patients With Diabetes

Factors related to interruption of diabetes P4P program participation in enrolled patients with diabetes were analyzed by logistic regression, with the results shown in Table 4. Personal characteristics of the patients with diabetes that were associated with a greater likelihood of interrupted program participation were male (OR, 1.14), aged under 35 years, had a monthly salary of NTD ≤28,800, and residence in urbanization level 1 areas. With respect to health status, enrollees with a DCSI ≥3 (OR, 1.26) or with catastrophic illness or injury (OR, 1.24) were more likely to have an interruption of program participation. After we controlled for all relevant variables in the analysis model, the results changed so for enrollees whose main physician was 55 years or older, there were increased odds of interrupted program participation (OR, 1.19; 95% CI, 1.14-1.25); additional associated factors included having a high service volume (OR, 1.56), having a regional hospital (OR, 1.22) or a private hospital (OR, 1.02) as the main healthcare organization, and having changed physicians (OR, 7.10). In particular, there was a direct correlation between physician service volume and the odds of interrupted diabetes P4P program participation in enrolled patients with diabetes.

In this study, we showed that patients with diabetes who were enrolled in Taiwan’s diabetes P4P program were more likely to engage in continuing care (ie, have at least 1 diabetes-related physician visit every 3 months) than their nonenrolled counterparts (Table 3). This finding is in agreement with a previous study conducted in Taiwan by Lee et al (2010).

 Those authors found that patients with diabetes in the P4P program had a larger increase in the number of diabetes-specific physician visits after program enrollment (annual average increasing from 3.8 times to 6.4 times) than nonenrolled patients in the same period (from 3.5 to 3.6 times).

One of the factors that has been associated with differences in patients’ continuing care participation is gender. Chang et al (2005) showed that female patients with diabetes were more likely than their male counterparts to take their medicine regularly and practice self-care (exercise, dietary control, and weight control).

 observed a higher number of physician visits for female than male patients with diabetes. Previous research also found differing views on health-related issues between men and women and the greater social and cultural acceptability of women being weak or unhealthy.

 Women with diabetes were also shown to more readily seek consultation for illness in general

 and to have more diabetes-related worries.

 Our results show that, compared with their male counterparts, female patients with diabetes were more likely to participate in continuing care (Table 3) and less likely to have interrupted participation in the diabetes P4P program after enrollment (Table 4).

With respect to patient age, it has been shown that younger patients, with a shorter medical history, were less likely than older patients to have established a long-term, sustained relationship with their medical care provider or team.

 Younger patients also self-reported better health status

 and were less likely to have experienced severe diabetes complications.

 Consistently, we found patients with diabetes aged under 35 years to have poorer continuing care participation (Table 3) and higher odds of interrupted diabetes P4P program participation (Table 4). Aller et al (2013) also showed that patients aged under 35 years and patients with poorer health status experienced less relational continuity of care with their physicians.

As for the effect of economic status, a Brazilian study (2003) found that patients with higher income were more likely to have a continual relationship with a regular physician than those with lower income.

 Our results show that patients with diabetes earning less than or equal to NTD28,800 in monthly salary were more likely to have interrupted participation in the diabetes P4P program than those earning over NTD28,800.

The area of residence may affect continuing care because the fast pace of life and busy work schedules in highly urbanized areas leave patients less time for healthcare-related activities. We observed less continuing care participation (Table 3) and more interruption of diabetes P4P program participation after enrollment (Table 4) in patients with diabetes residing in urbanization level 1 areas. A previous study by Lin et al (2011) examining preventive care utilization in Taiwan found that patients with diabetes in the more urbanized northern area had a lower rate of regular use of preventive services than patients with diabetes in the southern area (36.6% vs 29.5%),

A patient’s health status also influences his or her continuing care. A study in Spain (2013) showed that patients with better health status (both self-rated and based on the declared number of health conditions) were better able to maintain a continuing relationship with their physicians.

 In the present study, we found that patients with diabetes who had poorer health status, indicated by a greater severity of diabetes complications (DCSI ≥3) and the presence of catastrophic illness and injury, were more likely to have interrupted participation in the diabetes P4P program after enrollment (Table 4).

With respect to physician service volume, Katz et al (2003) showed a correlation between greater patient satisfaction with a surgical procedure and a higher number of such procedures performed at the hospital or by the surgeon.

 We found in our study that the higher the physician service volume, the higher the likelihood of continuing care participation (at least 1 diabetes-related physician visit every 3 months) in patients with diabetes (Table 3). Yet, for patients with diabetes enrolled in the diabetes P4P program, the higher the physician service volume, the higher the likelihood of interrupted program participation (Table 4). We infer that there is a group of patients who preferentially seek care from high-volume physicians, but have no intention of maintaining a long-term relationship with them—this idea may form the basis for further research. This present study further analyzed the characteristics of the group of P4P patients who did not continue care from the main physicians with high service volume. With respect to personal characteristics, higher proportions of enrollees who did not have continuing care (80.44%), were male (48.57%), were aged under 35 years (54.03%), were in low-income households (53.11%), or resided in urbanization level 1 areas (50.77%) had an interruption of program participation. Among the health status characteristics, a CCI ≥10 (50.62%), a DCSI ≥3 (53.48%), and the presence of catastrophic illness or injury (52.32%) corresponded to higher rates of interruption from the main physicians with high service volume. Interruption from the P4P program also occurred at higher rates in enrollees whose main healthcare organization was a regional hospital (47.24%), a public hospital (49.60%), or who had a change of physician (80.49%).

The effect of hospital ownership type on diabetes care is related to the fact that public hospitals in Taiwan are overseen by health authorities and are eligible for extra healthcare funding for good performance. It is thus in the interest of public hospitals to more actively promote the P4P program. Consistently, patients with diabetes who sought care at public hospitals were more likely to participate in continuing care (Table 3) and less likely to have interrupted participation in the diabetes P4P program after enrollment (Table 4) than their private hospital counterparts.

Our analysis also revealed a correlation between a change of the main physician and interruption of diabetes P4P program participation in patients with diabetes who are enrolled in such a program. A stable, long-term relationship between a patient and a physician has been found to promote familiarity, trust, and better sharing of information,

 as well as to decrease information asymmetry and increase goal alignment,

 and improve treatment compliance. Previous studies have also associated the length of patient-physician relationships with patients’ trust in their physicians

 and with patients’ satisfaction with the outcomes of care.

This study was a retrospective analysis based on data obtained from the National Health Insurance Database. The use of this secondary database limited the number of variables available for our analysis. The monthly salary, used as a proxy for economic status, does not represent an individual’s entire income. Also, the database did not include information on the study participants’ health beliefs and health behaviors, limiting further analysis in this study.

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Analyzing factors associated with continuing care participation in patients with diabetes and with interrupted participation by patients enrolled in a diabetes pay-for-performance program.

Yi-Jing Sheen, MD, MHA, Li-Ting Chiu, MHA

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