Wen-Chen Tsai, DrPH

 This study investigated the effects of physician continuity, measured as the Continuity of Care Index (COCI) score, on the survival of patients with diabetes, including both pay-for-performance (P4P) participants and nonparticipants.

This was a retrospective, nationwide population-based analysis of 396,838 patients with diabetes, with 198,419 subjects each in the P4P participant and nonparticipant groups, from 1997 to 2009, in Taiwan.

The data presented in this study are secondary data obtained from the 1997 to 2009 National Health Insurance Research Database published by the Taiwan National Health Research Institute. Survival status and physician continuity were the dependent variables. Multiple regression analysis was used to examine the factors related to physician continuity among patients with diabetes. The Cox proportional hazard model was used to explore the related factors that affected the survival status of the patients with diabetes.

After controlling for the other related factors, the COCI score of the P4P participants was 0.227 higher than that of the nonparticipants (P <.05). Compared with patients with a low COCI score (≤50%), the hazard ratio (HR) of mortality of patients with a high COCI score (>50%) was 0.47 (95% confidence interval [CI], 0.46-0.48). Compared with nonparticipants, the HR of mortality of P4P participants was 0.43 (95% CI, 0.41-0.44).

Patients with diabetes with higher physician continuity had a lower HR of mortality. P4P participants had higher physician continuity and a lower HR of mortality. 

		Diabetes pay-for-performance programs had higher physician continuity of care.

		Patients with diabetes with higher physician continuity had lower mortality. 

		For other chronic diseases, such as hypertension or obesity, pay-for-performance programs can be applied and might also increase patients’ physician continuity and survival.

Diabetes is a common chronic metabolic disease with increasing prevalence.

 The strategies to improve diabetes care include optimizing the behavior of health providers, supporting patient behavioral adaptations, and changing the system of care.

 With the increasing number of patients with diabetes, the provision of high-quality and cost-effective care for these patients has become an important but difficult task for healthcare providers.

 The healthcare systems of many countries have implemented pay-for-performance (P4P) programs to improve the quality of care. To improve patient outcomes, a P4P program provides ï¬nancial rewards to healthcare providers who achieve pre-established criteria for treating specific diseases.

In Taiwan, the National Health Insurance (NHI) Administration implemented its diabetes P4P program in 2001. Physicians whose specialties were internal medicine, pediatrics, family medicine, metabolism and endocrinology, cardiology, or nephrology were allowed to voluntarily participate.

 The P4P program provides financial incentives with additional reimbursements, which include increasing physician fees and case management fees to the participating physicians. In this program, quality performance is monitored by 4 indicators—each representing 25% of total achievement&mdash;that include the rates of patients: 1) who completed regular follow-ups (at least 3 visits per year), 2) whose glycated hemoglobin (A1C) was lower than 7%, 3) whose A1C was higher than 9.5%, and 4) whose low-density lipoprotein (LDL) was higher than 130 mg/dL. The achievement rate of each indicator was then summed and became the final achievement grade. Physicians were ranked according to this final achievement. Physicians can receive additional bonuses if they are ranked in the top 25% of their peers.

 Under this program, physicians are required to keep their P4P participants in follow-up at their clinic. If the P4P participants change doctors, the physician bonuses will be decreased or cancelled.

Taiwan’s NHI program has no strict referral system; patients can go to any hospital or see any doctor of any subspecialty. However, changing physicians frequently seems to result in adverse outcomes. McAlister et al found that the mortality risk of patients with heart failure was lower among those who visited familiar physicians.

 Younge et al found that in patients with diabetes, a lower modified Continuity of Care Index (COCI) score was associated with poorer A1C control and a higher modified COCI score was associated with better LDL control.

 Physician continuity is also a factor related to lower healthcare costs. De Maeseneer et al found that patients visiting the same family physician had lower total medical costs.

 In a diabetes P4P program, there should be many factors, including physician continuity, that would have an effect on the clinical outcomes and survival of treated patients; however, to our knowledge, no papers have discussed this topic until now.

This study was designed to investigate factors that influence the participation of patients with diabetes in the P4P program. The objectives of the study are to explore the differences in physician continuity of care and survival between diabetes P4P participants and nonparticipants and to investigate the related factors influencing physician continuity of care and survival among diabetes P4P participants.

The data presented in this retrospective study are secondary data obtained from the 1997 to 2009 NHI Research Database published by the National Health Research Institute. The study population included only patients newly diagnosed with type 2 diabetes between 2001 and 2009. Such a patient was defined as one hospitalized a minimum of 1 time or who was diagnosed with diabetes (

International Classification of Diseases, Ninth Revision, Clinical Modification 

] code 250.x or A181) a minimum of 3 times at outpatient visits within 365 consecutive days (including both the primary and secondary diagnosis).

code 648.0 or 648.8), neonatal diabetes (

 code 775.1), or impaired glucose tolerance (

 code 790.2) were excluded. A total of 1,179,862 patients were included in the study. The medical records of the follow-up outpatient visits of patients who had participated in the P4P program were reviewed and the specific treatment code E4 (P4P program for diabetes) was used as an indicator for these patients. Patients with diabetes who did not participate in the program for a minimum of half a year (26 weeks) were also excluded from the study.

In addition, personal factors and hospital policy could affect the participation of patients with diabetes in the P4P program, and thus, selection bias might occur.

 We adopted the following method to reduce selection bias between patients with diabetes who had or had not participated in the program. This method had been widely used in studies based on the Taiwan NHI database.

 The propensity score-matching method was used to collect a total of 396,830 research samples in 1:1 matching for further analysis based on personal characteristics (ie, gender and age), income (ie, monthly salary), severity of comorbidity (ie, Charlson Comorbidity Index [CCI] score

), severity of diabetes (Diabetes Complications Severity Index [DCSI] score

), and the characteristics of the healthcare organizations (ie, accreditation level and ownership).

Definitions of Variables and Method of Measurement

Two dependent variables were included in the study. The first was the survival status of the patients. Based on death certificate records, insurance withdrawal dates are the same as death dates. Taiwan’s NHI is a compulsory single-payer program and there are only 3 conditions for people being withdrawn from NHI coverage: those who have been jailed for more than 2 months, have been legally missing for more than 6 months, or have died. Death was defined as being withdrawn from the NHI coverage within 30 days of hospital admission; this definition of mortality has been widely used in research based on Taiwan’s NHI data.

The second variable was physician continuity of care, which was measured as the COCI score.

 This index measures the distribution of clinical visits between physicians; a value between 0 and 1 was assigned to each patient. The closer the value was to 1, the higher the degree of continuity of care; a COCI score of 1 suggested that the same physician was seen by the patient at each outpatient visit. The index offered the advantage of being able to consider multiple physicians; the equation for the index is given below:

The independent variables consisted of 5 categories. The first was the personal characteristics of the research patients, including gender, age, and monthly salary. The second was the environmental factor. We used the degree of urbanization, categorized into 7 levels, to reflect the characteristics of the residential area. Level 1 indicated the highest degree of urbanization and level 7 represented the lowest.

 The third variable was health condition, including the severity of comorbidities and of the complications of diabetes. Severity of comorbidities was determined based on Deyo’s methodology, in which the primary and secondary 

 diagnosis codes of the patients were converted into weighted numerical scores (using 1, 2, 3, and 6 points, respectively) and the weighted scores were summed to become the CCI score.

 The diabetes-related chronic complications of the CCI were not included in the CCI score to avoid duplication of the diseases already included in the DCSI score.

 The severity of complications of diabetes was determined according to the DCSI published by Young et al.

 This methodology includes the following complications of diabetes: diabetic retinopathy, nephropathy, neuropathy, cerebrovascular disease, cardiovascular diseases, peripheral vascular diseases, and endocrine complications. The primary and secondary 

 diagnosis codes of these complications were then converted into numbers, which were summed and became the DCSI score (ranging from 0 [low] to 13 [high]). The fourth variable was characteristics of the primary physicians, represented by the physicians’ annual service volume: high (>75%), medium (25%-75%), and low (<25%), using the quartile method before being subjected to analysis. The fifth was characteristics of the primary healthcare organizations, including their level and ownership.

SAS version 9.3 (SAS Institute, Cary, North Carolina) was used to process and analyze the data. The research patients were divided into those who had and had not participated in the P4P program. The differences in each independent variable of the 2 groups are presented using percentages, mean, and standard deviation. Moreover, the 

 test was used to analyze whether there were significant differences in personal characteristics, health conditions, environmental factors, characteristics of primary physicians, and characteristics of major healthcare organizations between the 2 groups. Multiple regression analysis was used to examine the related factors of physician continuity of care in patients with diabetes. The Cox proportional hazard model was used to explore the related factors that affected the survival status of the patients with diabetes. This study was approved by the China Medical University Institutional Review Board.

A total of 396,838 subjects were included in this study, with 198,419 subjects in each group. After matching, all variables, including gender, age, monthly salary, CCI score, DCSI score, and level and ownership of healthcare organizations, revealed no significant differences between the 2 groups (

We divided the patients into subgroups based on gender, age, monthly salary, level of residential urbanization, CCI score, DCSI score, physician’s annual service volume, level and ownership of healthcare organizations, and diabetes duration. In each subgroup, the mean COCI score of the P4P participants (0.57 to 0.67) was significantly higher than that of the nonparticipants (0.17 to 0.50), meaning that P4P participants had higher physician continuity. Detailed data are shown in 

In the multiple regression analysis, controlling for the other related factors, the COCI score of the P4P participants was 0.227 higher than that of the nonparticipants (

 <.05). After controlling for other factors, the trend indicated that patients with diabetes who were treated by physicians with a higher annual service volume had higher COCI scores. Compared with patients treated by physicians with a low annual service volume, the COCI score of patients treated by physicians with a medium or high annual service volume was higher by 0.096 (

<.05), respectively. Compared with female patients, the COCI score of male patients was lower by 0.010 (

<.05). Patients with diabetes living in urbanization level 6 and 7 areas had lower COCI scores (0.009 lower; 

 <.05). Patients with higher CCI or DCSI scores tended to have lower COCI scores. Compared with the patients whose CCI scores were 0 to 1, patients with a higher CCI score had a COCI score 0.020 to 0.085 lower (

<.05). Compared with patients whose DCSI was 0 to 1, the COCI scores of patients with DCSI 2 or greater than or equal to 3 were 0.030 (

<.05) lower, respectively. In addition, compared with patients treated at medical centers, patients who were treated at clinics had higher COCI scores (0.062 higher; 

<.05). The COCI scores of patients treated at nonpublic hospitals were 0.003 lower (

 <.05) than those of patients treated at public hospitals. Patients with a longer diabetes duration tended to have lower COCI scores; compared with those whose diabetes duration was less than 3 years, patients with a longer diabetes duration had a COCI score 0.012 to 0.015 lower (

 <.05). Details on the data are shown in 

Compared with patients with low COCI scores, the hazard ratio (HR) of mortality of patients with high COCI scores was 0.47 and the 95% confidence interval (CI) was between 0.46 and 0.48. Compared with P4P nonparticipants, the HR of mortality of P4P participants was 0.43 (95% CI, 0.41-0.44). Male patients showed a higher HR of mortality of 1.75 (95% CI, 1.71-1.80) compared with female patients. All of the following categories of patients tended to have lower HRs of mortality: those who were younger, had higher salaries, lived in areas of higher urbanization, or were treated by physicians with a higher annual service volume. The HRs of mortality of patients who were treated at regional hospitals, district hospitals, and clinics were 0.90 (95% CI, 0.87-0.93), 0.81 (95% CI, 0.78-0.84), and 0.58 (95% CI, 0.56-0.60), respectively, compared with patients who were treated at medical centers. The HR of mortality of patients who were treated at nonpublic hospitals was 1.16 (95% CI, 1.13-1.19) compared with that of patients treated at public hospitals. Compared with patients whose CCI score was 0 to 1, those higher CCI scores had high HRs of mortality, 1.10 to 2.12 (

 <.05). Compared with patients whose DCSI was 0 to 1, the HRs of mortality of patients with DCSI 2 or ≥3 were 1.47 (95% CI, 1.43-1.52) and 1.65 (95% CI, 1.60-1.71), respectively. Detailed data are shown in 

The survival curve of patients with diabetes is shown in the 

. The cumulative survival rate was highest in P4P participants with high COCI scores, followed by P4P nonparticipants with high COCI scores, P4P participants with low COCI scores, and P4P nonparticipants with low COCI scores. For either P4P participants or P4P nonparticipants, the cumulative survival rate of patients with high COCI scores was greater than that of patients with low COCI scores. In both high COCI and low COCI groups, the cumulative survival rate of P4P participants was higher than that of P4P nonparticipants (Figure).

In the Taiwanese P4P program, additional bonuses are given to physicians if their performance quality is ranked in the top quarter of their peers or if they maintain regular follow-up of their patients at their clinics. To achieve these goals, physicians should try to retain their P4P participants by providing good service, maintaining a high quality of diabetes treatment, and lowering the related treatment complications of the patients. If the patients are followed by the same physician, with regular serial laboratory and clinical records, the physician can more easily check each patient’s general condition and modify treatment methods as necessary, which can subsequently improve treatment quality. With improved treatment quality and outcome, patients are more likely to trust their doctors and are less likely to change physicians.

Mainous et al found that better trust between physicians and patients was associated with higher physician continuity.

 This then becomes a virtuous cycle in which physicians can keep patients by improving treatment outcome and patients tend to consult with the same doctors because of the stable blood sugar control they experience. This might be the main reason that the P4P participants had significantly higher physician continuity than the nonparticipants.

Some patients suffered not only from diabetes, but also other chronic diseases, such as hypertension, hyperlipidemia, coronary artery disease, and chronic kidney disease. These patients had higher CCI scores and were more likely to take multiple drugs to control their diseases. In addition, some patients suffered from diabetic complications, such as diabetic retinopathy, diabetic nephropathy, diabetic neuropathy, or diabetic foot pain; additional medication or even surgery may be indicated for patients with a higher DCSI score. Because of their more complicated medical conditions and possible drug interactions, patients with higher CCI or DCSI scores may be more likely to experience poor diabetes control. In such situations, patients might seek other physicians to get second opinions or better treatment. Whenever patients believe that their diseases are not well controlled or treated, they can easily consult other doctors without referral because Taiwan has no strict referral system. This might be why patients with diabetes with higher CCI or DCSI scores—both P4P participants and nonparticipants&mdash;had lower physician continuity.

In Taiwan, most patients prefer well-known doctors who usually have a higher service volume. This situation exists generally in Taiwan, not just in diabetes care: physicians with the best reputations attract more patients, then have higher service volumes. It is believed that these physicians have more clinical experience, better service, and better treatment outcomes. It is possible that treatment by these physicians is a guarantee of professional treatment and complete cure, so they are happy to spend much more time or pay higher service fees to consult them. These may be the reasons that both P4P participants and P4P nonparticipants who were treated by physicians with high annual service volumes had higher physician continuity.

Most patients with stable diabetes usually need just regular checkups and drug prescriptions. Family physicians in clinics can provide better healthcare accessibility and availability, so it is very convenient for such patients to be treated and followed up there. If patients’ blood sugar levels become unstable, however, they may seek specialists, who they believe to be more professional, at medical centers or regional hospitals. Once their blood sugar stabilizes, they may again prefer to be treated and followed up at clinics because of convenience and shorter waiting time. In addition, stable patients with diabetes treated at clinics usually have fewer complications, such as emergency department (ED) visits, and, thus, the patients are willing to be treated at clinics.

 These may be the reasons that patients who were treated at clinics had higher physician continuity.

McAlister et al found that high physician continuity could reduce adverse outcomes among patients with heart failure.

 High physician continuity has been associated with lower likelihoods of admission to the ED

 and with having guideline-consistent care.

 These factors should have similar effects on patients with diabetes. Patients with high COCI scores were generally followed up by a single doctor, and in these cases, physicians were familiar with the patients’ general condition and could provide more effective and efficient treatment. These might be the reasons that patients with high COCI scores had higher survival.

Our data show that the HR of mortality increased as patients became elderly. People of advanced age usually have a higher likelihood of suffering from cancer or chronic diseases. Even upper respiratory infection could cause the death of an elderly person due to complications. Associated diseases or complications and poor drug adherence may result in poor diabetes control among senior patients.

 These factors might lead to a higher mortality rate among the elderly.

This study showed the HR of mortality was higher in patients with lower monthly income. Social gradients and the resultant healthcare inequalities are the main problems in the US healthcare system

 and in other countries, including Taiwan. Multiple factors influence this situation, including patient—physician communication, culture, social support and integration, and accessibility of healthy foods and places to exercise.

 For these reasons, patients with a lower monthly salary might have an inferior lifestyle, poor control of disease, and higher risk of mortality.

Yu et al found that patients with diabetes with higher CCI or DCSI scores had a higher HR of ED visits for hypoglycemia.

 Further, Young et al found that a higher DCSI score indicated a higher risk of hospitalization and mortality among patients with diabetes.

 Some patients with diabetes may suffer from other chronic diseases and subsequently have higher CCI scores; additionally, patients with higher DCSI scores have variable diabetic-related complications and may experience poor blood sugar control. Either a high CCI or DCSI score may result in difficulty in diabetes control or more complications, leading to increased risk of mortality among such patients.

Yu et al found that the overloading of physicians might worsen treatment quality.

 Physicians with an excessively high service volume may be too busy to provide adequate patient education and treatment integration, which may lower the quality of care, clinical outcomes, and survival, thus possibly indicating why patients treated by physicians with high annual service volumes had higher HRs of mortality.

Although being treated at a clinic is associated with higher physician continuity, any patient—especially with multiple diseases&mdash;can directly visit doctors in medical centers and pay low co-payments under Taiwan’s health insurance system. In addition, patients may be referred to medical centers due to multiple chronic diseases or diabetic complications. It is likely that patients treated at medical centers have higher CCI or DCSI scores, and these patients may have more comorbidities and complications and a higher risk of mortality.

First, the database contained claims data only, not laboratory results. It was impossible to confirm the relationship between diabetes severity and laboratory results. Second, many environmental factors may affect physician continuity and the survival of patients with diabetes; urbanization is only 1 of these factors. Third, the database did not have data on lifestyle, occupation, and family history. The effect of these factors on the patients could not be evaluated.

Articles

Patients with diabetes who participate in a pay-for-performance program had higher continuity of care index (COCI) scores, and those with high COCI scores had higher survival rates.

Patients With Diabetes in Pay-for-Performance Programs Have Better Physician Continuity of Care and Survival

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 (

 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.

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.

Factors Related to Continuing Care and Interruption of P4P Program Participation in Patients With Diabetes

	To improve the quality of care, multidisciplinary team (MDT) care was implemented in Taiwan. This study examined the relationship between MDT care and emergency department (ED) visits for lung cancer patients.

	A retrospective cohort study with MDT care participants and matched a double number of control group of non-participants was followed.

	In this study, 22,817 patients with newly diagnosed lung cancer were recruited from 2005 to 2007 in Taiwan. Matching based on the propensity of receiving MDT care was used. A total of 8172 patients were observed in this study. A c2, ANOVA, logistic regression, and Poisson regression were used to elucidate the effects of MDT care.

	The lung cancer patients participating in MDT had lower risk to visit an ED (OR = 0.89; 95% CI, 0.80-0.98), and the incidence rate ratio decreased by 11% (95% CI, —0.15 to –0.07). Gender, monthly salary, urbanization of the residence area, comorbid conditions, catastrophic illness/injury, treatment method, number of outpatient visits, length of stay,

	hospital ownership, level of hospital, and the age of the patient’s physician were all significantly related to the frequency of ED visits (P <.05).

	The frequency of ED visits of patients with MDT care was lower than that of those without it. The patients with MDT received enhanced care.

Multidisciplinary team care can improve the effectiveness of care for lung cancer 

The incidence rate ratio of emergency department (ED) visits decreased 11% for lung 

cancer patients participating in MDT care.

The primary cause of ED visits was fever for both the MDT participants (25.46%) and 

Worldwide, lung cancer is the most common cancer 

in terms of both incidence and mortality. In 

2012, there were 1.8 million new cases and 1.59 

has been the leading cause of cancer death in Taiwan 

diagnosis and treatment of lung cancer, both the incidence 

and mortality rate of lung cancer have increased in recent 

years. Formal multidisciplinary team (MDT) care has been 

widely promoted worldwide to improve coordination, communication, 

and decision making in cancer management.

The Taiwan bureau of National Health Insurance has implemented 

“multidisciplinary team care for cancer patients” 

since April 2003 to enhance the quality of cancer diagnosis 

and treatment. The bureau emphasizes an MDT approach 

that provides a complete cancer treatment plan for patients. 

MDT care goes beyond such conventional treatments for

lung cancer as surgical excision, radiation therapy, and chemotherapy. 

The MDT members can include related clinical 

physicians, nursing staff, a psychological consultant, a social 

worker, and a case manager to discuss a dedicated treatment 

plan and to integrate all treatments and care. Therefore, 

the patient with MDT care should benefit from stable and 

continuous care that includes regular outpatient visits and 

inpatient treatment, all arranged and coordinated through 

the case manager. The Bureau of National Health Insurance 

(NHI) paid additional fees to physicians to make MDT care 

The MDT approach has been used for years in numerous 

countries. Studies from the United States, Germany, the 

Impact of multidisciplinary team care on reducing utilization of emergency department visits for patients with lung cancer.

Wen-Chen Tsai, DrPH

Articles

Patients With Diabetes in Pay-for-Performance Programs Have Better Physician Continuity of Care and Survival

Factors Related to Continuing Care and Interruption of P4P Program Participation in Patients With Diabetes

Effects of Multidisciplinary Team Care on Utilization of Emergency Care for Patients With Lung Cancer