Impacts of pay for performance on the quality of primary care

Assessing Taiwan's pay-for-performance program for diabetes care: a cost-benefit net value approach

Pay-for-Performance (P4P) to better manage chronic conditions has yielded mixed results. A better understanding of the cost and benefit of P4P is needed to improve program assessment. To this end, we assessed the effect of a P4P program using a quasi-experimental intervention and control design. Two different intervention groups were used, one consisting of newly enrolled P4P patients, and another using P4P patients who have been enrolled since the beginning of the study. Patient-level data on clinical indicators, utilization and expenditures, linked with national death registry, were collected for diabetic patients at a large regional hospital in Taiwan between 2007 and 2013. Net value, defined as the value of life years gained minus the cost of care, is calculated and compared for the intervention group of P4P patients with propensity score-matched non-P4P samples. We found that Taiwan's implementation of the P4P program for diabetic care yielded positive net values, ranging from $40,084 USD to $348,717 USD, with higher net values in the continuous enrollment model. Our results suggest that the health benefits from P4P enrollment may require a sufficient time frame to manifest, so a net value approach incorporating future predicted mortality risks may be especially important for studying chronic disease management. Future research on the mechanisms by which the Taiwan P4P program helped improve outcomes could help translate our findings to other clinical contexts.

Does the implementation of an incentive scheme increase adherence to diabetes guidelines? A retrospective cohort study of managed care enrollees

BACKGROUND

A novel incentive scheme based on a joint agreement of a large Swiss health insurance with 56 physician networks was implemented in 2018. This study evaluated the effect of its implementation on adherence to evidence-based guidelines among patients with diabetes in managed care models.

METHODS

We performed a retrospective cohort study, using health care claims data from patients with diabetes enrolled in a managed care plan (2016-2019). Guideline adherence was assessed by four evidence-based performance measures and four hierarchically constructed adherence levels. Generalized multilevel models were used to examine the effect of the incentive scheme on guideline adherence.

RESULTS

A total of 6'273 patients with diabetes were included in this study. The raw descriptive statistics showed minor improvements in guideline adherence after the implementation. After adjusting for underlying patient characteristics and potential differences between physician networks, the likelihood of receiving a test was moderately but consistently higher after the implementation of the incentive scheme for most performance measures, ranging from 18% (albuminuria: OR, 1.18; 95%-CI, 1.05-1.33) to 58% (HDL cholesterol: OR, 1.58; 95%-CI, 1.40-1.78). Full adherence was more likely after implementation of the incentive scheme (OR, 1.37; 95%-CI, 1.20-1.55), whereas level 1 significantly decreased (OR, 0.74; 95%-CI, 0.65 - 0.85). The proportions of the other adherence levels were stable.

CONCLUSION

Incentive schemes including transparency of the achieved performance may be able to improve guideline adherence in patients with diabetes and are promising to increase quality of care in this patient population.

The Cost of Uncontrolled Blood Pressure in Australian General Practice: A Modelling Study Using Electronic Health Records (MedicineInsight)

BACKGROUND

Hypertension is the most common condition seen in Australian general practice. Despite hypertension being amenable to lifestyle modifications and pharmacological treatment, only around half of these patients have controlled blood pressure levels (< 140/90 mmHg), placing them at an increased risk of cardiovascular disease.

OBJECTIVE

We aimed to estimate the health and acute hospitalisation costs of uncontrolled hypertension among patients attending general practice.

METHODS

We used population data and electronic health records from 634,000 patients aged 45-74 years who regularly attended an Australian general practice between 2016 and 2018 (MedicineInsight database). An existing worksheet-based costing model was adapted to calculate the potential cost savings for acute hospitalisation of primary cardiovascular disease events by reducing the risk of a cardiovascular event over the next 5 years through improved systolic blood pressure control. The model estimated the number of expected cardiovascular disease events and associated acute hospital costs under current levels of systolic blood pressure and compared this estimate with the expected number of cardiovascular disease events and costs under different levels of systolic blood pressure control.

RESULTS

The model estimated that across all Australians aged 45-74 years who visit their general practitioner (n = 8.67 million), 261,858 cardiovascular disease events can be expected over the next 5 years at current systolic blood pressure levels (mean 137.8 mmHg, standard deviation = 12.3 mmHg), with a cost of AUD$1813 million (in 2019-20). By reducing the systolic blood pressure of all patients with a systolic blood pressure greater than 139 mmHg to 139 mmHg, 25,845 cardiovascular disease events could be avoided with an associated reduction in acute hospital costs of AUD$179 million. If systolic blood pressure is lowered further to 129 mmHg for all those with systolic blood pressure greater than 129 mmHg, 56,169 cardiovascular disease events could be avoided with potential cost savings of AUD$389 million. Sensitivity analyses indicate that potential cost savings range from AUD$46 million to AUD$1406 million and AUD$117 million to AUD$2009 million for the two scenarios, respectively. Cost savings by practice range from AUD$16,479 for small practices to AUD$82,493 for large practices.

CONCLUSIONS

The aggregate cost effects of poor blood pressure control in primary care are high, but cost implications at the individual practice level are modest. The potential cost savings improve the potential to design cost-effective interventions, but such interventions may be best targeted at a population level rather than at individual practices.

Incentivizing appropriate prescribing in primary care: Development and first results of an electronic health record-based pay-for-performance scheme

OBJECTIVE

Part of the funding of Dutch General Practitioners (GPs) care is based on pay-for-performance, including an incentive for appropriate prescribing according to guidelines in national formularies. Aim of this paper is to describe the development of an indicator and an infrastructure based on prescription data from GP Electronic Health Records (EHR), to assess the level of adherence to formularies and the effects of the pay-for-performance scheme, thereby assessing the usefulness of the infrastructure and the indicator.

METHODS

Adherence to formularies was calculated as the percentage of first prescriptions by the GP for medications that were included in one of the national formularies used by the GP, based on prescription data from EHRs. Adherence scores were collected quarterly for 2018 and 2019 and subsequently sent to health insurance companies for the pay-for-performance scheme. Adherence scores were used to monitor the effect of the pay-for-performance scheme.

RESULTS

75% (2018) and 83% (2019) of all GP practicesparticipated. Adherence to formularies was around 85% or 95%, depending on the formulary used. Adherence improved significantly, especially for practices that scored lowest in 2018.

DISCUSSION

We found high levels of adherence to national formularies, with small improvements after one year. The infrastructure will be used to further stimulate formulary-based prescribing by implementing more actionable and relevant indicators on adherence scores for GPs.

Strategies to implement SARS-CoV-2 point-of-care testing into primary care settings: a qualitative secondary analysis guided by the Behaviour Change Wheel

BACKGROUND

The purpose of this study is to develop a theory-driven understanding of the barriers and facilitators underpinning physicians' attitudes and capabilities to implementing SARS-CoV-2 point-of-care (POC) testing into primary care practices.

METHODS

We used a secondary qualitative analysis approach to re-analyse data from a qualitative, interview study of 22 primary care physicians from 21 primary care practices across three regions in England. We followed the three-step method based on the Behaviour Change Wheel to identify the barriers to implementing SARS-CoV-2 POC testing and identified strategies to address these challenges.

RESULTS

Several factors underpinned primary care physicians' attitudes and capabilities to implement SARS-CoV-2 POC testing into practice. First, limited knowledge of the SARS-CoV-2 POC testing landscape and a demanding workload affected physicians' willingness to use the tests. Second, there was scepticism about the insufficient evidence pertaining to the clinical efficacy and utility of POC tests, which affected physicians' confidence in the accuracy of tests. Third, physicians would adopt POC tests if they were prescribed and recommended by authorities. Fourth, physicians required professional education and training to increase their confidence in using POC tests but also suggested that healthcare assistants should administer the tests. Fifth, physicians expressed concerns about their limited workload capacity and that extra resources are needed to accommodate any anticipated changes. Sixth, information sharing across practices shaped perceptions of POC tests and the quality of information influenced physician perceptions. Seventh, financial incentives could motivate physicians and were also needed to cover the associated costs of testing. Eighth, physicians were worried that society will view primary care as an alternative to community testing centres, which would change perceptions around their professional identity. Ninth, physicians' perception of assurance/risk influenced their willingness to use POC testing if it could help identify infectious individuals, but they were also concerned about the risk of occupational exposure and potentially losing staff members who would need to self-isolate.

CONCLUSIONS

Improving primary care physicians' knowledgebase of SARS-CoV-2 POC tests, introducing policies to embed testing into practice, and providing resources to meet the anticipated demands of testing are critical to implementing testing into practice.

The effects of structure, process and outcome incentives on primary care referrals to a national prevention programme

Despite widespread use, evidence is sparse on whether financial incentives in healthcare should be linked to structure, process or outcome. We examine the impact of different incentive types on the quantity and effectiveness of referrals made by general practices to a new national prevention programme in England. We measured effectiveness by the number of referrals resulting in programme attendance. We surveyed local commissioners about their use of financial incentives and linked this information to numbers of programme referrals and attendances from 5170 general practices between April 2016 and March 2018. We used multivariate probit regressions to identify commissioner characteristics associated with the use of different incentive types and negative binomial regressions to estimate their effect on practice rates of referral and attendance. Financial incentives were offered by commissioners in the majority of areas (89%), with 38% using structure incentives, 69% using process incentives and 22% using outcome incentives. Compared to practices without financial incentives, neither structure nor process incentives were associated with statistically significant increases in referrals or attendances, but outcome incentives were associated with 84% more referrals and 93% more attendances. Outcome incentives were the only form of pay-for-performance to stimulate more participation in this national disease prevention programme.

The effect of commissioning on Portuguese Primary Health Care units' performance: A four-year national analysis

BACKGROUND

Portugal underwent a paradigmatic Primary Health Care (PHC) reform in 2005. The reform implemented better health information systems, goal-oriented management, pay-for-performance schemes, functional autonomy for the front-line units, and the general adoption of commissioning processes. Since the implementation of the reform, the same set of indicators have been monitored nationally every year. However, from 2014-2016, the five Regional Health Administrations could individually select part of set of indicators to be commissioned. As the same some indicators were used commissioned in some regions, but not in others, a natural experimental setting to observe the impact of commissioning on the results by comparing the performance of commissioned versus non-commissioned indicators emerged and the effects of commissioning on PHC performance could be evaluated.

AIM

Our article aims to clarify the effect of commissioning on the results achieved by PHC units in Portugal following the implementation of the reform.

RESULTS

In general, the indicator values improved with time in the three types of units that existed after the reform. However, Model B Family Health Units ('Unidades de Saúde Familiar' or USFs that use pay-for-performance and are more mature) obtained the highest absolute indicator values, followed by Model A USFs (newer units with a fixed salary) and Personalised Health Care Units ('Unidades de Cuidados de Saúde Personalizados' that were created under the model before the reform and offer a fixed salary), respectively.

CONCLUSION

The results show a general increase in indicators in all PHC units. However, the indicators used in the commissioning processes exhibited a greater increase. There was no evidence that the better results exhibited by the commissioned indicators were achieved at the expense of a detrimental effect on non-commissioned indicators.

Effects of pay-for-performance for primary care physicians on diabetes outcomes in single-payer health systems: a systematic review

BACKGROUND

Although pay-for-performance (P4P) for diabetes care is increasingly common, evidence of its effectiveness in improving population health and health system sustainability is deficient. This information gap is attributable in part to the heterogeneity of healthcare financing, covered medical conditions, care settings, and provider remuneration arrangements within and across countries. We systematically reviewed the literature concentrating on whether P4P for physicians in primary and community care leads to better diabetes outcomes in single-payer national health insurance systems.

METHODS

Studies were identified by searching ten databases (01/2000-04/2018) and scanning the reference lists of review articles and other global health literature. We included primary studies evaluating the effects of introducing P4P for diabetes care among primary care physicians in countries of universal health coverage. Outcomes of interest included patient morbidity, avoidable hospitalization, premature death, and healthcare costs.

RESULTS

We identified 2218 reports; after exclusions, 10 articles covering 8 P4P interventions in 7 countries were eligible for analysis. Five studies, capturing records from 717,166 patients with diabetes, were graded as high-quality evaluations of P4P on health outcomes. Based on three quality studies, P4P can result in reduced risk of mortality over the longer term-when linked to performance metrics. However, studies from other jurisdictions, where P4P was not linked to specific patient-oriented objectives, yielded little or mixed evidence of positive health impacts.

CONCLUSION

Evidence of the effectiveness of P4P depends on whether physicians' incentive payments are explicitly tied to performance metrics. However, the most appropriate indicators for performance monitoring remain in question. More research with rigorous evaluation in different settings is needed.

Factors Associated with Practice-Level Performance Indicators in Primary Health Care in Hungary: A Nationwide Cross-Sectional Study

The performance of general practitioners (GPs) is frequently assessed without considering the factors causing variability among general medical practices (GMPs). Our cross-sectional national-based study was performed in Hungary to evaluate the influence of GMP characteristics on performance indicators. The relationship between patient’s characteristics (age, gender, education) and GMP-specific parameters (practice size, vacancy of GP’s position, settlement type, and county of GMP) and the quality of care was assessed by multilevel logistic regression models. The variations attributable to physicians were small (from 0.77% to 17.95%). The education of patients was associated with 10 performance indicators. Practicing in an urban settlement mostly increased the quality of care for hypertension and diabetes care related performance indicators, while the county was identified as one of the major determinants of variability among GPs’ performance. Only a few indicators were affected by the vacancy and practice size. Thus, the observed variability in performance between GPs partially arose from demographic characteristics and education of patients, settlement type, and regional location of GMPs. Considering the real effect of these factors in evaluation would reflect better the personal performance of GPs.

Primary health care quality indicators: An umbrella review

Nowadays, evaluating the quality of health services, especially in primary health care (PHC), is increasingly important. In a historical perspective, the Department of Health (United Kingdom) developed and proposed a range of indicators in 1998, and lately several health, social and political organizations have defined and implemented different sets of PHC quality indicators. Some systematic reviews in PHC quality indicators are reported but only in specific contexts and conditions. The aim of this study is to characterize and provide a list of indicators discussed in the literature to support managers and clinicians in decision-making processes, through an umbrella review on PHC quality indicators. The methodology was performed according to PRISMA Statement. Indicators from 33 eligible systematic reviews were categorized according to the dimensions of care, function, type of care, domains and condition contexts. Of a total of 727 indicators or groups of indicators, 74.5% (n = 542) were classified in process category and 89.5% (n = 537) with chronic type of care (n = 428; 58.8%) and effective domain (n = 423; 58.1%) with the most frequent values in categorizations by dimensions. The results of this overview of reviews are valuable and imply the need for future research and practice regarding primary health care quality indicators in the most varied conditions and contexts to generate new discussions about their use, comparison and implementation.

Uncertainty about the effort-performance relationship in threshold-based payment schemes

Incentive schemes often feature a threshold beyond which providers receive no additional payment for performance. We investigate whether providers' uncertainty about the relationship between effort and measured performance leads to financially unrewarded performance in such schemes. Using data from the British Quality and Outcomes Framework, we proxy general practitioners' uncertainty about the effort-performance relationship by their experience with the scheme and their span of control. We find evidence that providers respond to uncertainty by exerting financially unrewarded performance, suggesting that uncertainty may be a mechanism by which payers can extract unrewarded performance.

Funding models and medical dominance in interdisciplinary primary care teams: qualitative evidence from three Canadian provinces

BACKGROUND

Primary care in Canada is the first point of entry for patients needing specialized services, the fundamental source of care for those living with chronic illness, and the main supplier of preventive services. Increased pressures on the system lead to changes such as an increased reliance on interdisciplinary teams, which are advocated to have numerous advantages. The functioning of teams largely depends on inter-professional relationships that can be supported or strained by the financial arrangements within teams. We assess which types of financial environments perpetuate and which reduce the challenge of medical dominance.

METHODS

Using qualitative interview data from 19 interdisciplinary teams/networks in three Canadian provinces, as well as related policy documents, we develop a typology of financial environments along two dimensions, financial hierarchy and multiplicity of funding sources. A financial hierarchy is created when the incomes of some providers are a function of the incomes of other providers. A multiplicity of funding sources is created when team funding is provided by several funders and a team faces multiple lines of accountability.

RESULTS

We argue that medical dominance is perpetuated with higher degrees of financial hierarchy and higher degrees of multiplicity. We show that the financial environments created in the three provinces have not supported a reduction in medical dominance. The longstanding Community Health Centre model, however, displays the least financial hierarchy and the least multiplicity-an environment least fertile for medical dominance.

CONCLUSIONS

The functioning of interdisciplinary primary care teams can be negatively affected by the unique positioning of the medical profession. The financial environment created for teams is an important consideration in policy development, as it plays an important role in establishing inter-professional relationships. Policies that reduce financial hierarchies and funding multiplicities are optimal in this regard.

Funding and remuneration of interdisciplinary primary care teams in Canada: a conceptual framework and application

Background

Reliance on interdisciplinary teams in the delivery of primary care is on the rise. Funding bodies strive to design financial environments that support collaboration between providers. At present, the design of financial arrangements has been fragmented and not based on evidence. The root of the problem is a lack of systematic evidence demonstrating the superiority of any particular financial arrangement, or a solid understanding of options. In this study we develop a framework for the conceptualization and analysis of financial arrangements in interdisciplinary primary care teams.

Methods

We use qualitative data from three sources: (i) interviews with 19 primary care decision makers representing 215 clinics in three Canadian provinces, (ii) a research roundtable with 14 primary care decision makers and/or researchers, and (iii) policy documents. Transcripts from interviews and the roundtable were coded thematically and a framework synthesis approach was applied.

Results

Our conceptual framework differentiates between team level funding and provider level remuneration, and characterizes the interplay and consonance between them. Particularly the notions of hierarchy, segregation, and dependence of provider incomes, and the link between funding and team activities are introduced as new clarifying concepts, and their implications explored. The framework is applied to the analysis of collaboration incentives, which appear strongest when provider incomes are interdependent, funding is linked to the team as a whole, and accountability does not have multiple lines. Emergent implementation issues discussed by respondents include: (i) centrality of budget negotiations; (ii) approaches to patient rostering; (iii) unclear funding sources for space and equipment; and (iv) challenges with community engagement. The creation of patient rosters is perceived as a surprisingly contentious issue, and the challenges of funding for space and equipment remain unresolved.

Conclusions

The development and application of a conceptual framework is an important step to the systematic study of the best performing financial models in the context of interdisciplinary primary care. The identification of optimal financial arrangements must be contextualized in terms of feasibility and the implementation environment. In general, financial hierarchy, both overt and covert, is considered a barrier to collaboration.

Electronic supplementary material

The online version of this article (doi:10.1186/s12913-017-2290-4) contains supplementary material, which is available to authorized users.

Does enrollment in multidisciplinary team-based primary care practice improve adherence to guideline-recommended processes of care? Quebec's Family Medicine Groups, 2002-2010

BACKGROUND

We investigated whether multidisciplinary team-based primary care practice improves adherence to process of care guidelines, in the absence of financial incentives related to pay-for-performance.

METHODS

We conducted a natural experiment including 135,119 patients, enrolled with a general practitioner (GP) in a multidisciplinary team Family Medicine Group (FMG) or non-FMG practice, using longitudinal data from Quebec's universal insurer over the relevant time period (2000-2010). All study subjects had diabetes, chronic obstructive pulmonary disease, or heart failure and were followed over a 7-year period, 2 years prior to enrollment and 5 years after. We constructed indicators on adherence to disease-specific guidelines and composite indicators across conditions. We evaluated the effect of FMGs using propensity score methods and Difference-in-Differences (DD) models.

RESULTS

Rates of adherence to chronic disease guidelines increased for both FMG and non-FMG patients after enrollment, but not differentially so. Adherence to prescription-related guidelines improved less for FMG patients (DD [95% CI]=-2.83% [-4.08%, -1.58%]). We found no evidence of an FMG effect on adherence to consultation-related guidelines, (DD [95% CI]=-0.24% [-2.24%; 1.75%]).

CONCLUSIONS

We found no evidence that FMGs increased adherence to the guidelines we evaluated. Future research is needed to assess why this reform did not improve performance on these quality-of-care indicators.

Primary Care Doctors' Assessment of and Preferences on Their Remuneration

Despite numerous studies on primary care doctors' remuneration and their job satisfaction, few of them have quantified their views and preferences on certain types of remuneration. This study aimed at reporting these views and preferences on behalf of Greek doctors employed at public primary care. We applied a 13-item questionnaire to a random sample of 212 doctors at National Health Service health centers and their satellite clinics. The results showed that most doctors deem their salary lower than work produced and lower than that of private sector colleagues. Younger respondents highlighted that salary favors dual employment and claim of informal fees from patients. Older respondents underlined the negative impact of salary on productivity and quality of services. Both incentives to work at border areas and choose general practice were deemed unsatisfactory by the vast majority of doctors. Most participants desire a combination of per capita fee with fee-for-service; however, 3 clusters with distinct preferences were formed: general practitioners (GPs) of higher medical grades, GPs of the lowest medical grade, residents and rural doctors. Across them, a descending tolerance to salary-free schemes was observed. Greek primary care doctors are dissatisfied with the current remuneration scheme, maybe more than in the past, but notably the younger doctors are not intended to leave it. However, Greek policy makers should experiment in capitation for more tolerable to risk GPs and introduce pay-for-performance to achieve enhanced access and quality. These interventions should be combined with others in primary care's new structure in an effort to converge with international standards.

The impact of Value Incentive Program (VIP) on the quality of hospital care for acute stroke in Korea

OBJECTIVES

This study aims to analyze the impact of Value Incentive Program (VIP) on the quality improvement of acute stroke care, and to determine the difference of effect by the size of hospitals.

INTERVENTIONS

Adopting the VIP on the fifth acute stroke quality assessment.

DESIGN/SETTING/PARTICIPANTS

Using paired t-test and student t-test, we compared the quality assessment results of the third assessment, which was publicly reported without the VIP implementation and the fifth assessment, on which the VIP was applied. The subjects of the third assessment were acute stroke admissions in 201 hospitals (44 tertiary and 157 general hospitals) from January to March 2010. The fifth assessment included 201 hospitals (42 tertiary and 159 general hospitals) from March to May 2013.

MAIN OUTCOME MEASURES

Seven process indicators of acute stroke quality assessment and in-hospital mortality rate.

RESULT

In comparison to the third assessment, five of the seven process indicators showed statistically significant improvement in the fifth assessment. Also, there were significant decreases in the interquartile ranges of five process indicators. This phenomenon was more notable in general hospitals. The in-hospital mortality rate of hemorrhagic stroke in general hospitals showed a statistically significant decrease from 20.8% in the third assessment to 11.6% (P < 0.05) in the fifth assessment.

CONCLUSION

This study demonstrated that the VIP was effective in improving quality of acute stroke care. The improvement was more prominent in general hospitals, and led to reduced quality gaps among hospitals.

The effectiveness of payment for performance in health care: A meta-analysis and exploration of variation in outcomes

BACKGROUND

Pay for performance (P4P) incentive schemes are increasingly used world-wide to improve health system performance but results of evaluations vary considerably. A systematic analysis of this variation in the effects of P4P schemes is needed.

METHODS

Evaluations of P4P schemes from any country were identified by searching for and updating systematic reviews of P4P schemes in health care in four bibliographic databases. Outcomes using different measures of effect were converted into standardized effect sizes (standardized mean difference, SMD) and each study was categorized as to whether or not it found a positive effect. Subgroup analysis, meta-regression and multilevel logistic regression were used to investigate factors explaining heterogeneity. Random-effects models were used because they take into account heterogeneity likely to be due to differences between studies rather than just chance. Sensitivity analysis was used to test the effect of different assumptions.

FINDINGS

96 primary studies were identified; 37 were included in the meta-analysis and meta-regression and all 96 in the logistic regression. The proportion of observed variation in study results that can be explained by true heterogeneity (I²) was 99.9%. Estimates of effect of P4P schemes were lower in evaluations using randomized controlled trials (SMD=0.08; 95% CI: 0.01-0.15) compared to no controls (0.15; 95% CI: 0.09-0.21), and lower for those measuring outcomes (e.g., smoking cessation) (SMD=0.0; 95% CI: -0.01 to 0.01) compared to process measures (e.g., giving cessation advice) (0.18; 95% CI: 0.06-0.31). Adjusting for other design features and the evaluation method, the odds of showing a positive effect was three times higher for schemes with larger incentives (>5% of salary/usual budget) (OR=3.38; 95% CI: 1.07-10.64). There were non-statistically significant increases in the odds of success if the incentive is paid to individuals (as opposed to groups) (OR=2.0; 95% CI: 0.62-6.56) and if there is a lower perceived risk of not earning the incentive (OR=2.9; 95% CI: 0.78-10.83). Schemes evaluated using less rigorous designs were 24 times more likely to have positive estimates of effect than those using randomized controlled trials (OR=24; 95% CI: 6.3-92.8).

INTERPRETATION

Estimates of the effectiveness of incentive schemes on health outcomes are probably inflated due to poorly designed evaluations and a focus on process measures rather than health outcomes. Larger incentives and reducing the perceived risk of non-payment may increase the effect of these schemes on provider behavior.

Risk Adjustment for Lumbar Dysfunction: Comparison of Linear Mixed Models With and Without Inclusion of Between-Clinic Variation as a Random Effect

BACKGROUND

Valid comparison of patient outcomes of physical therapy care requires risk adjustment for patient characteristics using statistical models. Because patients are clustered within clinics, results of risk adjustment models are likely to be biased by random, unobserved between-clinic differences. Such bias could lead to inaccurate prediction and interpretation of outcomes.

PURPOSE

The purpose of this study was to determine if including between-clinic variation as a random effect would improve the performance of a risk adjustment model for patient outcomes following physical therapy for low back dysfunction.

DESIGN

This was a secondary analysis of data from a longitudinal cohort of 147,623 patients with lumbar dysfunction receiving physical therapy in 1,470 clinics in 48 states of the United States.

METHODS

Three linear mixed models predicting patients' functional status (FS) at discharge, controlling for FS at intake, age, sex, number of comorbidities, surgical history, and health care payer, were developed. Models were: (1) a fixed-effect model, (2) a random-intercept model that allowed clinics to have different intercepts, and (3) a random-slope model that allowed different intercepts and slopes for each clinic. Goodness of fit, residual error, and coefficient estimates were compared across the models.

RESULTS

The random-effect model fit the data better and explained an additional 11% to 12% of the between-patient differences compared with the fixed-effect model. Effects of payer, acuity, and number of comorbidities were confounded by random clinic effects.

LIMITATIONS

Models may not have included some variables associated with FS at discharge. The clinics studied may not be representative of all US physical therapy clinics.

CONCLUSIONS

Risk adjustment models for functional outcome of patients with lumbar dysfunction that control for between-clinic variation performed better than a model that does not.