Assessing the effect of a regional integrated care model over ten years using quality indicators based on claims data - the basic statistical methodology of the INTEGRAL project.

BACKGROUND: The regional integrated health care model "Healthy Kinzigtal" started in 2006 with the goal of optimizing health care and economic efficiency. The INTEGRAL project aimed at evaluating the effect of this model on the quality of care over the first 10 years. METHODS: This methodological protocol supplements the study protocol and the main publication of the project. Comparing quality indicators based on claims data between the intervention region and 13 structurally similar control regions constitutes the basic scientific approach. Methodological key issues in performing such a comparison are identified and solutions are presented. RESULTS: A key step in the analysis is the assessment of a potential trend in prevalence for a single quality indicator over time in the intervention region compared to the corresponding trends in the control regions. This step has to take into account that there may be a common - not necessarily linear - trend in the indicator over time and that trends can also appear by chance. Conceptual and statistical approaches were developed to handle this key step and to assess in addition the overall evidence for an intervention effect across all indicators. The methodology can be extended in several directions of interest. CONCLUSIONS: We believe that our approach can handle the major statistical challenges: population differences are addressed by standardization; we offer transparency with respect to the derivation of the key figures; global time trends and structural changes do not invalidate the analyses; the regional variation in time trends is taken into account. Overall, the project demanded substantial efforts to ensure adequateness, validity and transparency.

Ten-Year Evaluation of the Population-Based Integrated Health Care System "Gesundes Kinzigtal".

BACKGROUND: The population-based integrated health care system called "Gesundes Kinzigtal" (Integrierte Versorgung Gesundes Kinzigtal, IVGK) was initiated more than 10 years ago in the Kinzig River Valley region, which is located in the Black Forest in the German state of Baden-Württemberg. IVGK is intended to optimize health care while maximizing cost-effectiveness. It consists of programs for promoting health and for enabling cooperation among service providers, as well as of a shared-savings contract that has enabled resources to be saved every year. The goal of the present study was to investigate trends in the quality of care provided by IVGK over the past ten years in comparison to conventional care. METHODS: This is a non-randomized observational study with a control-group design (Kinzig River Valley versus 13 structurally comparable control regions), employing data collected by AOK, a large statutory health-insurance provider in Germany, over the period 2006-2015. Quality assessment was conducted with the aid of a set of indicators, developed by the authors, that was based exclusively on claims data. The statistical analysis of the trends in these indicators over time was conducted with preset criteria for the relevance of any observed changes, as well as preset mechanisms of controlling for confounding factors. RESULTS: For 88 of the 101 evaluable indicators, no relevant difference was seen between the trend over time in the region of the intervention and the average trend in the control regions. Relevant differences in favor of the IVGK were observed for six indicators, and negatively divergent trends compared to the controls were observed for seven indicators. In the main summarizing statistical analysis, no positive or negative difference was found between the Kinzig River Valley and the other regions with respect to trends in the health-care indicators over time. CONCLUSION: An evaluation based on 101 indicators derived from health-insurance data did not reveal any improvement of the quality of care by IVGK and the totality of the programs that were implemented under it. However, under the conditions of the shared-savings contract, no relevant diminution in the quality of care was observed over a period of 10 years either, compared with structurally similar control regions without an integrated care model.

Study protocol for a quasi-experimental claims-based study evaluating 10-year results of the population-based integrated healthcare model 'Gesundes Kinzigtal' (Healthy Kinzigtal): the INTEGRAL study.

INTRODUCTION: Patients often experience interface problems when treated by different specialists and in different healthcare sectors. Integrated care concepts aim to reduce these problems. While most integrated healthcare models focus on individual diseases, the integrated care model 'Gesundes Kinzigtal' applies a population-based approach and addresses the full spectrum of morbidities for a population defined by area of residence-the Kinzigtal. A special feature of the model is the joint savings contract between the regional management company and the statutory health insurers. The INTEGRAL study aims at assessing the effectiveness of 'Gesundes Kinzigtal' under routine conditions in comparison to conventional care over a period of 10 years in order to understand the benefits but also the potential for (unintended) harms. METHODS AND ANALYSIS: Database Claims data from statutory health insurance funds 2005-2015. The evaluation consists of a quasi-experimental study, with Kinzigtal as intervention region, at least 10 further regions with a similar population and healthcare infrastructure as primary controls and an additional random sample of insurees from the federal state of Baden-Württemberg as secondary controls. Model-specific and 'non-specific' indicators adopted from the literature and enriched by focus group interviews will be used to evaluate the model's effectiveness and potential unintended consequences by analysing healthcare utilisation in general. Temporal trends per indicator in the intervention region will be compared with those in each control region. The overall variation in trends for the indicators across all regions provides information about the potential to modify an indicator due to local differences in the healthcare system. ETHICS AND DISSEMINATION: Ethic Commission of the Faculty of Medicine, Philipps-University Marburg (ek_mr_geraedts_131117). Results will be discussed in workshops, submitted for publication in peer-review journals and presented at conferences. TRIAL REGISTRATION NUMBER: DRKS00012804.