[A systematic review on population-based indicators of the quality of care in formal and informal provider networks and their application in health economic evaluations].

BACKGROUND

Provider networks in healthcare can emerge as either formal or informal networks. For sector-encompassing population-based quality measurement in informal networks, which allows for conclusions about the cost-effectiveness of care for home-dwelling persons in need of care, a comprehensive review on suitable quality indicators that can be derived from German social health insurance claims data is still lacking.

OBJECTIVE

Primary review questions: Which population-based indicators of quality of care in formal and informal provider networks are described in the international literature? Which of these indicators are used as outcome parameters in health economic evaluations, and what are the methodological approaches in these evaluations? Rating approaches and methods for establishing thresholds as well as the validity and suitability of quality indicators to predict quality of care as well as the potential for the calculation of quality indicators based on German social health insurance claims data are included in the secondary review questions.

SEARCH METHODS

Databases searched in May 2017 and July 2018 included PubMed, The Cochrane Library und NHS EED, CINAHL, GeroLit and EconLit. In addition, we hand-searched references of the studies identified and screened the project database Health Services Research Germany.

SELECTION CRITERIA

Quantitative design, German or English language. Any kind of formal or informal network for which distinct members regarding single providers are named and population-based quality indicators for adults (18 years or older) are described.

DATA COLLECTION AND ANALYSIS

Two authors (Cohen's Kappa = 0.64) independently screened titles, abstracts and full texts. A third independent reviewer was consulted in cases of uncertainty regarding the inclusion of studies. Critical appraisal was conducted using AMSTAR, the Cochrane Risk-of-Bias Tool, the Newcastle-Ottawa Scale (NOS), the Appraisal Tool for Cross-Sectional Studies (AXIS) and the criteria of the Drummond Checklist.

MAIN RESULTS

137 studies were included, five of which evaluated informal provider networks and applied indicators for medical conditions such as diabetes mellitus or heart failure or events like ambulatory care-sensitive hospitalisations, which were also utilized for formal networks. Five out of 14 health economic evaluations also assessed associations between costs and quality of care. The majority of studies did not include evidence on rating approaches and/or thresholds. Even though the validity and reliability of the used data in single studies is frequently discussed, only one in four of the included studies undertook a discussion of the suitability of the applied indicators. 121 studies explored indicators that can, in whole or in part, potentially be calculated on the basis of German social health insurance claims data and that target medical conditions such as osteoarthritis, asthma, chronic pain, chronic obstructive pulmonary disease, cardiovascular disease, dementia, diabetes mellitus, osteoporosis or mental health disorders as well as ambulatory care-sensitive events, appropriate medication of the elderly and polypharmacy, preventive care and continuity of care.

AUTHORS' CONCLUSIONS: This systematic review identified quality indicators that were predominantly used in formal provider networks and, with sufficient testing and further development, include the possibility of being used for measuring the quality of care in informal networks. The need for further research on suitable approaches to measure the interactions of quality of care and costs and on the validity, reliability and predictive suitability of single indicators as well as the finding that quality indicators especially developed for the German ambulatory sector were rarely used in the included studies constitute promising starting points for both an intensified methodological debate and the critical discussion of issues concerning population-based, sector-encompassing measurement of quality of care in health services research.