Impact of Disease Prevalence Adjustment on Hospitalization Rates for Chronic Ambulatory Care-Sensitive Conditions in Germany.
To explore effects of disease prevalence adjustment on ambulatory care-sensitive hospitalization (ACSH) rates used for quality comparisons.



County-level hospital administrative data on adults discharged from German hospitals in 2011 and prevalence estimates based on administrative ambulatory diagnosis data were used.



A retrospective cross-sectional study using in- and outpatient secondary data was performed.



Hospitalization data for hypertension, diabetes, heart failure, chronic obstructive pulmonary disease, and asthma were obtained from the German Diagnosis Related Groups (DRG) database. Prevalence estimates were obtained from the German Central Research Institute of Ambulatory Health Care.



Crude hospitalization rates varied substantially across counties (coefficients of variation [CV] 28-37 percent across conditions); this variation was reduced by prevalence adjustment (CV 21-28 percent). Prevalence explained 40-50 percent of the observed variation (r = 0.65-0.70) in ACSH rates for all conditions except asthma (r = 0.07). Between 30 percent and 38 percent of areas moved into or outside condition-specific control limits with prevalence adjustment.



Unadjusted ACSH rates should be used with caution for high-stakes public reporting as differences in prevalence may have a marked impact. Prevalence adjustment should be considered in models analyzing ACSH.
Niederrhein University of Applied Sciences, Krefeld, Germany.
Johannes
J
Pollmanns
UC Davis Division of General Medicine, Sacramento, CA.
Patrick S
PS
Romano
Niederrhein University of Applied Sciences, Krefeld, Germany.
Maria
M
Weyermann
Philipps-Universität Marburg, Marburg, Germany.
Max
M
Geraedts
Niederrhein University of Applied Sciences, Krefeld, Germany.
Saskia E
SE
Drösler
D019985:Benchmarking; D002908:Chronic Disease / Q000453:epidemiology*; D003430:Cross-Sectional Studies; D005260:Female; D005858:Germany; D006760:Hospitalization / Q000706:statistics & numerical data*; D006801:Humans; D008297:Male; D015995:Prevalence; D019984:Quality Indicators, Health Care; D012189:Retrospective Studies; D020379:Risk Adjustment; D062206:Spatial Analysis
Ambulatory care-sensitive conditions; quality of care; small area analysis