Comparing potentially avoidable hospitalization rates related to ambulatory care sensitive conditions in Switzerland: the need to refine the definition of health conditions and to adjust for population health status

Abstract

BackgroundRegional rates of hospitalization for ambulatory care sensitive conditions (ACSC) are used to compare the availability and quality of ambulatory care but the risk adjustment for population health status is often minimal. The objectives of the study was to examine the impact of more extensive risk adjustment on regional comparisons and to investigate the relationship between various area-level factors and the properly adjusted rates.MethodsOur study is an observational study based on routine data of 2 million anonymous insured in 26 Swiss cantons followed over one or two years. A binomial negative regression was modeled with increasingly detailed information on health status (age and gender only, inpatient diagnoses, outpatient conditions inferred from dispensed drugs and frequency of physician visits). Hospitalizations for ACSC were identified from principal diagnoses detecting 19 conditions, with an updated list of ICD-10 diagnostic codes. Co-morbidities and surgical procedures were used as exclusion criteria to improve the specificity of the detection of potentially avoidable hospitalizations. The impact of the adjustment approaches was measured by changes in the standardized ratios calculated with and without other data besides age and gender.Results25% of cases identified by inpatient main diagnoses were removed by applying exclusion criteria. Cantonal ACSC hospitalizations rates varied from to 1.4 to 8.9 per 1,000 insured, per year. Morbidity inferred from diagnoses and drugs dramatically increased the predictive performance, the greatest effect found for conditions linked to an ACSC. More visits were associated with fewer PAH although very high users were at greater risk and subjects who had not consulted at negligible risk. By maximizing health status adjustment, two thirds of the cantons changed their adjusted ratio by more than 10 percent. Cantonal variations remained substantial but unexplained by supply or demand.ConclusionAdditional adjustment for health status is required when using ACSC to monitor ambulatory care. Drug-inferred morbidities are a promising approach.

Rates of admission for ambulatory care sensitive conditions in France in 2009–2010: trends, geographic variation, costs, and an international comparison

“…Further, the study of ACSC in three metropolitan areas in France [25] found a different relationship between primary care physician and ACSC rates than we found; this might be due, in part, to the different level of geographic analysis in the two studies. Finally, we were not able to correct for health status, or to use additional sources of data (like medication utilization) to identify other comorbid conditions: factors that might have explained the admission rates that we found [23].…”

“…Expansion of primary care access in Brazil reduced hospitalizations for ACSCs between 1999 and 2007 [21,22]. When compared to unadjusted measures of rates of ACSCs in 26 cantons in Switzerland, researchers found that when they applied exclusion criteria or included information on comorbidities and health status, adjusted rates of ACSCs declined; however, they found no relationship between access to primary care physicians and rates of ACSCs [23]. Higher densities of specialists and generalists in Germany were associated with lower rates of hospitalization for a limited number of ACSCs, while unemployment, living in a rural setting, and the number of hospital beds per capita were associated with higher rates [24].…”

GP supply, deprivation and emergency admission to hospital for COPD and diabetes complications in counties across Ireland: an exploratory analysis

“…The only aspect of population health need that was examined was deprivation. Previous research has highlighted the role that overall health status and comorbidity can play in driving rates of admission for ambulatory-care sensitive conditions [13]. The analysis would be strengthened by more variables reflecting health need at the county level, such as prevalence of chronic disease, or risk factors such as smoking or obesity.…”

Desigualdades intraurbanas de taxas de internações por condições sensíveis à atenção primária na região central do Brasil

“…Studies have reported varying rates of admissions for ACSCs across different countries. In Italy, Agabiti et al 7 observed rates of 26.1 per 10,000 population, while in Switzerland, Eggli et al 8 found rates of 10 per 1,000 population among patients with private health insurance. The most common causes of ACSC admissions described in the national and international literature are gastroenteritis, kidney and urinary tract infections, heart failure, angina, asthma, and diabetes mellitus [9][10][11][12][13][14][15] .…”