[Evaluation of family doctor centred medical care based on AOK routine data in Baden-Württemberg].
The agreement on family-doctor centred care (Hausarztzentrierte Versorgung, "HzV") pursuant to Sect. 73b, Volume V of the German Social Security Code became effective in Baden-Wuerttemberg, Germany, on July 1(st), 2008. This complex intervention, which is voluntary for both family doctors and patients, aims to strengthen the coordinative function of family practices. As a result, this intervention is believed to increase the quality of medical health care for persons insured - in the medium to long-term - and thereby, ideally, to additionally save expenses. Working package 1 was one out of a total of four working packages and focused on the evaluation of potential intervention effects of the HzV intervention based on the analyses of AOK routine data in Baden-Wuerttemberg. A total of 1.44 million insured persons were eligible for the present analyses. Insured adults voluntarily participating in the family doctor-centred health care intervention (HzV insured persons: n=580,924 in the intervention group) of the AOK were compared to those not participating in this intervention (non-HzV insured persons: n=862,237 in the control group). For both HzV and non-HzV insured persons, a comparison of each outcome of interest (encounters with family doctors, encounters with specialists, rate of hospitalisations, duration of hospitalisations, rate of re-hospitalisations, costs of pharmacotherapy, rate of polypharmacy, rate of Me-Too pharmaceuticals) was conducted for quarters 3 and 4 of 2008 as well as for quarters 3 and 4 in 2010. Both groups of insured persons differed in that they either participated in the HzV intervention between January 1, 2009 and June 30, 2011 or not. Before January 1, 2009 individuals in both groups did not participate in the HzV intervention. This design allowed for both longitudinal and cross-sectional comparisons. Moreover, the design implicitly controlled for potential seasonal bias. In order to adjust for relevant covariates (insured persons age, gender, nationality, insurance state, morbidity), multivariate multilevel regression models were developed and applied. On average, HzV insured persons were about 3 years older (56.2 ± 27.3 vs. 53.1 ± 18.4 years) and had higher levels of comorbidity (Charlson Comorbidity Index: 1.45 ± 1.86 vs. 1.19 ± 1.71). No significant differences in terms of rate and duration of hospitalisations were observed. The same applied to the number of rehospitalisations within 30 days. After adjustment for covariates, however, an increase in visits to the respective family doctor of 38% was found in the intervention group. Moreover, a decrease of encounters to specialists with and without referrals from family doctors could be observed (-29.8 % and -12.5%, respectively). Interestingly, even costs of pharmacotherapy, polypharmacy and prescriptions of Me-Too drugs were statistically significantly lower or less frequent, respectively, in the group of HzV insured persons. In conclusion, besides the observed associations in terms of pharmacotherapy, the HzV intervention appears to have advantageous effects in terms of family doctor centred health care.