Understanding adherence to therapeutic guidelines: a multilevel analysis of statin prescription in the Skaraborg Primary Care Database

Abstract

In Skaraborg, Sweden, the economic responsibility for tax-financed prescription drug costs was transferred from the regional administrative level to the local level (health care centre; HCC) in 2003. The aim of this study was to investigate the impact of this decentralization of economic responsibility on adherence to guidelines for prescribing lipid-lowering drugs. Data from all 24 public HCCs in Skaraborg on prescriptions for lipid-lowering drugs during 2003 and 2005 were extracted from the Skaraborg Primary Care Database (SPCD). Multilevel regression analysis (MLRA) was used to disentangle the variances at different levels of data (patient, physician, HCC). The outcome variable on the patient level was the prescription of the recommended statin (yes/no). Sex and age of the patients and sex, age and occupational status of the physician were included as fixed effects. The variance was expressed as the median odds ratio (MOR). The prevalence of adherence to guidelines for the prescription of statins increased from 77% in 2003 to 84% in 2005. The MLRA showed that in 2003 the variance was equally distributed between the HCC and physician levels (MOR(HCC2003)=1.89 vs. MOR(PHYSICIAN2003)=1.88). The variance between physicians and between HCCs decreased considerably between 2003 and 2005. The inclusion of individual and physician characteristics did not explain any of the remaining variance. The decentralized budget appears to have increased adherence to guidelines and reduced inefficient variation in prescribing.