Practice variation in surgical procedures and IUD-insertions among general practitioners in Norway - a longitudinal study.

Background: Studies of Primary Health Care (PHC) reveal considerable practice variations in terms of the range of services provided. In Norway, general practitioners (GPs) are traditionally expected to perform IUD-insertions and several surgical procedures as a part of comprehensive PHC. We aimed to investigate variation in the provision of surgical procedures and IUD-insertions across GPs and over time and explore determinants of such variation.
Methods: Retrospective registry study of Norwegian GPs. From a comprehensive database of GPs' reimbursement claims, we obtained procedure codes and GP characteristics such as age, gender, list size and municipality characteristics from 2006 through 2013. Multivariable logistic regression models were fitted to explore determinants of practice variation.
Results: We extracted data from 4,828 GPs. In 2013, 91.0, 76.1 and 74.8% were reimbursed at least once for minor and major surgical procedures and IUD-insertion, respectively. Female GPs had lower odds for performing major surgical procedures (OR 0.38, 95% CI 0.32-0.45) and higher odds for performing IUD-insertions (OR 6.28, 95% CI 4.47-8.82) than male GPs. Older GPs and GPs with shorter patient lists were less likely to perform surgical procedures. GPs with longer patient lists had higher odds for performing IUD-insertions. The proportion of GPs performing surgical procedures increased over time, while the proportion decreased for IUD-insertions. The number of IUD-insertions in specialist care increased from 12,575 in 2011 to 15 216 (+21.0%) in 2014.
Conclusion: We observed a large variation in the provision of surgical procedures and IUD-insertions amongst GPs in Norway. The GPs' age, gender, list size and size of municipality were associated with performing the procedures. Our findings suggest a shift of IUD-insertions from primary to specialist care.