PT - JOURNAL ARTICLE AU - Peter Franks AU - Colin Cameron AU - Klea D. Bertakis TI - On Being New to an Insurance Plan: Health Care Use Associated With the First Years in a Health Insurance Plan AID - 10.1370/afm.24 DP - 2003 Sep 01 TA - The Annals of Family Medicine PG - 156--161 VI - 1 IP - 3 4099 - http://www.annfammed.org/content/1/3/156.short 4100 - http://www.annfammed.org/content/1/3/156.full SO - Ann Fam Med2003 Sep 01; 1 AB - BACKGROUND We wanted to compare health care utilization and costs in the first year of being in a health insurance plan with those of subsequent years. METHODS We used claims data from an independent practitioner association (IPA)-style managed care organization in the Rochester, NY, metropolitan area from 1996 through 1999. Cross-sectional and panel analyses of up to 4 years of claims data were conducted, involving 335,547 adult patients assigned to the panels of 687 primary care physicians (internists and family physicians). Multivariate analyses, adjusting for age, sex, case mix, and socioeconomic status derived from ZIP codes, examined the relationship between the first year of health insurance and Papanicolaou tests, mammograms in women older than 40 years, physician use, avoidable hospitalization, and expenditures. RESULTS After multivariate adjustment, the first year of insurance was associated with a higher risk of not getting a mammogram, a higher risk of avoidable hospitalization, greater likelihood of visiting a physician, and higher expenditures, especially for testing. There was no relationship, however, between Papanicolaou test compliance and year of enrollment. CONCLUSIONS The findings suggest there might be adverse clinical and financial implications associated with changing insurance.