Characteristics of primary care physicians and their practices associated with mammography rates for older women.

BACKGROUND

Mammography screening rates are below national recommendations for older women. Understanding the relation between the characteristics of primary care physicians (PCPs) and mammography rates for older women can help to target screening improvement efforts.

METHODS

Subjects were 2527 PCPs practicing in Michigan between 1997 and 1998. A cross-sectional design used Medicare data to identify women age 68 years or older in 1998 whom PCPs treated in 1997-1998 and to determine whether these women had a mammogram between 1996 and 1998. Eligible women were Medicare beneficiaries age 65 years or older by 1996, residing in Michigan from 1996 to 1998, without specified comorbidities likely to affect decisions regarding mammography. Correlations and multiple regressions examined the relation between this score and characteristics of both PCPs and their practice populations of older women.

RESULTS

Mammography rates across physicians' practices ranged from 3-100% (mean = 59%, standard deviation = 17%). Five predictors accounted for 55% of the variance in mammography rates across practices. Higher mammography rates were found to be independently related to physicians who have: a lower mean age for female Medicare patients, a higher mean number of physicians billing for patients' care, a lower mean number of inpatient admissions, obstetrics/gynecology practices, and a higher mean education level in patient's zip code (beta weights >/= 0.25, P < 0.0001).

CONCLUSIONS

PCPs vary substantially with regard to mammography rates for older women. Mammography rates vary more with the population of patients in physicians' practices than with commonly measured personal characteristics of physicians. Mammography rates should be adjusted for patient population to target individual PCPs with low mammography rates for interventions.