Mammography use by elderly women: a methodological comparison of two national data sources.

PURPOSE: Estimates of mammography utilization vary considerably, depending on the data source. Among women aged 65 years and older, recent estimates of annual mammography derived from the 1992 National Health Interview Survey (NHIS) were 50% higher than estimates from Medicare claims. We investigated possible reasons for the different estimates. METHODS: We identified differences in the populations covered by the two data sources and made appropriate adjustments. Differences due to age were addressed by age restriction and age adjustment. Women in health maintenance organizations were eliminated from the NHIS sample so it more closely resembled the Medicare database, and estimates of mammography utilization by noninstitutionalized women were derived for Medicare to increase comparability with NHIS. By using the Medicare Current Beneficiary Survey to obtain individual-level comparisons between self-report and claims, we explored potential biases in self-reported data and missing claims. RESULTS: Differences between the sample populations accounted for more than one-fourth of the rate difference. About half of the difference could be attributed to erroneous self-reports, biases in self-reported dates (forward and reverse telescoping) and missing Medicare claims. CONCLUSIONS: Most of the discrepancy between the two data sources can be plausibly explained. However, caution must be used in using either data source alone, or both together, to represent the "true" mammography rate.

Evaluation of the 1990 Centers for Disease Control and Prevention smoke-free policy.

PURPOSE: To determine the prevalence of tobacco use among Centers for Disease Control and Prevention (CDC)/Agency for Toxic Substances and Disease Registry (ATSDR) employees and the effect of the smoke-free policy on smoking behavior and air quality at work. DESIGN: A stratified telephone survey of 1181 CDC/ATSDR employees randomly selected from employee rosters. SETTING: CDC/ATSDR work sites in Atlanta, Georgia, and other major CDC locations throughout the United States and Puerto Rico. SUBJECTS: Randomly selected employees of CDC/ATSDR1, or about 22% of the total CDC/ATSDR population; 98% of eligible persons selected agreed to participate. MEASURES: Demographic and smoking history variables, attitudes toward and impact of the smoke-free policy on smoking behavior, and self-report changes in air quality were the measures used. RESULTS: Overall cigarette smoking prevalence was only 11.1%. One percent reported using chewing tobacco, 1.1% reported smoking a pipe, and 1.4% reported smoking cigars. Average self-reported, daily cigarette consumption significantly decreased after the smoking ban took effect. Overall, 90% of the employees supported the smoke-free policy, and 80% of the employees believed that smokers were complying with the smoke-free policy. Most employees believed that the air quality of work areas and nonwork areas (65% and 69%, respectively) had improved since the smoke-free policy was implemented. CONCLUSIONS: These findings are consistent with previous evaluations of smoke-free policies and suggest that most employees are generally supportive of workplace smoking restrictions. Such policies can also have a positive impact on smoking behavior and perceived air quality.