Improving follow-up after an abnormal pap smear: results from a quasi-experimental intervention study

The success of cervical cancer control programs depends on regular screening with the Pap smear test and prompt and appropriate treatment of early neoplastic lesions. Recognizing the potentially grave consequences of lack of follow-up for abnormal Pap smears, numerous intervention studies have tested the impact of a variety of strategies to increase return for follow-up. The majority of these studies were evaluated under controlled experimental conditions. Despite the encouraging findings of these trials, the next step in the research continuum requires that the effectiveness of these interventions be demonstrated in real world settings before full implementation is initiated. We report the results of an evaluation study assessing the combined effectiveness of three intervention modalities found effective in prior randomized studies: a tracking follow-up protocol, transportation incentives, and financial incentives. This study used a before-after, nonequivalent control group design to assess the impact of a multifaceted intervention that included a computerized tracking protocol with transportation and financial incentives. The study was implemented at two major hospitals, two comprehensive health centers (CHC), and nine public health centers (PHC) under the jurisdiction of the Los Angeles County Department of Health Services. One hospital, one CHC, and the four PHC located in the catchment area of the CHC were selected as experimental sites. The control sites - one hospital, one CHC, and five PHC - provided usual care. All women with an abnormal Pap smear at the intervention and control sites were included in the study. The study consisted of a 1-year period of baseline data collection (September 1989-August 1990), followed by a 2(1/2)-year intervention period (September 1990-February 1993). During the intervention period, the intervention protocol was implemented at the experimental sites, and the control sites provided usual care. Overall, we found that the rates of receipt of follow-up care were consistent with those found in similar studies. In contrast to results obtained in these prior randomized trials, we did not find strong and consistent evidence for intervention effects. Significant findings emerged only at the CHC and hospital levels and only for selected years. Results underscore the importance of testing interventions in real world conditions before large-scale implementation is initiated. In addition, this study highlights the challenge of detecting intervention effects in large-scale studies because of the greater measurement difficulties in field studies as compared with controlled experiments.