Testing efficacy with detection controlled estimation: an application to telemedicine

Medical regulation and health outcomes: the effect of the physician examination requirement

This article investigates the effect on health outcomes of the regulation prohibiting physicians from prescribing drugs without a prior physical examination. This requirement could improve health by reducing illegal access to prescription drugs. However, it reduces access to health care by making it more difficult for patients and physicians to use many forms of telemedicine. Thus, this regulation generates a trade-off between access and safety. Using matching techniques, we find that the physician examination requirement leads to an increase of 1% in mortality rates from disease, the equivalent of 8.5 more deaths per 100,000 people, and a decrease of 6.7% in injury mortality, the equivalent of 2.5 deaths per 100,000 people. The magnitude of these effects is larger in rural areas and in areas with low physician density and is accompanied by an 18% increase in the number of days lost each month to illness.

Cost Analysis in Telemedicine: Empirical Evidence From Sites in Arizona

CONTEXT

Support of telemedicine for largely rural and ethnically diverse populations is premised on expectations that it increases opportunities for appropriate and timely medical services, and that it improves cost-effective service delivery.

PURPOSE

To understand the cost-effectiveness of telemedicine in 8 small and/or rural sites in Arizona.

METHODS

A cost analysis framework was used to measure the efficacy of telemedicine in the selected sites from May 1, 2000, to April 30, 2001.

FINDINGS

The costs for telemedicine services in half the study sites were more than the costs for conventional face-to-face diagnosis when the volume of telemedicine services used at a site was relatively low. This result persisted even when the opportunity cost for the patients in accessing more traditional types of care was included in the cost estimates.

CONCLUSIONS

These preliminary findings suggest that telemedicine in some instances may not be cost-effective for providing medical specialists for underserved communities, particularly if these networks are underutilized by the patient population. Further analyses are needed to assess factors influencing utilization patterns of telemedicine services by underserved and ethnic communities before implementing these programs at clinical sites.

False positive mammograms and detection controlled estimation

OBJECTIVE

To investigate the causes of false positive in mammograms.

DATA SOURCES

Secondary data collected from extracts from computerized medical records from 1999 from five thousand patients at a single hospital in a medium-sized Southern city.

STUDY DESIGN

Retrospective analysis of electronic medical data on screening and diagnostic mammograms. Detection-controlled estimation (DCE) was used to compare the efficacy of alternative readers of mammogram films. Analysis was also conducted on follow-up exams of women who tested positive in the first stage of investigation. Key variables included whether the patient had had a prior mammogram, age of the patient, and identifiers for the individual physicians.

DATA COLLECTION/EXTRACTION METHODS

Hospital maintains electronic medical records (EMR) on all patients. Extracts were performed on this EMR system under the guidance of clinical expertise. Data were collected for all women who had mammograms in 1999. Random samples were employed for screening mammograms, and all data was used for diagnostic mammograms.

PRINCIPAL FINDINGS

Study results imply that access to a previous mammogram greatly reduces the incidence of false positives readings. This has important consequences for benefit-cost, and cost-effectiveness analysis of mammography. Were previous mammograms always available, the results imply the number of false positives would decrease by at least half. The results here also indicate that there is no reason to believe this decrease in false positive would be accompanied by an increase in the number of false negatives. Other attributes also affected the number of false positives. Mondays and Wednesdays appear to be more prone to false positives than the other days in the week. There is also some disparity in false positive outcomes among the five physicians studied. With respect to detection-controlled estimation, the results are mixed. With follow-up data, the DCE estimator appears to generate reasonable, robust results. Without follow-up data, however, the DCE estimator is far less precise.

CONCLUSIONS

Study results imply that access to a previous mammogram reduces by at least half the incidence of false positives readings. This has important consequences for benefit-cost, and cost-effectiveness analysis of mammography.