The assessment of health policy changes using the time-reversed crossover design.

AUTOR(ES)

Sollecito, W A

RESUMO

The time-reversed crossover design is a quasi-experimental design which can be applied to evaluate the impact of a change in health policy on a large population. This design makes use of separate sampling and analysis strategies to improve the validity of conclusions drawn from such an evaluation. The properties of the time-reversed crossover design are presented including the use of stratification on outcome in the sampling stage, which is intended to improve external validity. It is demonstrated that, although this feature of the design introduces internal validity threats due to regression toward the mean in extreme-outcome strata, these effects can be measured and eliminated from the test of significance of treatment effects. Methods for within- and across-stratum estimation and hypothesis-testing are presented which are similar to those which have been developed for the traditional two-period crossover design widely used in clinical trials. The procedures are illustrated using data derived from a study conducted by the United Mine Workers of America Health and Retirement Funds to measure the impact of cost-sharing on health care utilization among members of its health plan.

Documentos Relacionados

• Discrimination of Time-Reversed Harmonic Complexes by Normal-Hearing and Hearing-Impaired Listeners
• Patterns of outpatient mental health care over time: some implications for estimates of demand and for benefit design.
• Capturing and using clinical outcome data: implications for information systems design.
• A simple vacuum blotter design.
• Intelligent computational assistance for experiment design.