A claims data approach to defining an episode of care

Objective. To utilize health services research techniques in developing an episode of care using an administrative data set. This method is demonstrat ed for an episodic clinical condition, migraine. Data Sources. Medicaid administrative data set of 3,372 patients with a dia gnosis of migraine (ICD-9-CM 346.0, 346.1) in the state of Pennsylvania bet ween May 1990 and March 1992. Study Design. The duration of a migraine episode was measured by assessing the magnitude of resource utilization and the proportion of patients with c harges in the period after the index migraine as compared to the period bef ore the index migraine. A confidence interval (CI) was developed around eac h measure using bootstrap techniques. Data Collection Methods. All charge data were extracted daily for a 113-day observation period surrounding each index migraine in order to observe the duration of impact of a migraine diagnosis on resource utilization. Principal Findings. The lower limits of both the 95% and 99% CIs for the di fference in charges are greater than 0 for three weeks. The lower limits of both CIs for the difference in the proportion of patients with charges are above 0 for six weeks. Conclusions. Our analysis demonstrates that a health services research fram ework can be used to define an episode of care for a chronic disease catego ry such as migraine. This method can be used to evaluate episodes of care f or clinical studies of limited or episodic conditions and to complement cli nical expertise in developing time horizons for clinical trials.