Different approaches to valuing the lost productivity of patients with migraine

Objective: To calculate and compare the human capital approach (HCA) and friction cost approach (FCA) methods for estimating the cost of lost productivity of migraineurs after the initiation of sumatriptan from a US societal perspective. Design: Secondary, retrospective analysis to a prospective observational study. Setting: A mixed-model managed care organisation in western Pennsylvania, USA. Patients: Patients with migraine using sumatriptan therapy. Interventions: Patient-reported questionnaires collected at baseline, 3 and 6 months after initiation of sumatriptan therapy. Outcome measures: The cost of lost productivity estimated with the HCA and FCA methods. Results: Of the 178 patients who completed the study, 51% were full-time employees, 13% were part-time, 18% were not working and 17% changed work status. Twenty-four percent reported a clerical or administrative position. From the HCA, the estimated total cost of lost productivity for 6 months following the initiation of sumatriptan was $US117 905 (1996 values). From the FCA, the six-month estimated total cost of lost productivity ranged from $US28 329 to $US117 905 (1996 values). Conclusions: This was the first study to retrospectively estimate lost productivity of patients with migraine using the FCA methodology. Our results demonstrate that depending on the assumptions and illustrations employed, the FCA can yield lost productivity estimates that vary greatly as a percentage of the HCA estimate. Prospective investigations are needed to better determine the components and the nature of the lost productivity for chronic episodic diseases such as migraine headache.