Indirect costs

To estimate productivity losses from varicella morbidity and premature mortality, we used the human capital approach [16]. In this approach, costs for work loss are determined using the number of days of missed work for either the provision of care for a sick child or own illness among adults. The number of days is then multiplied by the daily wage rate associated with the value of lost earning from work or the imputed economic value of housekeeping and home-care activities. We considered that the cost of work loss by parents who served as caregivers when their children had varicella was $396 per case, and the cost of work loss by adults who contracted varicella was $1476 per case [6]. Age-specific lifetime productivity loss resulting from premature death was obtained from a published study [17].