The impact of recall periods on reported morbidity and health seeking behavior

Between 2000 and 2002, the authors followed 1621 individuals in Delhi, India using a combination of weekly and monthly-recall health questionnaires. In 2008, they augmented these data with another 8 weeks of surveys during which households were experimentally allocated to surveys with different recall periods in the second half of the survey. This paper shows that the length of the recall period had a large impact on reported morbidity, doctor visits, time spent sick, whether at least one day of work/school was lost due to sickness, and the reported use of self-medication. The effects are more pronounced among the poor than the rich. In one example, differential recall effects across income groups reverse the sign of the gradient between doctor visits and per-capita expenditures such that the poor use health care providers more than the rich in the weekly recall surveys but less in monthly recall surveys. The authors hypothesize that illnesses -- especially among the poor -- are no longer perceived as"extraordinary events"but have become part of"normal"life. They discuss the implications of these results for health survey methodology, and the economic interpretation of sickness in poor populations.