Evaluation of the optimal recall period for disease symptoms in home-based morbidity surveillance in rural and urban Kenya

Abstract

Background In African settings with poor access to health care, surveillance and surveys of disease burden are often done through home visits. The optimal recall period to capture data on symptoms and health utilization is unknown.Methods We collected illness data among 53 000 people during fortnightly home visits in rural and urban Kenya. Dates of cough, fever and diarrhoea in the past 2 weeks and health-seeking behaviour were recorded. Incidence rates were modelled using Poisson regression for data collected from 1 July 2006 to 30 June 2007.Results Incidence rates were higher in days 0–6 before the home visit than in days 7–13 before the home visit for all three symptoms, for the rural and urban sites, for children and adults, for self- and proxy-reported symptoms and for severe and non-severe illness in children. Recall decay was steeper in the rural than the urban sites, and for proxy- than self-reported symptoms. The daily prevalence of symptoms fell <80% of the maximum prevalence when asking about symptoms >3 days before the home visit for children and >4 days for persons ≥5 years of age. Recall of previously documented clinic visits, and prescriptions of antimalarials and antibiotics also declined by ∼7, 15 and 23% per week, respectively, in children aged <5 years, and 6, 20 and 16%, respectively, in older persons (P < 0.0001 for each decline).Conclusions A 2-week recall period underestimates true disease rates and health-care utilization. Shorter recall periods of 3 days in children and 4 days in adults would likely yield more accurate data.

Shared Sanitation and the Prevalence of Diarrhea in Young Children: Evidence from 51 Countries, 2001–2011

“…It is well documented that using a two-week recall period understates disease status, resulting in bias. Some studies [22][23][24] have suggested that a twoday or three-day recall period will minimize this bias, but Arnold and others 25 reported that one week is optimal when accounting for bias and variance. Although the two-week recall period used in the DHS is not ideal, any bias in our results should be towards the null, as long as disease misclassification is unrelated to exposure.…”

Water Filter Provision and Home-Based Filter Reinforcement Reduce Diarrhea in Kenyan HIV-Infected Adults and Their Household Members

“…The infrequent assessment of diarrhea was another limitation; participants were asked about diarrhea at every 3-month visit, whereas research has shown that the most accurate recall of morbidity events is in the last 3 days. 32 Diarrhea among household members was also ascertained from the HIV-positive participants who may or may not have been aware of diarrhea episodes among all household members, possibly resulting in underreporting of household diarrhea. Although the infrequent ascertainment of self-reported and household diarrhea by only a single household member may have been imprecise, the imprecision within a given household is unlikely to differ between time points; because the analytic comparisons were made within households, we do not believe that differential bias occurred.…”

The population-based burden of influenza-associated hospitalization in rural western Kenya, 2007–2009

“…This programme offers free, high-quality health care to participants, which promotes greater health care utilization. 16,17 The variability in findings between health facilities highlights the limitations of using one sentinel hospital to draw conclusions about the epidemiology and burden of influenza in a given district.…”

“…15 In one part of Bondo district, 25 000 people are offered free, high-quality care at Lwak Mission Hospital, including admission, as part of population-based infectious disease surveillance. 16,17 Influenza vaccination is…”