International Emergency Medicine
Background: Attrition in pediatric trials can be a significant problem. A review of pediatric trials demonstrated a mean initial attrition rate of 20%. This is likely higher in developing countries due to cost, transportation, and telecommunication limitations. Our objective is to determine if a telephone follow-up intervention during a pediatric trial in a developing country can produce adequate follow-up.
Methods: The parent study is a single-blinded, prospective, observational study in Siem Reap, Cambodia. Children 3 months through 16 years with suspected dengue fever were eligible and enrolled subjects underwent bedside ultrasound. Caretakers provided up to two mobile telephone numbers and were informed of plans for a follow-up interview 7-10 days after enrollment. The interviews were conducted by nursing staff fluent in the native language but blinded to study data. Attempts were made on at least three consecutive days before categorization as lost to follow-up. Data was analyzed using descriptive statistics, and post-hoc analysis between sub-groups was performed using Fisher’s exact test or the Marascuilo procedure for comparing multiple proportions.
Results: A total of 155 patients were enrolled during a nation-wide dengue outbreak. This represented 7.9% of children presenting to the outpatient department for evaluation of an acute illness during the 14-day study period. Zero, one, or two telephone numbers were provided by 1.9%, 72.3%, and 25.8% of the subjects, respectively. On average, subjects were contacted 8 days after enrollment and required 1.1 calls. Overall, 10.3% of subjects were lost to follow-up. Difference in clinical severity of dengue, presence of warning signs as per WHO guidelines, at time of presentation was not statistically different between successful or failed follow-up subgroups (49% vs 56.3%, p = 0.8). Analysis of outcomes based on the quantity of phone numbers provided demonstrated that increasing numbers correlated with improved follow-up (0%, 89.3%, 97.5%, p = 0.0001).
Conclusions: Reasonable follow-up rates can be achieved in a pediatric trial in a developing country by utilizing structured, mobile telephone interviews conducted by local staff. In this setting, obtaining additional phone numbers improves follow-up. Similar strategies could be considered by clinicians and researchers in resource-limited settings.