CHALLENGES IN MEASURING MEASLES CASE FATALITY RATIOS IN SETTINGS WITHOUT VITAL REGISTRATION.

Tuesday, 11th of June 2013

[source]Emerging Themes in Epidemiology[|source]

Full text documentation of a retrospective study method of determining measles case fatality ratios (CFR) in a setting without vital registration systems. Challenges not withstanding, the approach used is simple, avoids long recall periods and thus biases, had quality assurance procedures and could easily be translate into many countries without vital registration system. More details on the approach are available at: http://www.ete-online.com/content/pdf/1742-7622-7-4.pdf

Abstract

Measles, a highly infectious vaccine-preventable viral disease, is potentially fatal. Historically, measles case-fatality ratios (CFRs) have been reported to vary from 0.1% in the developed world to as high as 30% in emergency settings. Estimates of the global burden of mortality from measles, critical to prioritizing measles vaccination among other health interventions, are highly sensitive to the CFR estimates used in modelling; however, due to the lack of reliable, up-to-date data, considerable debate exists as to what CFR estimates are appropriate to use. To determine current measles CFRs in high-burden settings without vital registration we have conducted six retrospective measles mortality studies in such settings. This paper examines the methodological challenges of this work and our solutions to these challenges, including the integration of lessons from retrospective all-cause mortality studies into CFR studies, approaches to laboratory confirmation of outbreaks, and means of obtaining a representative sample of case-patients. Our experiences are relevant to those conducting retrospective CFR studies for measles or other diseases, and to those interested in all-cause mortality studies.