Improving tuberculosis case detection rate with a lay informant questionnaire: an experience from the Lao People's Democratic Republic

Abstract

Problem In many countries, the tuberculosis (TB) annual case detection rate is below the target of 70%. In the Lao People's Democratic Republic in 2005, it did not exceed 55%. Approach The DOTS strategy promotes passive case detection of TB. In order to increase the detection rate, we validated a questionnaire targeting lay informants at village level to notify patients with chronic cough and assessed the relevance for TB case-finding. A three-item questionnaire was sent through the district health departments to all villages in six districts in six provinces. The village headmen were asked to notify chronic cough patients. Answers were validated in a door-to-door survey (20 villages/district). In a sub-sample (four villages/district) all confirmed patients were screened for TB and paragonimiasis. Local setting Attapeu, Luang Namtha, Luang Prabang, Saravane, Savanakhet and Vientiane provinces in the Lao People's Democratic Republic. Relevant changes Lay informant questionnaires sent from district health offices to villages are cost-effective and foster interaction between the health services and remote and underserved communities. Although the correct detection of patients is highly dependent on direct respondents, a substantial number of new TB and paragonimiasis cases were consistently diagnosed in chronic cough patients. Lessons learned Out of 456 questionnaires, 295 were returned (65%). Return rates were highly variable between districts (48-87%), questionnaires' sensitivity (56-98%), positive predictive value (34-88%) and correlation between number of notified and confirmed patients (r: 0.26-0.78). In sub-sampled villages (13 541 population) 19 (5.1%) TB and 26 (7.0%) paragonimiasis cases were detected in 374 chronic cough patients. This quick questionnaire approach proved motivating for district authorities and village key informants, although no incentives were provided. The highly operator-dependent approach yielded a consistent detection rate of TB and paragonimiasis cases. This approach brings health services and populations in need in close contact, which is particularly crucial in remote and underserved areas.

Determinants of TB Case Detection in Nigeria: A Survey

“…It is very good that people can readily identify a 'potential' TB infectious case using chronic cough as a marker, although about half of the population in the survey either didn't know if chronic cough could be used as a marker for identifying TB cases or disagreed completely with the idea that chronic cough could be a marker for someone with tuberculosis. However the study in Odermatt et al (2007) showed that actively identifying patients with chronic cough in the community has the potential to improve case detection rates as shown in the study conducted in the Lao People's Democratic Republic. The study suggested that rapid, low-cost and easily applicable approaches are needed for improving detection rates of TB in the locality.…”

“…Basically the objective of the study in Odermatt et al (2007) was to validate a rapid and low-cost questionnaire to identify patients with chronic cough and assess its relevance in TB case detection in six provinces. The result from the study in Odermatt et al (2007) showed that the lay informant questionnaire method performed moderately. It allowed the detection of several hitherto undiagnosed smear-positive TB cases.…”

“…In fact in one of the selected province, nine new TB cases were diagnosed, yielding an incidence rate of 342/100,000, which is three times higher than the national incidence rate. Hence being able to identify a TB infectious case using chronic cough that lasts for more than two weeks as an important marker could help in increasing case detection in Nigeria as many in the population are ready to use such a means of identifying TB cases Odermatt et al (2007).…”

“…This implies that about half of the population may not be able to use chronic cough as a marker for identifying a likely potential TB case. A study in Odermatt et al (2007) showed the impressive increase in case detection through the informal use of chronic cough as an identifying characteristic of TB cases in the Lao People's Democratic Republic.…”

Rapid Identification of Paragonimiasis Foci by Lay Informants in Lao People's Democratic Republic

“…They should be detected also by lay-person. The reasons for this underreporting are not clear but we observed it also in a larger study in six provinces on tuberculosis cases detection using the same question of chronic cough [18]. We suspect that the highly prevalent symptom of chronic cough is very unspecific and often regarded as banal or even “normal”, and therefore not perceived as worthy to notify.…”