Users Online: 166 Home Print this page Email this page Small font sizeDefault font sizeIncrease font size


Home About us Editorial board Search Ahead of print Current issue Archives Submit article Instructions Subscribe Contacts Login 
Year : 2001  |  Volume : 45  |  Issue : 1  |  Page : 14-9

Estimating true burden of disease detected by screening tests of varying validity.

Department of PSM, Institute of Medical Sciences, Banaras Hindu University, Varanasi-221005, U.P., India

Correspondence Address:
R N Mishra
Department of PSM, Institute of Medical Sciences, Banaras Hindu University, Varanasi-221005, U.P., India

Login to access the Email id

Source of Support: None, Conflict of Interest: None

PMID: 11917314

Rights and PermissionsRights and Permissions

Timely and accurate information on disease load is essential for planning health programs. Unfortunately, complexity, cost and need of skilled personnel limit the use of screening tools of high validity in developing countries. The disease load estimated with tools of low validity differs considerably from true disease load, particularly for diseases of extreme levels of prevalence/incidence. A tool of 70% sensitivity and specificity may yield a prevalence/incidence rate of 34% (CI: 32.23-35.67%) for a disease whose true rate is only 10.0% (CI: 8.94-11.06%). We proposed a procedure to derive the true estimate in such cases, based on the concepts of sensitivity and specificity of a diagnostic/screening test. It is applied on two sets of real data--one pertaining to incidence rate of low birth weight (LBW) and the other to prevalence rate of obesity--where multiple screening tests of varying validity were used to estimate the magnitude. Different screening tests yielded widely varying incidence/prevalence rates of LBW/obesity. The prevalence/incidence rates derived by using the proposed estimation procedure are similar and close to the true estimate obtained by screening tests considered as gold standard. Further, sample size determined on the basis of the results of a tool of low validity may be either larger or smaller than the required sample size. Estimation of true disease load enables determination of correct sample size, thus improving the precision of the estimate and, in some instances, reducing the cost of investigation.

[PDF Not available]*
Print this article     Email this article
 Next article
 Previous article
 Table of Contents

 Similar in PUBMED
   Search Pubmed for
   Search in Google Scholar for
 Related articles
 Citation Manager
 Access Statistics
 Reader Comments
 Email Alert *
 Add to My List *
 * Requires registration (Free)

 Article Access Statistics
    PDF Downloaded0    
    Comments [Add]    
    Cited by others 1    

Recommend this journal