PMID- 23378151 OWN - NLM STAT- MEDLINE DCOM- 20130923 LR - 20211021 IS - 1464-3685 (Electronic) IS - 0300-5771 (Print) IS - 0300-5771 (Linking) VI - 42 IP - 1 DP - 2013 Feb TI - Choosing a design to fit the situation: how to improve specificity and positive predictive values using Bayesian lot quality assurance sampling. PG - 346-55 LID - 10.1093/ije/dys230 [doi] AB - BACKGROUND: Lot Quality Assurance Sampling (LQAS) is a provably useful tool for monitoring health programmes. Although LQAS ensures acceptable Producer and Consumer risks, the literature alleges that the method suffers from poor specificity and positive predictive values (PPVs). We suggest that poor LQAS performance is due, in part, to variation in the true underlying distribution. However, until now the role of the underlying distribution in expected performance has not been adequately examined. METHODS: We present Bayesian-LQAS (B-LQAS), an approach to incorporating prior information into the choice of the LQAS sample size and decision rule, and explore its properties through a numerical study. Additionally, we analyse vaccination coverage data from UNICEF's State of the World's Children in 1968-1989 and 2008 to exemplify the performance of LQAS and B-LQAS. RESULTS: Results of our numerical study show that the choice of LQAS sample size and decision rule is sensitive to the distribution of prior information, as well as to individual beliefs about the importance of correct classification. Application of the B-LQAS approach to the UNICEF data improves specificity and PPV in both time periods (1968-1989 and 2008) with minimal reductions in sensitivity and negative predictive value. CONCLUSIONS: LQAS is shown to be a robust tool that is not necessarily prone to poor specificity and PPV as previously alleged. In situations where prior or historical data are available, B-LQAS can lead to improvements in expected performance. FAU - Olives, Casey AU - Olives C AD - Department of Biostatistics, University of Washington, Seattle, WA, USA. colives@uw.edu FAU - Pagano, Marcello AU - Pagano M LA - eng PT - Journal Article DEP - 20130201 PL - England TA - Int J Epidemiol JT - International journal of epidemiology JID - 7802871 RN - 0 (Measles Vaccine) SB - IM MH - *Bayes Theorem MH - Child MH - Humans MH - Immunization/*statistics & numerical data MH - *Lot Quality Assurance Sampling MH - Measles Vaccine/administration & dosage MH - Population Surveillance MH - Predictive Value of Tests MH - Program Evaluation/methods MH - Quality Assurance, Health Care/methods MH - Research Design MH - Sensitivity and Specificity MH - United Nations PMC - PMC3600627 EDAT- 2013/02/05 06:00 MHDA- 2013/09/24 06:00 PMCR- 2014/02/01 CRDT- 2013/02/05 06:00 PHST- 2013/02/05 06:00 [entrez] PHST- 2013/02/05 06:00 [pubmed] PHST- 2013/09/24 06:00 [medline] PHST- 2014/02/01 00:00 [pmc-release] AID - dys230 [pii] AID - 10.1093/ije/dys230 [doi] PST - ppublish SO - Int J Epidemiol. 2013 Feb;42(1):346-55. doi: 10.1093/ije/dys230. Epub 2013 Feb 1.