Multiple category-lot quality assurance sampling: a new classification system with application to schistosomiasis control.
Originally a binary classifier, Lot Quality Assurance Sampling (LQAS) has proven to be a useful tool for classification of the prevalence of Schistosoma mansoni into multiple categories (≤10%, >10 and <50%, ≥50%), and semi-curtailed sampling has been shown to effectively reduce the number of o...
Published in: | PLoS Neglected Tropical Diseases |
---|---|
Main Authors: | , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Public Library of Science (PLoS)
2012
|
Subjects: | |
Online Access: | https://doi.org/10.1371/journal.pntd.0001806 https://doaj.org/article/33efe62bde8f469083ab72ee2f98edd7 |
id |
ftdoajarticles:oai:doaj.org/article:33efe62bde8f469083ab72ee2f98edd7 |
---|---|
record_format |
openpolar |
spelling |
ftdoajarticles:oai:doaj.org/article:33efe62bde8f469083ab72ee2f98edd7 2023-05-15T15:15:31+02:00 Multiple category-lot quality assurance sampling: a new classification system with application to schistosomiasis control. Casey Olives Joseph J Valadez Simon J Brooker Marcello Pagano 2012-01-01T00:00:00Z https://doi.org/10.1371/journal.pntd.0001806 https://doaj.org/article/33efe62bde8f469083ab72ee2f98edd7 EN eng Public Library of Science (PLoS) http://europepmc.org/articles/PMC3435238?pdf=render https://doaj.org/toc/1935-2727 https://doaj.org/toc/1935-2735 1935-2727 1935-2735 doi:10.1371/journal.pntd.0001806 https://doaj.org/article/33efe62bde8f469083ab72ee2f98edd7 PLoS Neglected Tropical Diseases, Vol 6, Iss 9, p e1806 (2012) Arctic medicine. Tropical medicine RC955-962 Public aspects of medicine RA1-1270 article 2012 ftdoajarticles https://doi.org/10.1371/journal.pntd.0001806 2022-12-31T08:54:37Z Originally a binary classifier, Lot Quality Assurance Sampling (LQAS) has proven to be a useful tool for classification of the prevalence of Schistosoma mansoni into multiple categories (≤10%, >10 and <50%, ≥50%), and semi-curtailed sampling has been shown to effectively reduce the number of observations needed to reach a decision. To date the statistical underpinnings for Multiple Category-LQAS (MC-LQAS) have not received full treatment. We explore the analytical properties of MC-LQAS, and validate its use for the classification of S. mansoni prevalence in multiple settings in East Africa.We outline MC-LQAS design principles and formulae for operating characteristic curves. In addition, we derive the average sample number for MC-LQAS when utilizing semi-curtailed sampling and introduce curtailed sampling in this setting. We also assess the performance of MC-LQAS designs with maximum sample sizes of n=15 and n=25 via a weighted kappa-statistic using S. mansoni data collected in 388 schools from four studies in East Africa.Overall performance of MC-LQAS classification was high (kappa-statistic of 0.87). In three of the studies, the kappa-statistic for a design with n=15 was greater than 0.75. In the fourth study, where these designs performed poorly (kappa-statistic less than 0.50), the majority of observations fell in regions where potential error is known to be high. Employment of semi-curtailed and curtailed sampling further reduced the sample size by as many as 0.5 and 3.5 observations per school, respectively, without increasing classification error.This work provides the needed analytics to understand the properties of MC-LQAS for assessing the prevalance of S. mansoni and shows that in most settings a sample size of 15 children provides a reliable classification of schools. Article in Journal/Newspaper Arctic Directory of Open Access Journals: DOAJ Articles Arctic PLoS Neglected Tropical Diseases 6 9 e1806 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
Arctic medicine. Tropical medicine RC955-962 Public aspects of medicine RA1-1270 |
spellingShingle |
Arctic medicine. Tropical medicine RC955-962 Public aspects of medicine RA1-1270 Casey Olives Joseph J Valadez Simon J Brooker Marcello Pagano Multiple category-lot quality assurance sampling: a new classification system with application to schistosomiasis control. |
topic_facet |
Arctic medicine. Tropical medicine RC955-962 Public aspects of medicine RA1-1270 |
description |
Originally a binary classifier, Lot Quality Assurance Sampling (LQAS) has proven to be a useful tool for classification of the prevalence of Schistosoma mansoni into multiple categories (≤10%, >10 and <50%, ≥50%), and semi-curtailed sampling has been shown to effectively reduce the number of observations needed to reach a decision. To date the statistical underpinnings for Multiple Category-LQAS (MC-LQAS) have not received full treatment. We explore the analytical properties of MC-LQAS, and validate its use for the classification of S. mansoni prevalence in multiple settings in East Africa.We outline MC-LQAS design principles and formulae for operating characteristic curves. In addition, we derive the average sample number for MC-LQAS when utilizing semi-curtailed sampling and introduce curtailed sampling in this setting. We also assess the performance of MC-LQAS designs with maximum sample sizes of n=15 and n=25 via a weighted kappa-statistic using S. mansoni data collected in 388 schools from four studies in East Africa.Overall performance of MC-LQAS classification was high (kappa-statistic of 0.87). In three of the studies, the kappa-statistic for a design with n=15 was greater than 0.75. In the fourth study, where these designs performed poorly (kappa-statistic less than 0.50), the majority of observations fell in regions where potential error is known to be high. Employment of semi-curtailed and curtailed sampling further reduced the sample size by as many as 0.5 and 3.5 observations per school, respectively, without increasing classification error.This work provides the needed analytics to understand the properties of MC-LQAS for assessing the prevalance of S. mansoni and shows that in most settings a sample size of 15 children provides a reliable classification of schools. |
format |
Article in Journal/Newspaper |
author |
Casey Olives Joseph J Valadez Simon J Brooker Marcello Pagano |
author_facet |
Casey Olives Joseph J Valadez Simon J Brooker Marcello Pagano |
author_sort |
Casey Olives |
title |
Multiple category-lot quality assurance sampling: a new classification system with application to schistosomiasis control. |
title_short |
Multiple category-lot quality assurance sampling: a new classification system with application to schistosomiasis control. |
title_full |
Multiple category-lot quality assurance sampling: a new classification system with application to schistosomiasis control. |
title_fullStr |
Multiple category-lot quality assurance sampling: a new classification system with application to schistosomiasis control. |
title_full_unstemmed |
Multiple category-lot quality assurance sampling: a new classification system with application to schistosomiasis control. |
title_sort |
multiple category-lot quality assurance sampling: a new classification system with application to schistosomiasis control. |
publisher |
Public Library of Science (PLoS) |
publishDate |
2012 |
url |
https://doi.org/10.1371/journal.pntd.0001806 https://doaj.org/article/33efe62bde8f469083ab72ee2f98edd7 |
geographic |
Arctic |
geographic_facet |
Arctic |
genre |
Arctic |
genre_facet |
Arctic |
op_source |
PLoS Neglected Tropical Diseases, Vol 6, Iss 9, p e1806 (2012) |
op_relation |
http://europepmc.org/articles/PMC3435238?pdf=render https://doaj.org/toc/1935-2727 https://doaj.org/toc/1935-2735 1935-2727 1935-2735 doi:10.1371/journal.pntd.0001806 https://doaj.org/article/33efe62bde8f469083ab72ee2f98edd7 |
op_doi |
https://doi.org/10.1371/journal.pntd.0001806 |
container_title |
PLoS Neglected Tropical Diseases |
container_volume |
6 |
container_issue |
9 |
container_start_page |
e1806 |
_version_ |
1766345891499737088 |