title: Further observations on comparison of immunization coverage by lot quality assurance sampling and 30 cluster sampling.
abstract: Lot Quality Assurance Sampling (LQAS) and standard EPI methodology (30 cluster sampling) were used to evaluate immunization coverage in a Primary Health Center (PHC) where coverage levels were reported to be more than 85%. Of 27 sub-centers (lots) evaluated by LQAS, only 2 were accepted for child coverage, whereas none was accepted for tetanus toxoid (TT) coverage in mothers. LQAS data were combined to obtain an estimate of coverage in the entire population; 41% (95% CI 36-46) infants were immunized appropriately for their ages, while 42% (95% CI 37-47) of their mothers had received a second/ booster dose of TT. TT coverage in 149 contemporary mothers sampled in EPI survey was also 42% (95% CI 31-52). Although results by the two sampling methods were consistent with each other, a big gap was evident between reported coverage (in children as well as mothers) and survey results. LQAS was found to be operationally feasible, but it cost 40% more and required 2.5 times more time than the EPI survey. LQAS therefore, is not a good substitute for current EPI methodology to evaluate immunization coverage in a large administrative area. However, LQAS has potential as method to monitor health programs on a routine basis in small population sub-units, especially in areas with high and heterogeneously distributed immunization coverage.
authors.affiliation: National Institute of Communicable Diseases, New Delhi, India.
authors.forename: J
authors.initials: J
authors.lastname: Singh
authors.forename: D C
authors.initials: DC
authors.lastname: Jain
authors.forename: R S
authors.initials: RS
authors.lastname: Sharma
authors.forename: T
authors.initials: T
authors.lastname: Verghese
mesh_terms: D016000:Cluster Analysis; D005240:Feasibility Studies; D006302:Health Services Research / Q000191:economics / Q000379:methods* / Q000592:standards*; D006801:Humans; D007194:India; D007223:Infant; D011320:Primary Health Care / Q000592:standards*; D011785:Quality Assurance, Health Care / Q000379:methods*; D015203:Reproducibility of Results; D012494:Sampling Studies; D014611:Vaccination / Q000592:standards*