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Evaluation of prenatal care information on birth certificates
Author(s) -
McDermott Jeanne,
Drews Carolyn,
Green Diane,
Berg Cynthia
Publication year - 1997
Publication title -
paediatric and perinatal epidemiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.667
H-Index - 88
eISSN - 1365-3016
pISSN - 0269-5022
DOI - 10.1046/j.1365-3016.1997.d01-4.x
Subject(s) - birth certificate , medicine , prenatal care , conditional probability , epidemiology , statistics , mathematics , environmental health , population
Misclassification frequently leads to bias in epidemiological studies, and causes concern for perinatal epidemiologists interested in using birth certificates as a data source. We used a maximum likelihood method to estimate the classification probabilities (conditional probabilities that indicate the probability of classification in a particular category, given the person's true category) of two data sources for a three‐category outcome of prenatal care. The probability that women receiving adequate or inadequate care were correctly classified was estimated to be greater than 90%. The probability was much lower (< 35%) that women receiving intermediate care were correctly classified. The misclassification of women from the intermediate category resulted in poor predictive values (< 70%) of women classified as receiving either adequate or inadequate care. Because of these findings, we combined the adequate and intermediate categories to form a two‐category classification system. This revision resulted in higher positive predictive values (> 90%) with only a slightly lower classification probability (> 85%) for the combined category. We conclude that the degree of accuracy for a two‐category classification of prenatal care based upon birth certificate information is acceptable, but we question the accuracy of indices of prenatal care with more than two categories.