Medical Record Validation of Maternally Reported Birth Characteristics and Pregnancy-related Events: A Report from the Children's Cancer Group

Abstract

Epidemiologic studies frequently obtain exposure information through subjects' self-report (personal interview or mailed questionnaire). The authors used data from a case-control study of infant leukemia, to assess the validity and reliability of maternally reported information on birth characteristics such as birth weight, reproductive history, and medical procedures. Cases were gathered from the Children's Cancer Group, a United States and Canadian cooperative clinical trails group with approximately 100 member and affiliate institutions, during 1983-1988. Telephone interviews were completed for 302 cases and 558 matched controls. Medical records of the index pregnancy were obtained for 287 cases and 467 controls. Correlations between medical charts and maternal interview were high for birth weight (r = 0.98, kappa = 0.9) and gestational age (r = 0.86, kappa = 0.6). Mean differences between the two sources were small, -10.5 g for birth weight and -0.36 weeks for gestational age. Reproductive history and medical procedures had high to moderate reliability. Problems after delivery and pregnancy complications generally had low validity and reliability. Little evidence of differential misclassification was found. Time between delivery and interview ranged from zero to 8 years and did not greatly affect reliability. This study suggests that validity and reliability of maternally reported pregnancy and delivery information may differ with the nature of the factor of interest, but is affected little by time from birth or case-control status.

Birth weight and risk of cancer

“…Birth weights, reported by the parents and recorded at an early age, have been found to be very accurate. 57 Birth weights were furthermore recorded decades prior to and independently of a possible cancer diagnosis, making differential misclassification unlikely.…”

Repeatability of maternal report on prenatal, perinatal and early postnatal factors: findings from the IDEFICS parental questionnaire

“…Although the effect of time span on birth weight is not as pronounced, 8,9,24 studies highlight the increased inaccuracy with length of recall on data, like gestational age 25 or breastfeeding and feeding practises. 11 In our study, time span showed no effect on the concordance of maternal reports between PQ1 and PQ2.…”

“…Previous studies have investigated the reliability of maternal reports on prenatal, perinatal and on postnatal factors, and suggest that maternal recall data are reproducible for perinatal factors, for example, birth weight, gestational age or medical procedures. 8,9 In contrast, maternal reports on prenatal factors, for example, maternal weight gain during pregnancy, 10 and early infant nutrition, for example, breastfeeding or introduction of solid food, 11,12 showed only moderate agreement or inconsistency in their reliability.Several studies indicated that other factors, for example, time span or the age of the child, have an impact on the repeatability of maternal self-reports. 11,13 Generally, a shorter time span is associated with a higher repeatability of selfreports.…”

Validation of self-reported complications by bone marrow transplantation survivors

“…There are reports in the literature assessing the validity of self-reported illnesses with most studies finding 80-90% of self-reported conditions confirmed by medical records. [1][2][3][4][5][6][7] With improved therapeutic strategies the number of cancer survivors in the general population is continually increasing. 8 Many therapeutic regimens consist of combinations of radiation and/or chemotherapy, including bone marrow transplantation (BMT), which have been associated with both acute and long-term complications.…”