The State of Use and Utility of Negative Controls in Pharmacoepidemiologic Studies

Uses of real-world data in drug safety and effectiveness studies are often challenged by various sources of bias. We undertook a systematic search of the published literature through September 2020 to evaluate the state of use and utility of negative controls to address bias in pharmacoepidemiologic studies. Two reviewers independently evaluated study eligibility and abstracted data. Our search identified 184 eligible studies for inclusion. Cohort studies (115, 63%) and administrative data (114, 62%) were, respectively, the most common study design and data type used. Most studies used negative control outcomes (91, 50%), and for most studies the target source of bias was unmeasured confounding (93, 51%). We identified 4 utility domains of negative controls: 1) bias detection (149, 81%), 2) bias correction (16, 9%), 3) P-value calibration (8, 4%), and 4) performance assessment of different methods used in drug safety studies (31, 17%). The most popular methodologies used were the 95% confidence interval and P-value calibration. In addition, we identified 2 reference sets with structured steps to check the causality assumption of the negative control. While negative controls are powerful tools in bias detection, we found many studies lacked checking the underlying assumptions. This article is part of a Special Collection on Pharmacoepidemiology.

Relationship of Nonsteroidal Anti-Inflammatory Drug Use During Pregnancy with Autism Spectrum Disorder and Intellectual Disability Among Offspring

Objective: This study aimed to examine the association of nonsteroidal anti-inflammatory drug (NSAID) use by pregnant women during pregnancy with autism spectrum disorder (ASD) and intellectual disability (ID) in their children among Medicaid-insured mother-child dyads. Materials and Methods: We conducted a retrospective cohort study linking multiple datasets of South Carolina for the years between 2010 and 2017, in which the main exposure variable was NSAID use during pregnancy and outcome variables were ASD only, ID only, and ASD with ID. We conducted a multinomial logistic regression analysis, controlling for identified risk factors for ASD (mother's age, race, body-mass index, preeclampsia, and gestational diabetes). Results: NSAID use during pregnancy was found to be associated with ID only in both unadjusted and adjusted analyses. Children with mothers who had NSAID prescriptions were 26% more likely to have ID in comparison with children whose mothers did not have NSAID prescriptions (odds ratio: 1.26 [1.10-1.46]). The other risk factors identified for ASD were maternal age, race, preeclampsia, smoking, low birth weight, and obesity. For ID, the risk factors were maternal age, race, smoking, birth weight, overweight, and obesity, all of which were also associated with ASD with ID, except for overweight. Conclusions: NSAID usage during pregnancy was found to be associated with ID only and not with ASD. However, more research is needed to validate the effect of NSAIDs during pregnancy on ASD and ID among children.

Prenatal Drug Exposure in Children With a History of Neuropsychiatric Care: A Nested Case-Control Study

BACKGROUND AND OBJECTIVES

Neuropsychiatric disorders in childhood after prenatal drug exposure raises concerns. Most of the published studies focused on psychotropic medications. This study investigated which prenatal medication exposure was associated with neuropsychiatric disorders in childhood.

METHODS

A case-control study, nested in the French POMME cohort, was conducted to compare prenatal medication exposure between children with a history of neuropsychiatric care (ages 0-8 years) and children in a control group. POMME included children born in Haute-Garonne to women covered by the general Health Insurance System, between 2010 and 2011 (N = 8,372). Cases were identified through: (1) reimbursement for neuropsychiatric care; (2) psychomotor development abnormalities specified on health certificates; and (3) reimbursement for methylphenidate or neuroleptics. Controls had none of these criteria. Prenatal exposure to each of the major "Anatomical Therapeutic Chemical" classes was compared between the groups. Class(es) for which there was a statistically significant difference (after Bonferroni adjustment, i.e., p < 0.0033) was(were) compared using logistic regression.

RESULTS

A total of 723 (8.6%) cases and 4,924 (58.8%) controls were identified. This study showed a statistically significant difference in prenatal exposure to nervous system drugs (excluding analgesics) between the groups [ORa: 2.12 (1.55; 2.90)]. Differences (not statistically significant at the 0.0033 threshold) were also observed for the ATC classes: Musculoskeletal, Genito-urinary System and Sex Hormones, Alimentary Tract and Anti-infectives.

CONCLUSION

Through identification of children with neuropsychiatric disorders and of their prenatal medication exposure, this study provides guidance for the assessment of long-term neuropsychiatric effects after prenatal medication exposure, without focusing on psychotropic medications.

Prenatal exposure to non-steroidal anti-inflammatory drugs and risk of attention-deficit/hyperactivity disorder: A follow-up study in the Norwegian mother, father and child cohort

PURPOSE

To estimate the association between Attention-Deficit/Hyperactivity Disorder (ADHD) in children in preschool and primary school, and prenatal exposure to non-steroidal anti-inflammatory drugs (NSAIDs) by timing and duration.

METHODS

This study was based on the Norwegian Mother, Father and Child Cohort Study linked to the Medical Birth Registry of Norway, the Norwegian Patient Registry (NPR) and the Norwegian Prescription Database (NorPD). NSAID exposure was identified by maternal self-report in pregnancy. Child diagnosis of ADHD was obtained from NPR and NorPD. Symptoms of ADHD at age 5 years were measured using Conners' Parent Rating Scale-Revised, where higher scores correspond to more symptoms. To account for time-varying exposure and confounders, marginal structural models were fitted to estimate hazard ratios and mean difference in z-scores.

RESULTS

The analyses on ADHD diagnosis and ADHD symptoms included 56 340 and 34 961 children respectively. Children exposed to NSAIDs prenatally had no increased risk of ADHD diagnosis (first trimester: HR 1.12, 95% CI 0.86;1.45, second trimester: HR 0.98, 95% CI 0.69;1.38, third trimester: HR 0.68, 95% CI 0.31; 1.46) or ADHD symptoms (first trimester: standardized mean difference 0.03, 95% CI -0.03;0.09, second trimester: standardized mean difference 0.03, 95% CI -0.04;0.11, third trimester: standardized mean difference 0.11, 95% CI -0.03; 0.25). There was no duration-response relationship for either outcome.

CONCLUSION

Though non-differential misclassification of the exposure may have attenuated results, these findings are reassuring and suggest no substantially increased risk of ADHD diagnosis or symptoms in children prenatally exposed to NSAIDs, regardless of timing or duration.

Use and validity of child neurodevelopment outcome measures in studies on prenatal exposure to psychotropic and analgesic medications - A systematic review

In recent years there has been increased attention to child neurodevelopment in studies on medication safety in pregnancy. Neurodevelopment is a multifactorial outcome that can be assessed by various assessors, using different measures. This has given rise to a debate on the validity of various measures of neurodevelopment. The aim of this review was twofold. Firstly we aimed to give an overview of studies on child neurodevelopment after prenatal exposure to central nervous system acting medications using psychotropics and analgesics as examples, giving special focus on the use and validity of outcome measures. Secondly, we aimed to give guidance on how to conduct and interpret medication safety studies with neurodevelopment outcomes. We conducted a systematic review in the MEDLINE, Embase, PsycINFO, Web of Science, Scopus, and Cochrane databases from inception to April 2019, including controlled studies on prenatal exposure to psychotropics or analgesics and child neurodevelopment, measured with standardised psychometric instruments or by diagnosis of neurodevelopmental disorder. The review management tool Covidence was used for data-extraction. Outcomes were grouped as motor skills, cognition, behaviour, emotionality, or "other". We identified 110 eligible papers (psychotropics, 82 papers, analgesics, 29 papers). A variety of neurodevelopmental outcome measures were used, including 27 different psychometric instruments administered by health care professionals, 15 different instruments completed by parents, and 13 different diagnostic categories. In 23 papers, no comments were made on the validity of the outcome measure. In conclusion, establishing neurodevelopmental safety includes assessing a wide variety of outcomes important for the child's daily functioning including motor skills, cognition, behaviour, and emotionality, with valid and reliable measures from infancy through to adolescence. Consensus is needed in the scientific community on how neurodevelopment should be assessed in medication safety in pregnancy studies. Review registration number: CRD42018086101 in the PROSPERO database.