Study | Country Study period Study design |
Data source | Exposure definition | Non-exposure definition | Exposition period | Sample size (exposed/unexposed) Or (case / control) |
Remarks | Risk of bias |
---|---|---|---|---|---|---|---|---|
Källén 2013 |
Swedish 1996 - 2011 population based cohort retrospective |
The Swedish Medical Birth Register, the Swedish Register of Prescribed Drugs, the Register of Birth Defect and Hospital Discharge Register. | Infants whose mothers used flunitrazepam in early pregnancy. (This is a subgroup of exposure among the whole exposed group considered in the study). |
unexposed (general population or NOS)
Infants in population whose mothers used at least one of a central nervous system active drugs (less than 3%) or weren't exposed in early pregnancy. |
early pregnancy | 184 / 1575847 | Follow-up period known thanks to author's email reply. | |
At the midwife interview at the first antenatal care visit, the woman was asked if she had used any drugs since she became pregnant. Or determined by the use of the Swedish Register of Prescribed Drugs (since 2006). | ||||||||
Meng a (Controls unexposed, sibling) 2023 |
Taiwan 2004 - 2018 population based cohort retrospective |
A nationwide, population-based cohort study in Taiwan using three data sources: Taiwan’s National Birth Certificate Application database, the National Health Insurance database, and the Maternal and Child Health Database. | Sibling with at least one Flunitrazepam prescription received by the mother during early pregnancy (the first 20 weeks of pregnancy). |
sibling
Discordant matched sibling without benzodiazepine or Z-hypnotic prescriptions from 30 days before the date of the estimated last menstrual period to the end of the 20th week of pregnancy. |
early pregnancy | -9 / -9 | Number of exposures not provided (authors provided number of Exposure discordant pairs and number of Case discordant pairs). | |
The National Health Insurance (NHI) database that comprises anonymised health insurance claims for visits, procedures, and prescriptions for more than 99% of the population in Taiwan (about 23 million). | ||||||||
Meng a (Controls unexposed, sick) 2023 |
Taiwan 2004 - 2018 population based cohort retrospective |
A nationwide, population-based cohort study in Taiwan using three data sources: Taiwan’s National Birth Certificate Application database, the National Health Insurance database, and the Maternal and Child Health Database. | At least one Flunitrazepam prescription received by a mother during early pregnancy (the first 20 weeks of pregnancy). |
unexposed, sick
Pregnant women with no benzodiazepine or Z-hypnotic prescriptions from 30 days before the date of the estimated last menstrual period to the end of the 20th week of pregnancy. |
early pregnancy | 2612 / 2766866 | Use of results obtained with PS-FSW because more exposures, with a sick control group and sensitivity analyses (sibling control study, and paternal negative control design) that obtained similar results. | |
The National Health Insurance (NHI) database that comprises anonymised health insurance claims for visits, procedures, and prescriptions for more than 99% of the population in Taiwan (about 23 million). | ||||||||
Noh 2022 |
South Korea 2011 - 2018 population based cohort retrospective |
A nationwide retrospective cohort study using healthcare data retrieved from the Health Insurance Review and Assessment Service (HIRA) database. | Pregnant women who filled at least Flunitrazepam prescription during the first trimester (first 90 days of pregnancy). |
unexposed, sick
Pregnant women who were not prescribed any benzodiazepine from 3 months before the last menstrual period to the end of the first trimester (with similar psychiatric conditions after propensity score). |
1st trimester | 824 / 3053381 | Propensity scored adjusted for indications and led to an unexposed cohort with similar psychiatric conditions => considered as unexposed, sick control groups. | |
The Health Insurance Review and Assessment Service (HIRA) database that comprises notably healthcare utilization (e.g., drug prescription and medical procedure). |
Study | Country Study period Study design |
Data source | Case | Control | Exposition | Exposition period | Sample size (exposed/unexposed) Or (case / control) |
Remarks | Risk of bias |
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Risk of bias: : NA; : low; : moderate; : serious; : critical; : unclear;