Methodological considerations in assessing the effectiveness of antidepressant medication continuation during pregnancy using administrative data

Antidepressant continuation and adherence in pregnancy, and risk of antenatal hospitalization for unipolar major depressive and/or anxiety disorders

BACKGROUND

Knowledge about the effectiveness of antidepressants in pregnancy is limited. We aimed to evaluate the association of antidepressant continuation in pregnancy and adherence with the risk of antenatal hospitalization for depression/anxiety.

METHODS

In a population-based study based on the healthcare databases of the Lombardy region, Italy (2010-2020), we included 17,033 live-birth pregnancies within 16,091 women with antidepressant use before pregnancy. Antidepressant exposure was classified as continued in pregnancy versus discontinued proximal to pregnancy. Outcome measure was antenatal hospitalization for depression/anxiety. Propensity score matching analysis was performed to control for measured confounding. Stratification by pre-pregnancy antidepressant adherence based on the proportion of days covered (PDC) with antidepressants served to address confounding by disease severity. We applied 60 days lag-time for antidepressant exposure to minimize the risk of protopathic bias.

RESULTS

There were 362 (2.1 %) antenatal hospitalizations for depression/anxiety. Among the matched pairs, the cumulative incidence was 3.5 (continued antidepressant) versus 2.1 (discontinued antidepressant) per 1000 person-months, yielding a hazard ratio (HR) of 1.76 (95 % confidence interval (CI): 1.34-2.33)). The HR declined to the null (1.02, 95 % CI: 0.62-1.69) in the stratified analysis of pregnancies with moderate-high adherence pre-pregnancy. Moderate-high adherence in pregnancy was associated with 85 % greater risk of the antenatal outcome, but the HR decreased with the 60 days lag-time (HR: 1.40, 95 % CI: 0.79-2.50).

LIMITATIONS

Lack of information regarding antidepressant dosage.

CONCLUSION

We found no difference in risk for antenatal hospitalization for depression/anxiety with antidepressant continuation or higher adherence in pregnancy, relative to discontinuation or lower adherence.

Antidepressants in pregnancy: applying causal epidemiological methods to understand service-use outcomes in women and long-term neurodevelopmental outcomes in exposed children

Background

Antidepressants are commonly prescribed during pregnancy, despite a lack of evidence from randomised trials on the benefits or risks. Some studies have reported associations of antidepressants during pregnancy with adverse offspring neurodevelopment, but whether or not such associations are causal is unclear.

Objectives

To study the associations of antidepressants for depression in pregnancy with outcomes using multiple methods to strengthen causal inference.

Design

This was an observational cohort design using multiple methods to strengthen causal inference, including multivariable regression, propensity score matching, instrumental variable analysis, negative control exposures, comparison across indications and exposure discordant pregnancies analysis.

Setting

This took place in UK general practice.

Participants

Participants were pregnant women with depression.

Interventions

The interventions were initiation of antidepressants in pregnancy compared with no initiation, and continuation of antidepressants in pregnancy compared with discontinuation.

Main outcome measures

The maternal outcome measures were the use of primary care and secondary mental health services during pregnancy, and during four 6-month follow-up periods up to 24 months after pregnancy, and antidepressant prescription status 24 months following pregnancy. The child outcome measures were diagnosis of autism, diagnosis of attention deficit hyperactivity disorder and intellectual disability.

Data sources

UK Clinical Practice Research Datalink.

Results

Data on 80,103 pregnancies were used to study maternal primary care outcomes and were linked to 34,274 children with at least 4-year follow-up for neurodevelopmental outcomes. Women who initiated or continued antidepressants during pregnancy were more likely to have contact with primary and secondary health-care services during and after pregnancy and more likely to be prescribed an antidepressant 2 years following the end of pregnancy than women who did not initiate or continue antidepressants during pregnancy (odds ratioinitiation 2.16, 95% confidence interval 1.95 to 2.39; odds ratiocontinuation 2.40, 95% confidence interval 2.27 to 2.53). There was little evidence for any substantial association with autism (odds ratiomultivariableregression 1.10, 95% confidence interval 0.90 to 1.35; odds ratiopropensityscore 1.06, 95% confidence interval 0.84 to 1.32), attention deficit hyperactivity disorder (odds ratiomultivariableregression 1.02, 95% confidence interval 0.80 to 1.29; odds ratiopropensityscore 0.97, 95% confidence interval 0.75 to 1.25) or intellectual disability (odds ratiomultivariableregression 0.81, 95% confidence interval 0.55 to 1.19; odds ratiopropensityscore 0.89, 95% confidence interval 0.61 to 1.31) in children of women who continued antidepressants compared with those who discontinued antidepressants. There was inconsistent evidence of an association between initiation of antidepressants in pregnancy and diagnosis of autism in offspring (odds ratiomultivariableregression 1.23, 95% confidence interval 0.85 to 1.78; odds ratiopropensityscore 1.64, 95% confidence interval 1.01 to 2.66) but not attention deficit hyperactivity disorder or intellectual disability; however, but results were imprecise owing to smaller numbers.

Limitations

Several causal-inference analyses lacked precision owing to limited numbers. In addition, adherence to the prescribed treatment was not measured.

Conclusions

Women prescribed antidepressants during pregnancy had greater service use during and after pregnancy than those not prescribed antidepressants. The evidence against any substantial association with autism, attention deficit hyperactivity disorder or intellectual disability in the children of women who continued compared with those who discontinued antidepressants in pregnancy is reassuring. Potential association of initiation of antidepressants during pregnancy with offspring autism needs further investigation.

Future work

Further research on larger samples could increase the robustness and precision of these findings. These methods applied could be a template for future pharmaco-epidemiological investigation of other pregnancy-related prescribing safety concerns.

Funding

This project was funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment programme (15/80/19) and will be published in full in Health Technology Assessment; Vol. 27, No. 15. See the NIHR Journals Library website for further project information.

Timing of Antidepressant Discontinuation During Pregnancy and Postpartum Psychiatric Outcomes in Denmark and Norway

Importance

Approximately one-half of women treated for affective disorders discontinue antidepressant use during pregnancy, yet this discontinuation could lead to relapse post partum.

Objective

To investigate the associations between longitudinal antidepressant fill trajectories during pregnancy and postpartum psychiatric outcomes.

Design, Setting, and Participants

This cohort study used nationwide registers in Denmark and Norway. The sample included 41 475 live-born singleton pregnancies in Denmark (1997-2016) and 16 459 in Norway (2009-2018) for women who filled at least 1 antidepressant prescription within 6 months before pregnancy.

Exposures

Antidepressant prescription fills were obtained from the prescription registers. Antidepressant treatment during pregnancy was modeled using the k-means longitudinal method.

Main Outcomes and Measures

Initiation of psycholeptics, psychiatric emergencies, or records of self-harm within 1 year post partum. Between April 1 and October 30, 2022, hazard ratios (HRs) for each psychiatric outcome were estimated using Cox proportional hazards regression models. Inverse probability of treatment weighting was used to control for confounding. Country-specific HRs were pooled using random-effects meta-analytic models.

Results

Among 57 934 pregnancies (mean [SD] maternal age, 30.7 [5.3] years in Denmark and 29.9 [5.5] years in Norway), 4 antidepressant fill trajectories were identified: early discontinuers (31.3% and 30.4% of the included pregnancies in Denmark and Norway, respectively), late discontinuers (previously stable users) (21.5% and 27.8%), late discontinuers (short-term users) (15.9% and 18.4%), and continuers (31.3% and 23.4%). Early discontinuers and late discontinuers (short-term users) had a lower probability of initiating psycholeptics and having postpartum psychiatric emergencies vs continuers. A moderately increased probability of initiation of psycholeptics was found among late discontinuers (previously stable users) vs continuers (HR, 1.13; 95% CI, 1.03-1.24). This increase in late discontinuers (previously stable users) was more pronounced among women with previous affective disorders (HR, 1.28; 95% CI, 1.12-1.46). No association between antidepressant fill trajectories and postpartum self-harm risk was found.

Conclusions and Relevance

Based on pooled data from Denmark and Norway, a moderately elevated probability of initiation of psycholeptics in late discontinuers (previously stable users) vs continuers was found. These findings suggest that women with severe mental illness who are currently on stable treatment may benefit from continuing antidepressant treatment and personalized treatment counseling during pregnancy.

Psychiatric visits during the postpartum year in women with eating disorders who continue or discontinue antidepressant treatment in pregnancy

OBJECTIVE

To determine the association between continued antidepressant use in pregnancy and postpartum psychiatric visits for eating (ED) or mood/anxiety disorders in women with preexisting ED.

METHOD

Using Danish health registry data (1998-2015), we identified 3529 pregnancies in women with ED prepregnancy: (i) 564 with continued antidepressant use before and during pregnancy; (ii) 778 with discontinued antidepressants before pregnancy; (iii) 2137 unexposed. Outpatient and inpatient postpartum visits for an ED or a mood/anxiety disorder constituted the outcome measures. We estimated hazard ratios (HRs) and 95% confidence intervals (CI) using Cox regression with inverse probability of treatment weighting, and performed stratified analyses by antidepressant prescription filling in the first 3 months postpartum.

RESULTS

The weighted cumulative incidence for an ED visit at end of follow-up was 4.5% (continued) and 4.8% (discontinued). We found no association between continued antidepressant and postpartum ED visit, relative to discontinued (HR: 0.89, 95% CI: 0.52-1.52). The HR for postpartum mood/anxiety disorder visit was 1.27 (95% CI: 0.68-2.36) with continued antidepressants versus discontinued but decreased if more than two antidepressant prescriptions were refilled. Continued antidepressant use was associated with a 57% reduced likelihood of a postpartum ED visit versus discontinued use in pregnancies with antidepressant prescription refills in the early postpartum.

CONCLUSION

Among women with preexisting ED, there was no association between continued antidepressant use during pregnancy and the likelihood of postpartum psychiatric visits, relative to discontinued antidepressants before pregnancy. Continuation of treatment into the early postpartum is associated with reduced likelihood of postpartum ED visit.

PUBLIC SIGNIFICANCE

Based on data from the Danish registries, we identified 3529 pregnancies among women with preexisting eating disorders before pregnancy. Women with continued antidepressant treatment both before and during pregnancy did not have a lower probability of having postpartum psychiatric visits for an eating disorder or for mood/anxiety disorders (often coexisting with eating disorders), relative to those who discontinued antidepressants before pregnancy. Further continuation of antidepressant treatment into the early postpartum is associated with improved maternal postpartum outcomes. However, residual confounding by disease severity limits confidence in this conclusion.

Antidepressant Fill and Dose Trajectories in Pregnant Women with Depression and/or Anxiety: A Norwegian Registry Linkage Study

Background

Few studies investigated longitudinal antidepressant exposure during pregnancy and included dosage in the assessment.

Methods

We conducted a nationwide, registry-linkage study in Norway using data on antidepressant prescription fills in pregnancies lasting ≥32 weeks in women with a delivery between 2009 and 2018 who had a depression/anxiety diagnosis and antidepressant fills prior to pregnancy. Information on antidepressant exposure by week (measured by filled prescriptions) and prescribed average daily dose was used in longitudinal k-means trajectory modelling for a 108-week time window from six months prior to pregnancy to one year after delivery. Factors associated with trajectory group membership were examined using multinomial logistic regression models.

Results

We included 8,460 pregnancies in 8,092 women. Four antidepressant fill trajectories were identified based on filled antidepressant prescriptions: two distinct discontinuing patterns, one at around the start of pregnancy (30.4%) and one around the end of pregnancy (33.8%); one continuing pattern (20.6%); and one interrupting pattern (15.2%). Using average usual daily dose, we identified low dose discontinuing (60.3%), medium dose reducing (20.6%) and high dose continuing (15.2%) patterns. The multinomial logistic regressions showed that the fill trajectory group membership was strongly associated with: antidepressant type and dose prior to pregnancy and co-medication prior to pregnancy, maternal age, marital status, parity, previous pregnancy loss, and pregnancy planning.

Conclusion

Longitudinal trajectory modelling revealed distinct antidepressant fill and dosage patterns in the period around pregnancy. Knowledge about factors associated with utilization trajectories might be useful for health-care personnel counselling women about antidepressant use in pregnancy.

Selective Serotonin Reuptake Inhibitors (SSRIs) in Pregnancy: An Updated Review on Risks to Mother, Fetus, and Child

PURPOSE OF REVIEW

To provide an updated summary and appraisal of work from 2019 to 2022 examining risks of selective serotonin reuptake inhibitor (SSRI) use in pregnancy.

RECENT FINDINGS

Perinatal SSRI exposure does not increase risk of major malformations or gestational diabetes after accounting for underlying maternal illness. SSRIs are associated with small increase in risk of pre-eclampsia, postpartum hemorrhage, preterm delivery, persistent pulmonary hypertension of the newborn, and neonatal intensive care unit admissions, though absolute risk of these outcomes is low. While data suggests no increased risk of neurodevelopmental disorders in offspring, mixed evidence indicates increased risk of adverse cognitive outcomes and affective disorders. Recent evidence suggest low absolute risk of clinically relevant negative outcomes with perinatal SSRI exposure when compared to untreated perinatal depression. However, study design and ability to control for confounding remains an ongoing research challenge, highlighting need for ongoing rigorous study design and analysis.

Treatment of Peripartum Depression with Antidepressants and Other Psychotropic Medications: A Synthesis of Clinical Practice Guidelines in Europe

This study examined (1) the availability and content of national CPGs for treatment of peripartum depression, including comorbid anxiety, with antidepressants and other psychotropics across Europe and (2) antidepressant and other psychotropic utilization data as an indicator of prescribers' compliance to the guidelines. We conducted a search using Medline and the Guidelines International Network database, combined with direct e-mail contact with national Riseup-PPD COST ACTION members and researchers within psychiatry. Of the 48 European countries examined, we screened 41 records and included 14 of them for full-text evaluation. After exclusion of ineligible and duplicate records, we included 12 CPGs. Multiple CPGs recommend antidepressant initiation or continuation based on maternal disease severity, non-response to first-line non-pharmacological interventions, and after risk-benefit assessment. Advice on treatment of comorbid anxiety is largely missing or unspecific. Antidepressant dispensing data suggest general prescribers' compliance with the preferred substances of the CPG, although country-specific differences were noted. To conclude, there is an urgent need for harmonized, up-to-date CPGs for pharmacological management of peripartum depression and comorbid anxiety in Europe. The recommendations need to be informed by the latest available evidence so that healthcare providers and women can make informed, evidence-based decisions about treatment choices.

Antidepressant discontinuation before or during pregnancy and risk of psychiatric emergency in Denmark: A population-based propensity score-matched cohort study

BACKGROUND

Women prescribed antidepressants face the dilemma of whether or not to continue their treatment during pregnancy. Currently, limited evidence is available on the efficacy of continuing versus discontinuing antidepressant treatment during pregnancy to aid their decision. We aimed to estimate whether antidepressant discontinuation before or during pregnancy was associated with an increased risk of psychiatric emergency (ascertained by psychiatric admission or emergency room visit), a proxy measure of severe exacerbation of symptoms/mental health crisis.

METHODS AND FINDINGS

We carried out a propensity score-matched cohort study of women who gave birth to live-born singletons between January 1, 1997 and June 30, 2016 in Denmark and who redeemed an antidepressant prescription in the 90 days before the pregnancy, identified by Anatomical Therapeutic Chemical (ATC) code N06A. We constructed 2 matched cohorts, matching each woman who discontinued antidepressants before pregnancy (N = 2,669) or during pregnancy (N = 5,467) to one who continued antidepressants based on propensity scores. Maternal characteristics and variables related to disease severity were used to generate the propensity scores in logistic regression models. We estimated hazard ratios (HRs) of psychiatric emergency in the perinatal period (pregnancy and 6 months postpartum) using stratified Cox regression. Psychiatric emergencies were observed in 76 women who discontinued antidepressants before pregnancy and 91 women who continued. There was no evidence of higher risk of psychiatric emergency among women who discontinued antidepressants before pregnancy (cumulative incidence: 2.9%, 95% confidence interval [CI]: 2.3% to 3.6% for discontinuation versus 3.4%, 95% CI: 2.8% to 4.2% for continuation; HR = 0.84, 95% CI: 0.61 to 1.16, p = 0.298). Overall, 202 women who discontinued antidepressants during pregnancy and 156 who continued had psychiatric emergencies (cumulative incidence: 5.0%, 95% CI: 4.2% to 5.9% versus 3.7%, 95% CI: 3.1% to 4.5%). Antidepressant discontinuation during pregnancy was associated with increased risk of psychiatric emergency (HR = 1.25, 95% CI: 1.00 to 1.55, p = 0.048). Study limitations include lack of information on indications for antidepressant treatment and reasons for discontinuing antidepressants.

CONCLUSIONS

In this study, we found that discontinuing antidepressant medication during pregnancy (but not before) is associated with an apparent increased risk of psychiatric emergency compared to continuing treatment throughout pregnancy.

A surrogate measure for patient reported symptom remission in administrative data

BACKGROUND

In real-world pragmatic administrative databases, patient reported remission is often missing.

OBJECTIVE

We evaluate if, in administrative data, five features of antidepressant use patterns can replace patient-reported symptom remission.

METHOD

We re-examined data from Sequence Treatment Alternatives to Relieve Depression (STAR*D) study. Remission was measured using 50% reduction in Hamilton index. Pattern of antidepressant use was examined through five variables: (a) number of prior ineffective antidepressants, (b) duration of taking current antidepressant, (c) receiving therapeutic dose of the medication, and (d) switching to another medication, or (e) augmenting with another antidepressant. The likelihood ratio (LR) associated with each of these predictors was assessed in 90% of data (3329 cases) and evaluated in 10% of data (350 cases) set-aside for evaluation. The accuracy of predictions was calculated using Area under the Receiver Operating Curve (AROC).

RESULTS

Patients who took antidepressants for 14 weeks (LR = 2.007) were more likely to have symptom remission. Prior use of 3 antidepressants reduced the odds of remission (LR = 0.771). Patients who received antidepressants below therapeutic dose were 5 times less likely to experience remission (LR = 0.204). Antidepressant that were augment or switched, almost never led to remission (LR = 0.008, LR = 0.002 respectively). Patterns of antidepressant use accurately (AROC = 0.93) predicted symptom remission.

CONCLUSION

Within the first 100 days, antidepressants use patterns could serve as a surrogate measure for patient-reported remission of symptoms.

Association between Antidepressant Treatment during Pregnancy and Postpartum Self-Harm Ideation in Women with Psychiatric Disorders: A Cross-Sectional, Multinational Study

This study sought to estimate whether there is a preventative association between antidepressants during pregnancy and postpartum self-harm ideation (SHI), as this knowledge is to date unknown. Using the Multinational Medication Use in Pregnancy Study, we included a sample of mothers who were in the five weeks to one year postpartum period at the time of questionnaire completion, and reported preexisting or new onset depression and/or anxiety during pregnancy (n = 187). Frequency of postpartum SHI ('often/sometimes' = frequent, 'hardly ever' = sporadic, 'never') was measured via the Edinburgh Postnatal Depression Scale (EPDS) item 10, which reads "The thought of harming myself has occurred to me". Mothers reported their antidepressant use in pregnancy retrospectively. Overall, 52.9% of women took an antidepressant during pregnancy. Frequent SHI postpartum was reported by 15.2% of non-medicated women and 22.0% of women on past antidepressant treatment in pregnancy; this proportion was higher following a single trimester treatment compared to three trimesters (36.3% versus 18.0%). There was no preventative association of antidepressant treatment in pregnancy on reporting frequent SHI postpartum (weighted RR: 1.90, 95% CI: 0.79, 4.56), relative to never/hardly ever SHI. In a population of women with antenatal depression/anxiety, there was no preventative association between past antidepressant treatment in pregnancy and reporting frequent SHI in the postpartum year. This analysis is only a first step in providing evidence to inform psychiatric disorder treatment decisions for pregnant women.

Emulating a target trial of statin use and risk of dementia using cohort data

OBJECTIVE

Observational data can be used to attempt to emulate a target trial of statin use and estimate analogues of intention-to-treat and per protocol effects on dementia risk.

METHODS

Using data from a prospective cohort study in the Netherlands, we conceptualized a sequence of "trials" in which eligible individuals ages 55-80 years were classified as statin initiators or noninitiators for every consecutive month between 1993 and 2007 and were followed until diagnosis of dementia, death, loss to follow-up, or the end of follow-up. We estimated 2 types of effects of statin use on dementia and a combined endpoint of dementia or death: the effect of initiation vs no initiation and the effect of sustained use vs no use. We estimated risk by statin treatment strategy over time via pooled logistic regression. We used inverse-probability weighting to account for treatment-confounder feedback in estimation of per-protocol effects.

RESULTS

Of 233,526 eligible person-trials (6,373 individuals), there were 622 initiators and 232,904 noninitiators. Comparing statin initiation with no initiation, the 10-year risk differences (95% confidence interval) were -0.1% (-2.3% to 1.8%) for dementia and 0.3% (-2.7% to 3.3%) for dementia or death. Comparing sustained statin use vs no use, the 10-year risk differences were -2.2% (-5.2% to 1.6%) for dementia and -5.1% (-10.5% to -1.1%) for dementia or death.

CONCLUSIONS

Individuals with sustained statin use, but not statin initiation alone, had reduced 10-year risks of dementia and dementia or death. Our results should be interpreted with caution due to the small number of initiators and events and potential for residual confounding.

Schizophrenia around the time of pregnancy: leveraging population-based health data and electronic health record data to fill knowledge gaps

BACKGROUND

Research in schizophrenia and pregnancy has traditionally been conducted in small samples. More recently, secondary analysis of routine healthcare data has facilitated access to data on large numbers of women with schizophrenia.

AIMS

To discuss four scientific advances using data from Canada, Denmark and the UK from population-level health registers and clinical data sources.

METHOD

Narrative review of research from these three countries to illustrate key advances in the area of schizophrenia and pregnancy.

RESULTS

Health administrative and clinical data from electronic medical records have been used to identify population-level and clinical cohorts of women with schizophrenia, and follow them longitudinally along with their children. These data have demonstrated that fertility rates in women with schizophrenia have increased over time and have enabled documentation of the course of illness in relation with pregnancy, showing the early postpartum as the time of highest risk. As a result of large sample sizes, we have been able to understand the prevalence of and risk factors for rare outcomes that would be difficult to study in clinical research. Advanced pharmaco-epidemiological methods have been used to address confounding in studies of antipsychotic medications in pregnancy, to provide data about the benefits and risks of treatment for women and their care providers.

CONCLUSIONS

Use of these data has advanced the field of research in schizophrenia and pregnancy. Future developments in use of electronic health records include access to richer data sources and use of modern technical advances such as machine learning and supporting team science.

Factors associated with re-initiation of antidepressant treatment following discontinuation during pregnancy: a register-based cohort study

Antidepressant treatment when facing a pregnancy is an important issue for many women and their physicians. We hypothesized that women with a greater burden of pre-pregnancy psychiatric illness would be more likely to re-initiate antidepressants following discontinuation of treatment during pregnancy. A register-based cohort study was carried out including 38,595 women who gave birth between the 1st of January 2007 and the 31st of December 2014, who had filled a prescription for an antidepressant medication in the year prior to conception. Logistic regressions were used to explore associations between maternal characteristics and antidepressant treatment discontinuation or re-initiation during pregnancy. Most women discontinued antidepressant treatment during pregnancy (n = 29,095, 75.4%), of whom nearly 12% (n = 3434, 11.8%) re-initiated treatment during pregnancy. In adjusted analyses, parous women (aOR 1.22, 95% CI 1.12-1.33), with high educational level (aOR 1.21, 95% CI 1.08-1.36); born within the EU (excluding Nordic countries, aOR 1.41, 95% CI 1.03-1.92) or a Nordic country (aOR 1.42, 95% CI 1.22-1.65); who more often reported prior hospitalizations due to psychiatric disorders (aOR 1.50, 95% CI 1.10-2.03, for three or more episodes); and had longer duration of pre-pregnancy antidepressant use (aOR 6.10, 95% CI 5.48-6.77, for >2 years antidepressant use), were more likely to re-initiate antidepressants than were women who remained off treatment. Women with a greater burden of pre-pregnancy psychiatric illness were more likely to re-initiate antidepressants. Thus, pre-pregnancy psychiatric history may be particularly important for weighing the risks and benefits of discontinuing antidepressants during pregnancy.

Impact of antidepressant use, discontinuation, and dosage modification on maternal depression during pregnancy

Women tend to discontinue their antidepressants during pregnancy. This study compared the risk of depressive symptoms in the second-half of pregnancy in women who discontinue or continue with or without dosage modification their antidepressant during gestation. Women were eligible if they called MothertoBaby during 2006-2010 and within 14 completed weeks of pregnancy. A total of 367 pregnant women were included. The Edinburgh Postnatal Depression Scale (EPDS) was used to measure depression during the first and second half of pregnancy. Presence of depressive symptoms was defined as EPDS ≥13. Among participants, 149 did not use antidepressants, 38 used antidepressants at the beginning of pregnancy but discontinued before the end of second-trimester, and 180 used antidepressants continuously throughout pregnancy. Among continued users, 46 modified antidepressant dosage before the end of the second trimester, and 134 did not modify dosage. The majority of antidepressant users (150/218, 68.8%) had mild to moderate depression. Thirteen percent (13%) of women who continued antidepressant use throughout pregnancy without dosage modification remained depressed. Adjusting for potential confounders including maternal depression/anxiety before pregnancy, and compared to non-users, discontinued users were 5.95 times (95%CI: 1.54-23.02), and continued users without dosage modification 4.59 times (95%CI: 1.44-14.64) more at risk of depression in the second-half of pregnancy. Those with dosage modifications were at a similar risk of depression during pregnancy than non-users (adjusted odds ratio 0.58, 95%CI: 0.06-5.52). In conclusion, in a cohort of mild to moderate depressive pregnant women, discontinuing or continuing antidepressant use without dosage modification during pregnancy were associated with an increased risk of depression during the remaining gestational period.

Use of real-world evidence from healthcare utilization data to evaluate drug safety during pregnancy

PURPOSE

Because preapproval clinical trials typically exclude pregnant women, the evidence on drug safety during pregnancy required to inform drug labeling must come from postapproval controlled observational studies. Common designs have included pregnancy registries and case-control studies. Recently, pregnancy cohorts nested within healthcare utilization databases are increasingly being used. Despite clear advantages, these databases share some important limitations that may threaten the validity of studies emerging from them.

METHODS

This paper describes the distinctive methodological aspects of conducting drug safety studies in healthcare utilization databases with special emphasis on design and analytic approaches to minimize biases.

RESULTS

We describe considerations for study design, cohort definition, and follow-up. We then address issues related to exposure ascertainment based on prescription fills, including the importance of the etiologically relevant window and of properly accounting for preterm births. This is followed by a discussion of advantages and challenges when ascertaining maternal and infant outcomes based on secondary data. We then explore useful approaches to address confounding within the context of pregnancy research and of the potential for selection bias when restricting the cohort to live births. Finally, we consider issues related to external validity and statistical significance. The examples are mainly drawn from a pregnancy cohort nested in the Medicaid Analytic Extract.

CONCLUSIONS

The approaches presented provide guidance regarding the important methodological considerations that need to be attended to in order to generate valid, minimally biased risk when using large healthcare utilization databases for drug safety surveillance in pregnancy.

Bias in pharmacoepidemiologic studies using secondary health care databases: a scoping review

BACKGROUND

The availability of clinical and therapeutic data drawn from medical records and administrative databases has entailed new opportunities for clinical and epidemiologic research. However, these databases present inherent limitations which may render them prone to new biases. We aimed to conduct a structured review of biases specific to observational clinical studies based on secondary databases, and to propose strategies for the mitigation of those biases.

METHODS

Scoping review of the scientific literature published during the period 2000-2018 through an automated search of MEDLINE, EMBASE and Web of Science, supplemented with manually cross-checking of reference lists. We included opinion essays, methodological reviews, analyses or simulation studies, as well as letters to the editor or retractions, the principal objective of which was to highlight the existence of some type of bias in pharmacoepidemiologic studies using secondary databases.

RESULTS

A total of 117 articles were included. An increasing trend in the number of publications concerning the potential limitations of secondary databases was observed over time and across medical research disciplines. Confounding was the most reported category of bias (63.2% of articles), followed by selection and measurement biases (47.0% and 46.2% respectively). Confounding by indication (32.5%), unmeasured/residual confounding (28.2%), outcome misclassification (28.2%) and "immortal time" bias (25.6%) were the subcategories most frequently mentioned.

CONCLUSIONS

Suboptimal use of secondary databases in pharmacoepidemiologic studies has introduced biases in the studies, which may have led to erroneous conclusions. Methods to mitigate biases are available and must be considered in the design, analysis and interpretation phases of studies using these data sources.

Recurrence of depression in the perinatal period: Clinical features and associated vulnerability markers in an observational cohort

Objective

Antidepressant medication is commonly used for the prevention of depression recurrence in the perinatal period, yet it is unknown what vulnerability markers may play a role in recurrence. The objective of the current study was to provide a descriptive overview of the associated characteristics of women who experienced a perinatal recurrence of depression despite ongoing antidepressant use, and further, to identify clinically measurable vulnerability markers associated with recurrence.

Methods

Eighty-five pregnant women with a history of depression who used antidepressants (e.g. Selective Serotonin Reuptake Inhibitors or Serotonin and Noradrenaline Reuptake Inhibitors) at the start of the study were included. Clinical features, including information on psychiatric history and antidepressant use, were collected throughout the perinatal period (in this study defined as the period between 12 weeks of pregnancy untill three months postpartum). The clinical features of women experiencing recurrence of depression were described in detail. To identify vulnerability markers associated with recurrence of depression, we performed exploratory univariable logistic regression analyses.

Results

Eight women (9.4%) experienced a recurrence of depression; two during pregnancy and six in the first 12 weeks postpartum. All women with recurrence of depression had first onset of depression during childhood or adolescence and had at least 2 psychiatric co-morbidities. Identification of vulnerability markers associated with recurrence of depression yielded associations with depressive symptoms around 16 weeks of pregnancy (OR 1.28, 95%CI 1.08–1.52), number of psychiatric co-morbidities (OR 1.89, 95%CI 1.16–3.09) and duration of antidepressant use (OR 1.01, 95%CI 1.00–1.02).

Conclusion

Implementing adequate risk assessment in pregnant women who use antidepressants can help identify predictors for recurrence of depression in future studies and thus ultimately lead to improved care.

Methods for the assessment of selection bias in drug safety during pregnancy studies using electronic medical data

Electronic health data are routinely used for population drug studies. Due to the ethical dilemma in carrying out experimental drug studies on pregnant women, the effects of medication usage during pregnancy on fetal and maternal outcomes are largely evaluated using this data collection medium. One major limitation in this type of study is the delayed inclusion of pregnancies in the cohort. For example, in the province of Quebec, Canada, a major pregnancy cohort only captured pregnancies after 20 weeks gestation. The purpose of this study was to demonstrate three methods that can be used to assess the extent of selection bias due to the delayed inclusion of pregnancies. We use causal directed acyclic graphs to explain the source of this selection bias. In an example involving a cohort of pregnant asthmatic women reconstructed from the linkage of administrative health databases from the province of Quebec, we use numerical derivations, a simulation study and a sensitivity analysis to investigate the potential for bias and loss of power due to the delayed inclusion. We find that this selection bias can be partially mitigated by controlling for variables related to (spontaneous or therapeutic) abortion and the outcome of interest. The three proposed methods allow for the pre and post hoc ascertainment of the bias. While delayed pregnancy inclusion selection bias (which includes "live birth bias") can produce substantial bias in pregnancy drug studies, all three methods are effective at producing estimates of the size of the bias.

Predictors of severe relapse in pregnant women with psychotic or bipolar disorders

Pregnancy in women with severe mental illness is associated with adverse outcomes for mother and infant. There are limited data on prevalence and predictors of relapse in pregnancy. A historical cohort study using anonymised comprehensive electronic health records from secondary mental health care linked with national maternity data was carried out. Women with a history of serious mental illness who were pregnant (2007-2011), and in remission at the start of pregnancy, were studied; severe relapse was defined as admission to acute care or self-harm. Predictors of relapse were analysed using random effects logistic regression to account for repeated measures in women with more than one pregnancy in the study period. In 454 pregnancies (389 women) there were 58 (24%) relapses in women with non-affective psychoses and 25 (12%) in women with affective psychotic or bipolar disorders. Independent predictors of relapse included non-affective psychosis (adjusted OR = 2.03; 95% CI = 1.16-3.54), number of recent admissions (1.37; 1.03-1.84), recent self-harm (2.24; 1.15-4.34), substance use (2.15; 1.13-4.08), smoking (2.52; 1.26-5.02) and non-white ethnicity (black ethnicity: 2.37; 1.23-4.57, mixed/other ethnicity: 2.94; 1.32-6.56). Women on no regular medication throughout first trimester were also at greater risk of relapse in pregnancy (1.99; 1.05-3.75). There was no interaction between severity of illness and medication status as relapse predictors. Therefore, women with non-affective psychosis and higher number of recent acute admissions are at significant risk of severe relapse in pregnancy. Continuation of medication in women with severe mental illness who become pregnant may be protective.

Self-reported perinatal depressive symptoms and postnatal symptom severity after treatment with antidepressants in pregnancy: a cross-sectional study across 12 European countries using the Edinburgh Postnatal Depression Scale

PURPOSE

This study aimed at exploring the prevalence of self-reported antenatal and postnatal depressive symptoms by severity across multiple countries and the association between antidepressant treatment in pregnancy and postnatal symptom severity.

MATERIALS AND METHODS

This was a multinational web-based study conducted across 12 European countries (n=8069). Uniform data collection was ensured via an electronic questionnaire. Pregnant women at any gestational week and mothers of children with <1 year of age could participate. We used the Edinburgh Postnatal Depression Scale (EPDS) to measure the prevalence of antenatal and postnatal depressive symptoms according to severity, which were corrected by survey weight adjustment (descriptive analysis). Within mothers with a psychiatric disorder (n=173), we estimated the association between antidepressant treatment in pregnancy and postnatal depressive symptom severity, as standardized EPDS mean scores, via the inverse probability of treatment weight (association analysis).

RESULTS

In the descriptive analysis (n=8069), the period prevalence of moderate-to-very severe depressive symptoms was higher in the western and eastern regions relative to the northern region, both in the antenatal period (6.8%-7.5% vs 4.3%) and in the postnatal period (7.6% vs 4.7%). One in two mothers with psychiatric disorders used an antidepressant in pregnancy (86 of 173). In the association analysis, women medicated at any time during pregnancy (adjusted β=-0.34, 95% confidence interval [CI] =-0.66, -0.02) had a significant postnatal symptom severity reduction compared with the nonmedicated counterpart. This effect was larger (β=-0.74, 95% CI =-1.24, -0.24) when the analysis was restricted to mothers within 6 months after childbirth.

CONCLUSION

The prevalence of self-reported antenatal and postnatal depressive symptoms differs across European countries. Among women with psychiatric disorders, those who had been on treatment with antidepressants during pregnancy were less likely to report postnatal depressive symptoms, particularly within the 6-month period after childbirth, compared with the nonmedicated counterpart.

Patterns of antidepressant use during pregnancy: a nationwide population-based cohort study

AIMS

We explored the patterns of antidepressant use during pregnancy.

METHODS

A cohort of women who started a pregnancy in 2014 was identified using data from the French reimbursement healthcare system (covering approximately 99% of the population). Antidepressant usage (initiated before or during pregnancy) was assessed. Explored changes in antidepressant treatment were: associations, switches, discontinuation and resumption of antidepressants during pregnancy.

RESULTS

The cohort included 766 508 pregnancies (755 519 women). Antidepressant use during pregnancy was 25.7 per 1000 [95% CI: 25.3-26.0]. New use concerned 3.9 per 1000 [95% CI: 3.7-4.0]; the most initiated class during pregnancy was selective serotonin reuptake inhibitors (SSRIs), while the most prescribed individual drug in second and third trimesters was amitriptyline, a tricyclic. Most changes were observed before pregnancy and during the first trimester: 63% of ongoing treatments in the year before pregnancy were discontinued before conception; 68% of treatments maintained after conception were discontinued during the first trimester; switches or antidepressant associations mostly occurred during the periconceptional period or during the first trimester. Regardless of initial antidepressant, switches to sertraline were the most frequent. Associations mainly consisted of a prescription of tri-/tetracyclic or mirtazapine/mianserin in addition to an SSRI. Discontinuation during pregnancy led to treatment resumption in 22% of pregnancies.

CONCLUSIONS

These results suggest that pregnancy was planned or the treatment especially adapted in accordance with existing recommendations in a large proportion of women under antidepressants or in whom such treatments have been initiated after starting a pregnancy.

Mental health follow-up after deliberate self-harm and risk for repeat self-harm and death

Morbidity and mortality after deliberate self-harm (DSH) are high, so mental health care shortly after DSH is recommended. Using population-level health data we determined the association between a mental health visit and risk for repeat DSH with or without intensive care unit (ICU) admission or all-cause death. Over two years, 23,140 individuals had emergency department treatment for DSH. Within 30 days, 10.7% had a family physician mental health visit, 17.1% visited a psychiatrist, 3.6% visited both and 68.6% neither. Individuals who received mental health follow-up had more chronic and severe mental illness and higher acuity DSH. Over five years, repeat DSH occurred in 4792 (20.7%). Repeat DSH was more common in those who had a mental health visit within 30 days. Adjusting for baseline characteristics attenuated these differences. Similar results were found for DSH with ICU admission (5.0%) and death (7.6%). More frequent follow-up was not associated with better outcome. Timely access to mental health care after DSH was poor at 31%. Follow-up care had virtually no association with subsequent risk, so treatment as usual is insufficient. Post-DSH care augmented with evidence-based interventions is required.

Instrumental Variable Analyses in Pharmacoepidemiology: What Target Trials Do We Emulate?

Purpose of review

When leveraging observational data to estimate treatment effects, it is useful to explicitly specify the “target trial” the investigators aspire to emulate. One concern is whether a proposed analysis plan can address the realities of the differences between the available non-randomized observational study and the target trial. When large or unknown sources of unmeasured confounding are suspected, investigators might consider turning to instrumental variable (IV) methods. Of course, the interpretation and appropriateness of IV analyses need to be considered carefully. The purpose of this review is to summarize recent methodologic advancements in how epidemiologists weigh the validity of an IV analysis and to place these methodologic advancements in the context of the feasible target trial’s protocol components.

Recent findings

There have been increased development and application of tools for sensitivity analyses, falsification strategies, and the identification of previously overlooked problems with IV analyses as applied in pharmacoepidemiology. Many of these recent insights can be seen as articulating restrictions on or tradeoffs between the types of target trials that can be validly emulated when using a classical IV analysis.

Summary

Putting classical IV methods in the context of target trials underscores the importance of recent methodologic developments and, more generally, when and how an IV analysis would be appropriate. We see that some tradeoffs in defining the target trials are unavoidable, that some tradeoffs may be offset or explored via sensitivity analyses, and that this serves as a framework for scientific discourse regarding IV and non-IV results emulating potentially different trials with different tradeoffs.

Making fair comparisons in pregnancy medication safety studies: An overview of advanced methods for confounding control

Understanding the safety of medication use during pregnancy relies on observational studies: However, confounding in observational studies poses a threat to the validity of estimates obtained from observational data. Newer methods, such as marginal structural models and propensity calibration, have emerged to deal with complex confounding problems, but these methods have seen limited uptake in the pregnancy medication literature. In this article, we provide an overview of newer advanced methods for confounding control and show how these methods are relevant for pregnancy medication safety studies.

Psychotropic Drug Use before, during, and after Pregnancy: A Population-Based Study in a Canadian Cohort (2001-2013)

OBJECTIVE

To describe the extent of increase in use and the rate of continuation versus discontinuation of psychotropic agents before, during, and after pregnancy.

METHODS

Rates of psychotropic use (antidepressants, anxiolytic/sedative-hypnotics, antiepileptics, antipsychotics, lithium, stimulants) among women with a hospital-recorded pregnancy outcome were assessed using databases at the Manitoba Centre for Health Policy. Rate of use was defined as ≥1 prescription over the total number of pregnancies in the 3-12 months before pregnancy, 0-3 months before pregnancy, during pregnancy, or 3 months after pregnancy. Continued use was defined as ≥2 prescriptions with gap ≤14 days. Poisson regression was used to analyze trends.

RESULTS

Over the study period, a psychotropic drug was used before, during, or after pregnancy in 41,923 of 224,762 pregnancies. From 2001 to 2013, psychotropic use increased 1.5-fold from 11.1% to 16.2% ( p < 0.0001) in the 3-12 months before pregnancy, 1.6-fold from 6.4% to 10.5% ( p < 0.0001) in the 3 months before pregnancy, 1.8-fold from 3.3% to 6.0% ( p < 0.0001) during pregnancy, and 1.5-fold from 6.2% to 9.5% ( p < 0.0001) in the 3 months postpartum. Among the 13,579 women who received at least 1 psychotropic agent in the 3 months prior to pregnancy, 38.5% stopped the agent prior to pregnancy and only 10.3% continued use throughout pregnancy. Continued use throughout pregnancy was higher (56.9%) among the 6693 women who received at least 2 prescriptions for a psychotropic agent and were at least 80% adherent in the 3 months prior to pregnancy.

CONCLUSION

The use of psychotropic agents increased over 12 years. The safety of continuing versus discontinuing these agents during pregnancy remains uncertain, but we observed a decrease in psychotropic drug use during the pregnancy period.

Association between CYP2D6 Genotypes and the Risk of Antidepressant Discontinuation, Dosage Modification and the Occurrence of Maternal Depression during Pregnancy

Importance: Polymorphic expression of drug metabolizing enzymes affects the metabolism of antidepressants, and thus can contribute to drug response and/or adverse events. Pregnancy itself can affect CYP2D6 activity with profound variations determined by CYP2D6 genotype. Objective: To investigate the association between CYP2D6 genotype and the risk of antidepressant discontinuation, dosage modification, and the occurrence of maternal CYP2D6, Antidepressants, Depression during pregnancy. Setting: Data from the Organization of Teratology Information Specialists (OTIS) Antidepressants in Pregnancy Cohort, 2006-2010, were used. Women were eligible if they were within 14 completed weeks of pregnancy at recruitment and exposed to an antidepressant or having any exposures considered non-teratogenic. Main Outcomes and Measures: Gestational antidepressant usage was self-reported and defined as continuous/discontinued use, and non-use; dosage modification was further documented. Maternal depression and anxiety were measured every trimester using the telephone interviewer-administered Edinburgh Postnatal Depression Scale and the Beck Anxiety Inventory, respectively. Saliva samples were collected and used for CYP2D6 genotype analyses. Logistic regression models were used to calculate crude and adjusted odds ratios (OR) with 95% confidence intervals. Results: A total of 246 pregnant women were included in the study. The majority were normal metabolizers (NM, n = 204, 83%); 3.3% (n = 8) were ultrarapid metabolizers (UM), 5.7% (n = 14) poor metabolizers (PM), and 8.1% (n = 20) intermediate metabolizers (IM). Among study subjects, 139 women were treated with antidepressants at the beginning of pregnancy, and 21 antidepressant users (15%) discontinued therapy during pregnancy. Adjusting for depressive symptoms, and other potential confounders, the risk of discontinuing antidepressants during pregnancy was nearly four times higher in slow metabolizers (poor or intermediate metabolizers) compared to those with a faster metabolism rate (normal or ultrarapid metabolizers), aOR = 3.57 (95% CI: 1.15-11.11). Predicted CYP2D6 metabolizer status did not impact dosage modifications. Compared with slow metabolizers, significantly higher proportion of women in the fast metabolizer group had depressive symptom in the first trimester (19.81 vs. 5.88%, P = 0.049). Almost 21% of treated women remained depressed during pregnancy (14.4% NM-UM; 6.1% PM-IM). Conclusions and Relevance: Prior knowledge of CYP2D6 genotype may help to identify pregnant women at greater risk of antidepressant discontinuation. Twenty percent of women exposed to antidepressants during pregnancy remained depressed, indicating an urgent need for personalized treatment of depression during pregnancy.

The impact of exposure to antidepressant medications during pregnancy on neonatal outcomes: a review of retrospective database cohort studies

INTRODUCTION

Concerns with prescription antidepressant use in pregnant women have instigated the examination of potential associations between fetal exposure to antidepressant medication and outcomes including preterm delivery, congenital malformations, perinatal and post-natal adverse events, persistent pulmonary hypertension, and mortality. The retrospective cohort model is an often utilized study design. The objective of this review is to evaluate the literature on antidepressant use in pregnancy conducted as retrospective cohorts in national/regional medical, or claims databases that assess neonatal and infant outcomes for agreement between studies, ultimately providing a methodological and outcomes summary for future scientific endeavors.

METHODS

PubMed was searched for literature relating to antidepressant use and infant outcomes from the earliest available date through July 15, 2016. Studies with a retrospective cohort design and conducted in national/regional medical or claims databases were included. Searched outcomes included preterm delivery, congenital malformations, low birth weight, small for gestational age, persistent pulmonary hypertension of the newborn, and other select adverse events comprising low Apgar score (5 min), convulsions/seizures, respiratory distress/problems, fetal mortality, and infant mortality.

RESULTS

Of the 784 studies identified, 36 retrospective cohort studies met eligibility criteria. An increase in preterm delivery and respiratory distress/problems and no increase in congenital malformation or fetal and infant death were associated with prenatal use of prescription antidepressants by majority consensus (at least 2/3 [67%] of studies).

CONCLUSIONS

While consensus indicates that perinatal prescription antidepressant use has consequences for the fetus and infant, there are notable inconsistencies in the literature. More investigations that address prenatal exposure to depression and other important covariates are needed.

Antidepressant use during pregnancy and the risk of major congenital malformations in a cohort of depressed pregnant women: an updated analysis of the Quebec Pregnancy Cohort

OBJECTIVE

Antidepressant use during gestation has been associated with risk of major congenital malformations but estimates can lack statistical power or be confounded by maternal depression. We aimed to determine the association between first-trimester exposure to antidepressants and the risk of major congenital malformations in a cohort of depressed/anxious women.

SETTING AND PARTICIPANTS

Data were obtained from the Quebec Pregnancy Cohort (QPC). All pregnancies with a diagnosis of depression or anxiety, or exposed to antidepressants in the 12 months before pregnancy, and ending with a live-born singleton were included.

OUTCOME MEASURES

Antidepressant classes (selective serotonin reuptake inhibitors (SSRI), serotonin-norepinephrine reuptake inhibitors (SNRI), tricyclic antidepressants (TCA) and other antidepressants) and types were individually compared with non-exposure during the first trimester (depressed untreated). Major congenital malformations overall and organ-specific malformations in the first year of life were identified.

RESULTS

18 487 pregnant women were included. When looking at the specific types of antidepressant used during the first trimester, only citalopram was increasing the risk of major congenital malformations (adjusted OR, (aOR) 1.36, 95% CI 1.08 to 1.73; 88 exposed cases), although there was a trend towards increased risk for the most frequently used antidepressants. Antidepressants with serotonin reuptake inhibition effect (SSRI, SNRI, amitriptyline (the most used TCA)) increased the risk of certain organ-specific defects: paroxetine increased the risk of cardiac defects (aOR 1.45, 95% CI 1.12 to 1.88), and ventricular/atrial septal defects (aOR 1.39, 95% CI 1.00 to 1.93); citalopram increased the risk of musculoskeletal defects (aOR 1.92, 95% CI 1.40 to 2.62), and craniosynostosis (aOR 3.95, 95% CI 2.08 to 7.52); TCA was associated with eye, ear, face and neck defects (aOR 2.45, 95% CI 1.05 to 5.72), and digestive defects (aOR 2.55, 95% CI 1.40 to 4.66); and venlafaxine was associated with respiratory defects (aOR 2.17, 95% CI 1.07 to 4.38).

CONCLUSIONS

Antidepressants with effects on serotonin reuptake during embryogenesis increased the risk of some organ-specific malformations in a cohort of pregnant women with depression.