Association between mirtazapine use and serious self-harm in people with depression: an active comparator cohort study using UK electronic health records.

BACKGROUND: Studies report an increased risk of self-harm or suicide in people prescribed mirtazapine compared with other antidepressants. OBJECTIVES: To compare the risk of serious self-harm in people prescribed mirtazapine versus other antidepressants as second-line treatments. DESIGN AND SETTING: Cohort study using anonymised English primary care electronic health records, hospital admission data and mortality data with study window 1 January 2005 to 30 November 2018. PARTICIPANTS: 24 516 people diagnosed with depression, aged 18-99 years, initially prescribed a selective serotonin reuptake inhibitor (SSRI) and then prescribed mirtazapine, a different SSRI, amitriptyline or venlafaxine. MAIN OUTCOME MEASURES: Hospitalisation or death due to deliberate self-harm. Age-sex standardised rates were calculated and survival analyses were performed using inverse probability of treatment weighting to account for baseline covariates. RESULTS: Standardised rates of serious self-harm ranged from 3.8/1000 person-years (amitriptyline) to 14.1/1000 person-years (mirtazapine). After weighting, the risk of serious self-harm did not differ significantly between the mirtazapine group and the SSRI or venlafaxine groups (HRs (95% CI) 1.18 (0.84 to 1.65) and 0.85 (0.51 to 1.41) respectively). The risk was significantly higher in the mirtazapine than the amitriptyline group (3.04 (1.36 to 6.79)) but was attenuated after adjusting for dose. CONCLUSIONS: There was no evidence for a difference in risk between mirtazapine and SSRIs or venlafaxine after accounting for baseline characteristics. The higher risk in the mirtazapine versus the amitriptyline group might reflect residual confounding if amitriptyline is avoided in people considered at risk of self-harm. CLINICAL IMPLICATIONS: Addressing baseline risk factors and careful monitoring might improve outcomes for people at risk of serious self-harm.

The risk of all-cause and cause-specific mortality in people prescribed mirtazapine: an active comparator cohort study using electronic health records.

BACKGROUND: Studies have reported an increased risk of mortality among people prescribed mirtazapine compared to other antidepressants. The study aimed to compare all-cause and cause-specific mortality between adults prescribed mirtazapine or other second-line antidepressants. METHODS: This cohort study used English primary care electronic medical records, hospital admission records, and mortality data from the Clinical Practice Research Datalink (CPRD), for the period 01 January 2005 to 30 November 2018. It included people aged 18-99 years with depression first prescribed a selective serotonin reuptake inhibitor (SSRI) and then prescribed mirtazapine (5081), a different SSRI (15,032), amitriptyline (3905), or venlafaxine (1580). Follow-up was from starting to stopping the second antidepressant, with a 6-month wash-out window, censoring at the end of CPRD follow-up or 30 November 2018. Age-sex standardised rates of all-cause mortality and death due to circulatory system disease, cancer, or respiratory system disease were calculated. Survival analyses were performed, accounting for baseline characteristics using inverse probability of treatment weighting. RESULTS: The cohort contained 25,598 people (median age 41 years). The mirtazapine group had the highest standardised mortality rate, with an additional 7.8 (95% confidence interval (CI) 5.9-9.7) deaths/1000 person-years compared to the SSRI group. Within 2 years of follow-up, the risk of all-cause mortality was statistically significantly higher in the mirtazapine group than in the SSRI group (weighted hazard ratio (HR) 1.62, 95% CI 1.28-2.06). No significant difference was found between the mirtazapine group and the amitriptyline (HR 1.18, 95% CI 0.85-1.63) or venlafaxine (HR 1.11, 95% CI 0.60-2.05) groups. After 2 years, the risk was significantly higher in the mirtazapine group compared to the SSRI (HR 1.51, 95% CI 1.04-2.19), amitriptyline (HR 2.59, 95% CI 1.38-4.86), and venlafaxine (HR 2.35, 95% CI 1.02-5.44) groups. The risks of death due to cancer (HR 1.74, 95% CI 1.06-2.85) and respiratory system disease (HR 1.72, 95% CI 1.07-2.77) were significantly higher in the mirtazapine than in the SSRI group. CONCLUSIONS: Mortality was higher in people prescribed mirtazapine than people prescribed a second SSRI, possibly reflecting residual differences in other risk factors between the groups. Identifying these potential health risks when prescribing mirtazapine may help reduce the risk of mortality.

Association between opioid-related deaths and persistent opioid prescribing in primary care in England: A nested case-control study.

AIM: This study aimed to evaluate the association between opioid-related deaths and persistent opioid utilisation in the United Kingdom (UK). METHODS: This nested case-control study used the UK Clinical Practice Research Datalink, linking the Office for National Statistics death registration. Adult opioid users with recorded opioid-related death between 2000 and 2015 were included and matched to four opioid users (controls) based on a disease risk score. Persistent opioid utilisation (opioid prescriptions ≥3 quarters/year and oral morphine equivalent dose ≥4500 mg/year) and psychotropic prescriptions were identified annually during the three patient-years before the date of opioid-related death. Conditional logistic regression was used to assess the association between persistent opioid utilisation and opioid-related death, and the results were reported as adjusted odds ratios (aOR) and 95% confidence intervals (95% CI). RESULTS: Of the 902 149 opioid users, 230 opioid-related deaths (cases) and 920 controls were identified. Persistent opioid utilisation was significantly associated with an increased risk of opioid-related deaths (aOR 1.9, 95% CI 1.2, 2.9) when persistent opioid utilisation was defined by both annual dose and number of quarters. Concurrent prescription of opioids and tricyclic antidepressants (aOR 2.0, 95% CI 1.2, 3.5) or higher dose of benzodiazepine (aOR 6.5, 95% CI 4.0, 10.4) or gabapentinoids (aOR 6.2, 95% CI 2.9, 13.5) were associated with opioid-related death. CONCLUSION: Persistent opioid prescribing and concurrent prescribing of psychotropics were associated with a higher risk of opioid-related death and should be avoided in clinical practice. An evidence-based indicator to monitor the safety of prescribed opioids during opioid deprescribing is needed.

Current use of analgesics and the risk of falls in people with knee osteoarthritis: A population-based cohort study using primary care and hospital records.

Objective: To examine the association between the current use of analgesics and the risk of falls in people with knee osteoarthritis (KOA). Methods: A retrospective cohort study using data from the UK Clinical Practice Research Datalink, with linkage to Hospital Episode Statistics data. People diagnosed with KOA in England between 2000 and 2014 were included. The studied analgesic classes were antidepressants, antiepileptic drugs (AEDs), opioids, non-steroidal anti-inflammatory drugs (NSAIDs) and paracetamol. Cox Proportional Hazards model was used to estimate the risk of fall with current use of analgesics within one year of KOA diagnosis, reported as Hazard Ratio (HR) with 95% Confidence Intervals (CI). Results: This study included 57,383 patients (mean age [SD] 67.0 [12.8] years, 59.3% were female); 44,010 (76.7%) were prescribed analgesics at least once within one year of KOA diagnosis. Within the first six months of KOA diagnosis, the reported HR (95%CI) were 1.46 (1.20, 1.78), 1.40 (0.91, 2.16), 2.40 (2.01, 2.85), 1.72 (1.43, 2.07), 1.98 (1.68, 2.33), while between 6 and 12 months after KOA diagnosis, the HR (95%CI) were 2.68 (2.14, 3.36), 2.22 (1.70, 2.91), 1.96 (1.70, 2.26), 1.47 (1.21, 1.78), 1.92 (1.63, 2.26) for antidepressants, AEDs, opioids, NSAIDs and paracetamol, respectively and adjusted for important potential confounders. Conclusion: The current use of analgesics was associated with an increased risk of falls within one year of KOA diagnosis. These findings identify people with KOA who use analgesics as a priority for fall prevention programs/interventions, in an effort to optimise safety of analgesics in this population.

Incidence and prevalence of primary care antidepressant prescribing in children and young people in England, 1998-2017: A population-based cohort study.

BACKGROUND: The use of antidepressants in children and adolescents remains controversial. We examined trends over time and variation in antidepressant prescribing in children and young people in England and whether the drugs prescribed reflected UK licensing and guidelines. METHODS AND FINDINGS: QResearch is a primary care database containing anonymised healthcare records of over 32 million patients from more than 1,500 general practices across the UK. All eligible children and young people aged 5-17 years in 1998-2017 from QResearch were included. Incidence and prevalence rates of antidepressant prescriptions in each year were calculated overall, for 4 antidepressant classes (selective serotonin reuptake inhibitors [SSRIs], tricyclic and related antidepressants [TCAs], serotonin and norepinephrine reuptake inhibitors [SNRIs], and other antidepressants), and for individual drugs. Adjusted trends over time and differences by social deprivation, region, and ethnicity were examined using Poisson regression, taking clustering within general practitioner (GP) practices into account using multilevel modelling. Of the 4.3 million children and young people in the cohort, 49,434 (1.1%) were prescribed antidepressants for the first time during 20 million years of follow-up. Males made up 52.0% of the cohorts, but only 34.1% of those who were first prescribed an antidepressant in the study period. The largest proportion of the cohort was from London (24.4%), and whilst ethnicity information was missing for 39.5% of the cohort, of those with known ethnicity, 75.3% were White. Overall, SSRIs (62.6%) were the most commonly prescribed first antidepressant, followed by TCAs (35.7%). Incident antidepressant prescribing decreased in 5- to 11-year-olds from a peak of 0.9 in females and 1.6 in males in 1999 to less than 0.2 per 1,000 for both sexes in 2017, but incidence rates more than doubled in 12- to 17-year-olds between 2005 and 2017 to 9.7 (females) and 4.2 (males) per 1,000 person-years. The lowest prescription incidence rates were in London, and the highest were in the South East of England (excluding London) for all sex and age groups. Those living in more deprived areas were more likely to be prescribed antidepressants after adjusting for region. The strongest trend was seen in 12- to 17-year-old females (adjusted incidence rate ratio [aIRR] 1.12, 95% confidence interval [95% CI] 1.11-1.13, p < 0.001, per deprivation quintile increase). Prescribing rates were highest in White and lowest in Black adolescents (aIRR 0.32, 95% CI 0.29-0.36, p < 0.001 [females]; aIRR 0.32, 95% CI 0.27-0.38, p < 0.001 [males]). The 5 most commonly prescribed antidepressants were either licensed in the UK for use in children and young people (CYP) or included in national guidelines. Limitations of the study are that, because we did not have access to secondary care prescribing information, we may be underestimating the prevalence and misidentifying the first antidepressant prescription. We could not assess whether antidepressants were dispensed or taken. CONCLUSIONS: Our analysis provides evidence of a continuing rise of antidepressant prescribing in adolescents aged 12-17 years since 2005, driven by SSRI prescriptions, but a decrease in children aged 5-11 years. The variation in prescribing by deprivation, region, and ethnicity could represent inequities. Future research should examine whether prescribing trends and variation are due to true differences in need and risk factors, access to diagnosis or treatment, prescribing behaviour, or young people's help-seeking behaviour.

Secondary care specialist visits made by children and young people prescribed antidepressants in primary care: a descriptive study using the QResearch database.

BACKGROUND: Antidepressants may be used to manage a number of conditions in children and young people including depression, anxiety, and obsessive-compulsive disorder. UK guidelines for the treatment of depression in children and young people recommend that antidepressants should only be initiated following assessment and diagnosis by a child and adolescent psychiatrist. The aim of this study was to summarise visits to mental health specialists and indications recorded around the time of antidepressant initiation in children and young people in UK primary care. METHODS: The study used linked English primary care electronic health records and Hospital Episode Statistics secondary care data. The study included 5-17-year-olds first prescribed antidepressants between January 2006 and December 2017. Records of visits to paediatric or psychiatric specialists and potential indications (from a pre-specified list) were extracted. Events were counted if recorded less than 12 months before or 6 months after the first antidepressant prescription. Results were stratified by first antidepressant type (all, selective serotonin reuptake inhibitors (SSRIs), tricyclic and related antidepressants) and by age group (5-11 years, 12-17 years). RESULTS: In total, 33,031 5-17-year-olds were included. Of these, 12,149 (37%) had a record of visiting a paediatrician or a psychiatric specialist in the specified time window. The majority of recorded visits (7154, 22%) were to paediatricians. Of those prescribed SSRIs, 5463/22,130 (25%) had a record of visiting a child and adolescent psychiatrist. Overall, 17,972 (54%) patients had a record of at least one of the pre-specified indications. Depression was the most frequently recorded indication (12,501, 38%), followed by anxiety (4155, 13%). CONCLUSIONS: The results suggest many children and young people are being prescribed antidepressants without the recommended involvement of a relevant specialist. These findings may justify both greater training for GPs in child and adolescent mental health and greater access to specialist care and non-pharmacological treatments. Further research is needed to explore factors that influence how and why GPs prescribe antidepressants to children and young people and the real-world practice barriers to adherence to clinical guidelines.

Trends in antidepressant prescriptions in children and young people in England, 1998-2017: protocol of a cohort study using linked primary care and secondary care datasets.

INTRODUCTION: Increasing numbers of children and young people (CYP) are receiving prescriptions for antidepressants. This is the protocol of a study aiming to describe the trends and variation in antidepressant prescriptions in CYP in England, and to examine the indications for the prescriptions recorded and whether there was contact with secondary care specialists on or around the time of the first antidepressant prescription. METHODS AND ANALYSIS: All eligible CYP aged between 5 and 17 years in 1998-2017 from the QResearch primary care database will be included. Incidence and prevalence rates of any antidepressant prescription in each year will be calculated. We will examine four different antidepressant classes: selective serotonin reuptake inhibitors, tricyclic and related antidepressants, serotonin and norepinephrine reuptake inhibitors and other antidepressants, as well as for individual drugs. Linked primary and secondary care data (hospital episode statistics) in the year before and up to 6 months after the first antidepressant prescription will be examined for CYP whose first antidepressant prescription was in 2006-2017. Whether there were records of indications and being seen by psychiatric or paediatric specialists will be identified. Trends over time and differences by region, deprivation and ethnicity will be examined using Poisson regression. DISCUSSION: This large, population-based study will give an up-to-date picture of antidepressant prescribing in CYP and identify any variation. Understanding what indications are recorded when CYP are being prescribed antidepressants, and whether this was done in partnership with secondary care specialists, will provide evidence of whether appropriate guidelines are being followed.

Prescription opioids: Regional variation and socioeconomic status - evidence from primary care in England.

BACKGROUND: This study aimed to quantify opioid prescriptions dispensed from primary care practices throughout England and investigate its association with socioeconomic status (SES). METHODS: This cross-sectional study used publicly available data in 2015, including practice-level dispensing data and characteristics of registrants from the United Kingdom (UK) National Health Service Digital, and Index of Multiple Deprivation (IMD) data from Department of Communities and Local Government. Practices in England which issued opioid prescriptions that could be assigned a defined daily dose (DDD) in the claim-based dispensing database were included. The total amount of opioid prescriptions dispensed (DDD/1000 registrants/day) was calculated for each practice. The association between dispensed opioid prescriptions and IMD was analyzed by multi-level regression and adjusted for registrants' characteristics and the clustered effect of Clinical Commissioning Groups. Subgroup analysis was conducted for practices in London, Birmingham, Manchester and Newcastle. RESULTS: Of the 7856 included practices in England, the median and interquartile range (IQR) of prescription opioids dispensed was 36.9 (IQR: 23.1, 52.5) DDD/1000 registrants/day. The median opioid utilization (DDD/1000 registrants/day) amongst practices varied between Manchester (53.1; IQR: 36.8, 71.4), Newcastle (48.9; IQR: 38.8, 60.1), Birmingham (35.3; IQR: 23.1, 49.4) and London (13.9; IQR: 8.1, 18.8). Lower SES, increased prevalence of patients aged more than 65 years, female gender, smoking, obesity and depression were significantly associated with increased opioid prescriptions. For every decrease in IMD decile (lower SES), there was a significant increase of opioid utilization by 1.0 (95% confidence interval: 0.89, 1.2, P < 0.001) DDD/1000 registrants/day. CONCLUSION: There was substantial variation in opioid prescriptions among practices from Northern and Eastern England to Southern England. A significant association between increased opioid prescriptions and greater deprivation at a population level was observed. Further longitudinal studies using individual patient data are needed to validate this association and identify the potential mechanisms.

A 15-year overview of increasing tramadol utilisation and associated mortality and the impact of tramadol classification in the United Kingdom.

PURPOSE: This study aimed to develop hypotheses to explain the increasing tramadol utilisation, evaluate the impact of tramadol classification, and explore the trend between tramadol utilisation and related deaths in the United Kingdom. METHODS: This cross-sectional study used individual patient data, the Clinical Practice Research Datalink from 1993 to 2015, to calculate monthly defined daily dose (DDD)/1000 registrants, monthly prevalence and incidence of tramadol users, annual supply days, and mean daily dose of tramadol. Aggregated-level national statistics and reimbursement data from 2004 to 2015 were also used to quantify annual and monthly tramadol DDD/1000 inhabitants and rate of tramadol-related deaths in England and Wales. Interrupted time-series analysis was used to evaluate the impact of tramadol classification in June 2014. RESULTS: Prevalence of tramadol users increased from 23 to 97.6/10 000 registrants from 2000 to 2015. Both annual dose and annual supply days of existing tramadol users were higher than new users. Level and trend of monthly utilisation (ß2 : -12.9, ß3 : -1.6) and prevalence of tramadol users (ß2 : -6.4, ß3 : -0.37) significantly reduced after classification. Both annual tramadol utilisation and rate of tramadol-related deaths increased before tramadol classification and decreased thereafter. CONCLUSIONS: Increasing tramadol utilisation was influenced by the increase in prevalence and incidence of tramadol users, mean daily dose, and day of supply. Prevalence of tramadol users, tramadol utilisation, and reported deaths declined after tramadol classification. Future studies need to evaluate the influencing factors to ensure the safety of long-term tramadol use.