Rise in Prescribing for Anxiety in UK Primary Care between 2003 and 2018

Rise in Prescribing for Anxiety in UK Primary Care between 2003 and 2018

Anxiety has become among the most common mental health concerns affecting patients in the UK, with a particular prevalence among young people. Numerous studies have found that anxiety rates have been on the rise across the population in recent years – findings supported by data collected over a 16-year period and presented in a recent study. The data shows a rise in prescribing for anxiety in primary care in the UK between 2003 and 2018.

Prescribing for Anxiety in the UK

Anxiety disorders are typically managed in primary care. The National Institute of Health and Care Excellence (NICE) recommends a four-step approach to anxiety treatment. Initially, this involves identification of anxiety as a problem and active monitoring. At step two, NICE recommends low-intensity psychological therapy. At step three, NICE recommends high-intensity psychological treatment or medications. Finally, step four is reserved for those with severe anxiety and incorporates complex drug and psychological therapies delivered by specialist multi-disciplinary teams. Various categories of medication may be employed to treat anxiety, including antidepressants, beta-blockers, benzodiazepines, anticonvulsants, and antipsychotics.

Prescribing of antidepressants for any indication has risen over the past two decades; however, this has been attributed to more long-term use as opposed to more patients starting medication. Antidepressant prescription for Generalised Anxiety Disorder (GAD) has also increased over the same period. In contrast, the number of patients prescribed benzodiazepines has declined since 2008 due to their potential for dependency.

Design and Methods of the Study

The current study examines trends in prescribing for anxiety in UK primary care between 2003 and 2018 using Clinical Practice Research Datalink (CPRD) data.

Researchers examined CRPD GOLD – a large database of anonymised UK primary care electronic records and used data from adults aged 18 and over who were registered at a CPRD GOLD practice between 1 January 2003 and 31st December 2018. Analyses were conducted for: any anxiolytic; any antidepressant; selective serotonin reuptake inhibitors (SSRIs) and ‘other antidepressants’; benzodiazepines; beta-blockers (propranolol); antipsychotics; and anticonvulsants (pregabalin and gabapentin).

Person-years-at-risk (PYAR) (the length of time an individual was considered at risk / receiving treatment) was calculated separately for prevalence and incidence analyses. Annual prevalence was calculated by dividing the total number of ‘cases’ by the total PYAR for each year included in the study.

The duration of treatment was also calculated for each drug. If no dosage instructions were provided, then the median of the substance-specific prescription duration was used. Duration was subdivided into categories (<15, 15–30, 31–60, 61–180, 181–365, and ≥366 days).

Results

The dataset used in this study included 176 practices with 2,569,153 eligible registered patients and 17.7 million PYAR. There were 546,154 anxiolytic prescribing events, of which 194,049 were starting prescriptions.

The prevalence of anxiolytic prescriptions was found to increase over the study period, with a marked rise between 2008 and 2018. Similar trends were observed in the prevalence for all antidepressant, SSRIs, and ‘other’ antidepressant prescriptions. The prevalence of beta-blocker prescribing also gradually increased between 2008 and 2018. On the other hand, the prevalence of benzodiazepines prescribing was lower, but remained steady over the 16-year period. Antipsychotics and anticonvulsants were prescribed infrequently.

Prescribing of anxiolytics, excluding antipsychotics, was more than twice as common in females than in males. The prescription of any anxiolytic, and antidepressants, and SSRIs and ‘other’ antidepressants were less prevalent in older adults. In contrast, the prescription of anticonvulsants was two to three times more prevalent in patients aged ≥25 years than in those aged <25 years. The prevalence of antipsychotic prescribing was 40% higher in those aged 25-40 than in those aged <25 years. Prevalence increased substantially in those aged 18-34 years in later years of the study across all drug classes.

Limitations

While the data used in this study demonstrates a general rise in prescribing for the treatment of anxiety across all drug classes, the researchers note some limitations with the study design.

Firstly, the study was restricted to patients who had a recorded anxiety code and anxiolytic prescription; data from patients who had been prescribed an anxiolytic but did not have an anxiety code were not included.

Secondly, although prescriptions must have occurred within the defined time period of an anxiety code, some of these drugs may have been prescribed for other indications. This means that the reported figures may be an overestimate.

Finally, the researchers note that increases in starting medications for anxiety, especially in young adults, may reflect “better detection of anxiety, increasing severity of symptoms or earlier unmet need.”

Researcher Conclusions

Previous research has found substantial increases in prescribing of antidepressants – for any indication and for depression – but this was attributed to increasing long-term use of antidepressants rather than increased incident prescribing. The researchers note that, in contrast, the present study found increases in incident antidepressant prescribing between 2013 and 2018. The findings of this study support those of other recent studies that have found a rise in the prevalence of anxiety disorders within the UK population.

The researchers note that the trends in anxiolytic prescribing over the study period may be linked to similar trends in diagnostic codes used by GPs over the same period (GPs are more likely to use diagnostic codes when anxiety is severe and are more likely to prescribe an anxiolytic when a patient has a diagnosis of anxiety.

The researchers conclude that more research is needed to improve our understanding about the reasons behind the rise in prescribing for anxiety and to “provide interventions that are acceptable and effective for young adults that can mitigate the growing reliance on pharmacotherapy for this age group.”