Explaining the variation between practices in the duration of new antidepressant treatment: a database cohort study in primary care

What proportion of initially prescribed antidepressants is still being prescribed chronically after 5 years in general practice? A longitudinal cohort analysis

OBJECTIVES

Antidepressant prescribing almost doubled in the Netherlands between 1996 and 2012, which could be accounted for by longer continuation after the first prescription. This might be problematic given a growing concern of large-scale antidepressant dependence. We aimed to assess the extent and determinants of chronic antidepressant prescribing among patient aged 18 years and older. We hypothesise a relatively large prevalence of chronic (>2 years) prescription.

DESIGN

A longitudinal observational study based on routinely registered prescription data from general practice.

SETTING

189 general practices in the Netherlands.

PARTICIPANTS

326 025 patients with valid prescription data for all 5 years of the study.

OUTCOME MEASURES

Primary outcome measure: the number of patients (N) receiving at least four antidepressant prescriptions in 2011, as well as during each of the four subsequent years. Secondary outcome measure: the above, but specified for selective serotonin reuptake inhibitors and for tricyclic antidepressants.

RESULTS

Antidepressants were prescribed to almost 7% of our 326 025 participants each year. They were prescribed for depression (38%), anxiety (17%), other psychological disorders (20%) and non-psychological indications (25%). Antidepressants were prescribed in all 5 years to the 42% of the population who had at least four prescriptions dispensed in 2011. Chronic prescribing was higher among women than men, for those aged 45-64 years than for those aged >65 years and for those treated for depression or anxiety than for non-psychological indications (eg, neuropathic pain). Chronic prescribing also varied markedly among general practices.

CONCLUSION

Chronic antidepressant use is common for depression and for anxiety and non-psychological diagnoses. Once antidepressants have been prescribed, general practitioners and other prescribers should be aware of the risks associated with long-term use and should provide annual monitoring of the continued need for therapy.

Average duration of treatment with antidepressants among concession card holders in Australia

OBJECTIVE

To analyse the average treatment duration with antidepressants that are reimbursed for concession card holders under the Pharmaceutical Benefits Scheme in Australia.

METHOD

This pharmacoepidemiological study was based on a representative 10% sample of patients receiving Pharmaceutical Benefits Scheme prescriptions. Antidepressants redeemed by concession card holders in the period from 2010 to 2013 were analysed. A 5-year baseline period was used to exclude prevalent users from incident users. Estimation of treatment duration was based on the epidemiological equation: prevalence/incidence = average duration. The mean value for prevalence and incidence over the studied period was used in the equation.

RESULTS

The number of prevalent and incident users increased from 90,475 to 103,305 and from 25,006 to 26,289, respectively. The epidemiological average treatment duration in the period was about 4 years. When considered by age-bands, average treatment duration was 2 years in patients under 24 years, 3 years in patients 35 to 44 years and up to 5 years in the 55 to 64 year age group. Of new users of antidepressants reimbursed under the Pharmaceutical Benefits Scheme, 86% received their first prescription from general practitioners, 4.3% from psychiatrists and 9.7% from other physicians.

CONCLUSION

While recommendations have underlined the importance of giving antidepressants for a sufficient period of time, the results from this study show that it is as important to remind general practitioners to review patients on antidepressant treatment regularly, and try to cease drug treatment when timely.

Did NICE guidelines and the Quality Outcomes Framework change GP antidepressant prescribing in England? Observational study with time trend analyses 2003-2013

BACKGROUND

Both the 2004 NICE depression guidelines and 2006 general practice Quality Outcomes Framework (QOF) encouraged improved targeting of antidepressant treatment for depression.

METHODS

Possible effects of the NICE guideline from January 2005, and QOF from April 2006, on rates of GP antidepressant prescribing were examined using time trend analyses of anonymised data from 142 English practices contributing to the Clinical Practice Research Datalink (CPRD), 2003-2013.

RESULTS

Sustained reductions were found in the proportion of first-ever depression episodes treated within 12 months, of 4.2% (95% C.I. 1.0-7.3%) following introduction of the NICE guideline, and 4.4% (2.3-6.5%) following introduction of the QOF. Treatment rates for first-ever episodes fell from 72.5% (70.8-74.1%) in Quarter 2 (Q2) 2003 to 61.0% (59.3-62.7%) in Q1 2012, but treatment rates for recurrent episodes increased from 74.3% (72.8-75.8%) to 77.8% (76.5-79.1%), so overall rates remained around 70%. Mean prescriptions per patient per year doubled from 2.06 (2.05-2.07) to 3.98 (3.97-3.99).

LIMITATIONS

Participating practices were larger than average and not representative across regions. Inferences of cause and effect from time trend analyses are subject to the possibility of unidentified confounders. No data were available on depression severity or appropriateness of prescribing.

CONCLUSIONS

Rates of GP antidepressant treatment for patients with incident depression fell following introduction of NICE depression guidelines and the QOF, but treatment rates for recurrent depression increased. Prescription numbers increased due to longer treatment courses. To impact on antidepressant prescribing rates, guidelines and performance indicators must address recurrent and long-term prescribing, rather than initial treatment decisions.

Restarting antidepressant treatment following early discontinuation--a primary care database study

BACKGROUND

Many patients in primary care stop antidepressant treatment after only one prescription, so do not benefit from treatment. Some patients who stop initial antidepressant treatment go on to restart it, but neither the incidence of restarting nor the probability that patients who restart treatment subsequently complete an adequate course of treatment is known.

OBJECTIVE

To examine subsequent antidepressant use in patients who discontinued treatment after only one antidepressant prescription.

METHODS

We used a primary care database (over 1.2 million records) to study patients who commenced treatment with an eligible antidepressant between April 2007 and March 2008 and who stopped treatment for at least 1 month after the first prescription. We examined their subsequent antidepressant prescriptions to estimate the probability of restarting antidepressant treatment, the likelihood of continuing subsequent treatment and the patient characteristics associated with these.

RESULTS

Out of 24817 patients, 6952 (28%) patients discontinued antidepressant treatment after the first prescription. The cumulative probability of restarting treatment after early discontinuation was 8.6% (95% confidence interval [CI] 8.0-9.3) after 1 month off-treatment, and 24.1% (22.9-25.2) after 9 months off-treatment. The probability of those who restarted treatment continuing for 6 months or more was 29.3% (26.5-32.5).

CONCLUSIONS

Few patients who stop antidepressant treatment after the first prescription subsequently complete an adequate treatment course within the next year. Initiatives to promote adherence to appropriate antidepressant treatment should begin during the first prescription.