Antidepressant drug use in general practice: inter-practice variation and association with practice characteristics

Interpreting technology: Use and non-use of doctor-patient video consultations in Danish general practice

This study uses socio-cognitive theory on technological frames to understand how and why general practitioners in Denmark use or choose not to use video consultations. Video consultations play a vital role in the digitalisation of the Danish healthcare system. Whilst political decision-makers continuously push for increased use of video consultations, uptake accounts for less than 2% of all consultations. Research is needed that explores the actual circumstances and conditions of video consultation use. Our data corpus consists of 30 semi-structured interviews conducted from August 2021 to August 2022 with 27 Danish general practitioners. Interviews were analysed following reflexive thematic analysis. Our findings show that video consultations are interpreted as 1) compromising occupational values, 2) a crisis tool, 3) the future, and 4) a tool to improve work conditions. Video consultations are differently adopted across clinics due to different interpretations of the technology and its relative advantage in specific clinical contexts. We argue that the concept of technological frames offers a useful analytic perspective for elucidating and anticipating attitudes and actions towards a technology. It increases our understanding of the uptake and rejection of video consultations. This knowledge is valuable for clinicians and politicians working with technological innovation in general practice.

Analysis of Antidepressants Utilization for Patients Visiting Psychiatric Out-Patient Clinic in a Tertiary Care Hospital

Depression is a prevalent mental health condition treated with antidepressants and other psychotropic medications. This study aimed to assess the utilization pattern of antidepressants among patients visiting the outpatient clinic of the psychiatry department of a tertiary care hospital. The study included the patients who visited the study site and fulfilled the mental and behavioral diagnostic criteria for depression. The demographic and clinical details, including drugs prescribed, were documented in a study-specific data collection form. The ratio of Prescribed Daily Dose to Defined Daily Dose (PDD: DDD) was calculated to assess the adequacy of antidepressant utilization. Data total of 154 patients were collected. A total of 22 psychotropic drugs were used among the study patients as mono (n = 70), dual (n = 69), triple (n = 10), or quadruple therapy (n = 1). Escitalopram was the most often prescribed antidepressant out of the nine antidepressants alone and in combination and was used in slightly high doses (PDD: DDD ratio 1.6). Sertraline, paroxetine, and desvenlafaxine, were used in adequate doses (PDD: DDD between 1 and 1.1), and fluoxetine, duloxetine, amitriptyline, imipramine, and mirtazapine, were used in inadequate doses (PDD: DDD <0.5). Our study findings reveal the need for continuous assessment of antidepressants medications usage in a hospital set up.

Profiles of GPs with high and low self-reported physician empathy—personal, professional, and antibiotic prescribing characteristics

Background

General Practitioners’ (GPs) professional empathy has been hypothesized to have substantial impact on their healthcare delivery and medication prescribing patterns. This study compares profiles of personal, professional, and antibiotic prescribing characteristics of GPs with high and low empathy.

Methods

We apply an extreme group approach to a unique combined set of survey and drug register data. The survey included questions about demographic, professional, and antibiotic prescribing characteristics, as well as the Jefferson Scale of Empathy for Health Professionals (JSE-HP) to assess self-reported physician empathy. It was sent to a stratified sample of 1,196 GPs comprising 30% of the Danish GP population of whom 464 (38.8%) GPs responded. GPs in the top and bottom decile of empathy levels were identified. All intra- and inter-profile descriptive statistics and differences were bootstrapped to estimate the variability and related confidence intervals. 

Results

61% of GPs in the top decile of the empathy score were female. GPs in this decile reported the following person-centered factors as more important for their job satisfaction than the bottom decile: The Patient-physician relationship, interaction with colleagues, and intellectual stimulation. High-empathy scoring GPs prescribed significantly less penicillin than the low-empathy GPs. This was true for most penicillin subcategories. There were no significant differences in age, practice setting (urban vs. rural), practice type (partnership vs. single-handed), overall job satisfaction, or GP’s value of prestige and economic profit for their job satisfaction. The intra profile variation index and confidence intervals show less prescribing uncertainty among GPs with high empathy.

Conclusions

This study reveals that high empathy GPs may have different personal, professional, and antibiotic prescribing characteristics than low empathy GPs and have less variable empathy levels as a group. Furthermore, person-centered high empathy GPs on average seem to prescribe less penicillins than low empathy GPs.

The stratified medicalisation of mental health symptoms: educational inequalities in the use of psychotropic medication in Belgium

PURPOSE

Several studies have shown socioeconomic inequalities in psychotropic medication use, but most of these studies are inspired by Andersen's behavioural model of health care use, which strongly focusses on individuals' needs. Andersen's model pays little attention to health care use that is not based on need and insubstantially recognises the context dependentness of individuals. Medicalisation, however, is a context-dependent interactive process that not only interacts with need determinants, but also with non-need determinants that affect health care use. Therefore, this study will examine if psychotropic medication use is stratified, and whether this is not simply the result of differences in need for care, but also influenced by factors not based on need, initiating the stratified medicalisation of mental health symptoms.

METHODS

Data from the Belgian Health Interview Survey (BHIS) are used. This study covers information from five successive waves: 2001, 2004, 2013, 2018. The weighted data represent a sample of the adult Belgian population. The research aims are analysed using stepwise Poisson regression models, where the models are also plotted to detect evolutions over time, using marginal means postestimation.

RESULTS

The results reveal that educational inequalities in psychotropic medication use are significant and persistently visible over time. Even after entering need for care, educational inequalities remain significant.

CONCLUSION

This study shows that psychotropic medication use is stratified and that this is not simply the result of differences in need for care, but also influenced by factors linked to the stratified medicalisation of mental health symptoms.

Visualizing nationwide variation in medicare Part D prescribing patterns

Background

To characterize the regional and national variation in prescribing patterns in the Medicare Part D program using dimensional reduction visualization methods.

Methods

Using publicly available Medicare Part D claims data, we identified and visualized regional and national provider prescribing profile variation with unsupervised clustering and t-distributed stochastic neighbor embedding (t-SNE) dimensional reduction techniques. Additionally, we examined differences between regionally representative prescribing patterns for major metropolitan areas.

Results

Distributions of prescribing volume and medication diversity were highly skewed among over 800,000 Medicare Part D providers. Medical specialties had characteristic prescribing patterns. Although the number of Medicare providers in each state was highly correlated with the number of Medicare Part D enrollees, some states were enriched for providers with > 10,000 prescription claims annually. Dimension-reduction, hierarchical clustering and t-SNE visualization of drug- or drug-class prescribing patterns revealed that providers cluster strongly based on specialty and sub-specialty, with large regional variations in prescribing patterns. Major metropolitan areas had distinct prescribing patterns that tended to group by major geographical divisions.

Conclusions

This work demonstrates that unsupervised clustering, dimension-reduction and t-SNE visualization can be used to analyze and visualize variation in provider prescribing patterns on a national level across thousands of medications, revealing substantial prescribing variation both between and within specialties, regionally, and between major metropolitan areas. These methods offer an alternative system-wide and pattern-centric view of such data for hypothesis generation, visualization, and pattern identification.

Electronic supplementary material

The online version of this article (10.1186/s12911-018-0670-2) contains supplementary material, which is available to authorized users.

Mental illness in primary care: a narrative review of patient, GP and population factors that affect prescribing rates

BACKGROUND

Mental illness poses a large and growing disease burden worldwide. Its management is increasingly provided by primary care. The prescribing of psychotropic drugs in general practice has risen in recent decades, and variation in prescribing rates has been identified by a number of studies. It is unclear which factors lead to this variation.

AIM

To describe the variables that cause variation in prescribing rates for psychotropic drugs between general practices.

METHODS

A narrative review was conducted in January 2018 by searching electronic databases using the PRISMA statement. Studies investigating causal factors for variation in psychotropic prescribing between at least two general practice sites were eligible for inclusion.

RESULTS

Ten studies met the inclusion criteria. Prescribing rates varied considerably between practices. Positive associations were found for many variables, including social deprivation, ethnicity, patient age and gender, urban location, co-morbidities, chronic diseases and GP demographics. However studies show conflicting findings, and no single regression model explained more than 57% of the variation in prescribing rates.

DISCUSSION

There is no consensus on the factors that most predict prescribing rates. Most research was conducted in countries with central electronic databases, such as the United Kingdom; it is unclear whether these findings apply in other healthcare systems. More research is needed to determine the variables that explain prescribing rates for psychotropic medications.

Prevalence and sociodemographic patterns of antidepressant use among women of reproductive age: a prescription database study

BACKGROUND

There has been a steady increase in the prescription of antidepressants in developed countries in recent decades. Antidepressant treatment prevalence and sociodemographic pattern data can inform the review of clinical guidelines for depression treatment. We determined the one-year prevalence and sociodemographic pattern of antidepressant dispensing among women of childbearing age (15-45 years) in Northern Ireland (NI).

METHODS

A cross-sectional study using individual electronic prescribing data for 2009. Our study population was 268,917 women of childbearing age (15-45 years), with/without prescriptions, registered with the 246 out of 363GP practices in NI with high electronic prescribing data coverage. Socioeconomic deprivation (in quintiles) was measured by an area indicator attached to residential postcode.

RESULTS

The one-year prevalence of redeemed antidepressant prescriptions was 16.3% (95% CI 16.1-16.4). More than two-thirds of antidepressant prescriptions were for SSRIs. Thirty-five per cent of the women who redeemed prescriptions for antidepressants also redeemed prescriptions for psycholeptics within 2 months of the antidepressant prescriptions. Redeemed antidepressant prescription prevalence increased from 4.8% (15-19 years) to 24.6% (40-45 years), from 13.5% (quintile 1, least deprived) to 20.7% (quintile 5, most deprived), and with urbanity of GP practice location.

LIMITATION

Only GP practices with high capture of electronic prescribing data were included, which may not be entirely representative of NI. We could not assess the appropriateness of prescribing according to national guidelines.

CONCLUSIONS

Antidepressant use is high among women of childbearing age in NI and increases with age and socioeconomic deprivation. This reinforces the need to address the determinants of depression, and assess the appropriateness of treatment policies and practices.

How do GP practices and patient characteristics influence the prescription of antidepressants? A cross-sectional study

BACKGROUND

Under-prescription of antidepressants (ADs) among people meeting the criteria for major depressive episodes and excessive prescription in less symptomatic patients have been reported. The reasons influencing general practitioners' (GPs) prescription of ADs remain little explored. This study aimed at assessing the influence of GP and patient characteristics on AD prescription.

METHODS

This cross-sectional study was based on a sample of 816 GPs working within the main health care insurance system in the Seine-Maritime district of France during 2010. Only GPs meeting the criteria for full-time GP practice were included. The ratio of AD prescription to overall prescription volume, a relative measure of AD prescription level, was calculated for each GP, using the defined daily dose (DDD) concept. Associations of this AD prescription ratio with GPs' age, gender, practice location, number of years of practice, number of days of sickness certificates prescribed, number of home visits and consultations, number and mean age of registered patients, mean patient income, and number of patients with a chronic condition were assessed using univariate and multivariate analysis.

RESULTS

The high prescribers were middle-aged (40-59) urban GPs, with a moderate number of consultations and fewer low-income and chronic patients. GPs' workload (e.g., volume of prescribed drug reimbursement and number of consultations) had no influence on the AD prescription ratio. GPs with more patients with risk factors for depression prescribed fewer ADs, however, which could suggest the medications were under-prescribed among the at-risk population.

CONCLUSIONS

Our study described a profile of the typical higher AD prescriber that did not include heavy workload. In future work, a more detailed assessment of all biopsychosocial components of the consultation and other influences on GP behavior such as prior training would be useful to explain AD prescription in GP's practice.

Antidepressant prescribing in five European countries: application of common definitions to assess the prevalence, clinical observations, and methodological implications

PURPOSE

Drug utilization studies have applied different methods to various data types to describe medication use, which hampers comparisons across populations. The aim of this study was to describe the time trends in antidepressant prescribing in the last decade and the variation in the prevalence, calculated in a uniform manner, in seven European electronic healthcare databases.

METHODS

Annual prevalence per 10,000 person-years (PYs) was calculated for 2001-2009 in databases from Spain, Germany, Denmark, the United Kingdom (UK), and the Netherlands. Prevalence data were stratified according to age, sex, antidepressant type (selective serotonin re-uptake inhibitors [SSRIs] or tricyclic antidepressants [TCAs]) and major indications.

RESULTS

The age- and sex-standardized prevalence was lowest in the two Dutch (391 and 429 users per 10,000 PYs) and highest in the two UK (913 and 936 users per 10,000 PYs) populations in 2008. The prevalence in the Danish, German, and Spanish populations was 637, 618, and 644 users per 10,000 PY respectively. Antidepressants were prescribed most often in 20- to 60-year-olds in the two UK populations compared with the others. SSRIs were prescribed more often than TCAs in all except the German population. In the majority of countries we observed an increasing trend of antidepressant prescribing over time. Two different methods identifying recorded indications yielded different ranges of proportions of patients recorded with the specific indication (15-57% and 39-69% for depression respectively).

CONCLUSION

Despite applying uniform methods, variations in the prevalence of antidepressant prescribing were obvious in the different populations. Database characteristics and clinical factors may both explain these variations.

Presynaptic selectivity of a ligand for serotonin 1A receptors revealed by in vivo PET assays of rat brain

A novel investigational antidepressant with high affinity for the serotonin transporter and the serotonin 1A (5-HT(1A)) receptor, called Wf-516 (structural formula: (2S)-1-[4-(3,4-dichlorophenyl)piperidin-1-yl]-3-[2-(5-methyl-1,3,4-oxadiazol-2-yl)benzo[b]furan-4-yloxy]propan-2-ol monohydrochloride), has been found to exert a rapid therapeutic effect, although the mechanistic basis for this potential advantage remains undetermined. We comparatively investigated the pharmacokinetics and pharmacodynamics of Wf-516 and pindolol by positron emission tomographic (PET) and autoradiographic assays of rat brains in order to elucidate their molecular interactions with presynaptic and postsynaptic 5-HT(1A) receptors. In contrast to the full receptor occupancy by pindolol in PET measurements, the binding of Wf-516 to 5-HT(1A) receptors displayed limited capacity, with relatively high receptor occupancy being achieved in regions predominantly containing presynaptic receptors. This selectivity was further proven by PET scans of neurotoxicant-treated rats deficient in presynaptic 5-HT(1A) receptors. In addition, [(35)S]guanosine 5'-O-[γ-thio]triphosphate autoradiography indicated a partial agonistic ability of Wf-516 for 5-HT(1A) receptors. This finding has lent support to reports that diverse partial agonists for 5-HT(1A) receptors exert high sensitivity for presynaptic components. Thus, the present PET data suggest a relatively high capacity of presynaptic binding sites for partial agonists. Since our in vitro and ex vivo autoradiographies failed to illustrate these distinct features of Wf-516, in vivo PET imaging is considered to be, thus far, the sole method capable of pharmacokinetically demonstrating the unique actions of Wf-516 and similar new-generation antidepressants.

Antidepressants utilization among elderly in Lombardy from 2000 to 2007: dispensing trends and appropriateness

PURPOSE

To investigate the prevalence and incidence of antidepressant (AD) use in the elderly during an 8-year period and to evaluate AD treatment appropriateness.

METHODS

A population-based dispensation study on community-dwelling elderly of a large area in Lombardy was performed. Data were drawn from the regional administrative database and from a general practice registry. For each year, prevalence of AD use (i.e., at least one recorded dispensation) and AD treatment (i.e., at least four recorded dispensations) was compared.

RESULTS

The prevalence of AD use and treatment doubled and tripled, respectively. The greatest shift occurred between 2000 and 2002 and was entirely due to SSRIs. The most pronounced increase was seen in females who accounted for 72% of all dispensations. The increase in prevalence was not mirrored by incident use, which slightly decreased (OR: 0.98; 95% CI: 0.98-0.98). The proportion of those who received a minimally adequate AD treatment grew over the years (OR: 1.63; 95% CI: 1.59-1.68). The increase in prevalence of AD treatment was most pronounced among older age groups (ORs between 1.02 and 1.06 for age classes ≥75 years relative to the 65-69 age class; P < 0.001) and was proportional to that of depressive disorders.

CONCLUSIONS

A dramatic rise in dispensations was observed. The increasing prevalence of minimally adequately treated subjects and a possible decrease in untreated depression may reflect an improvement in the pharmacological treatment of depression. The increase in prevalence and not in the incidence of dispensations could be related to an inappropriate prolongation of treatment duration.

[Variations in antihypertensive drug utilization among primary care areas in the autonomous region of Valencia (Spain)]

OBJECTIVES

To estimate consumption of five subgroups of antihypertensive drugs by primary care areas and to analyze its variation.

METHODS

We performed an ecological, descriptive study of antihypertensive consumption in 239 primary care areas in the autonomous region of Valencia in 2005 followed by analysis of the variability observed. The 239 primary care areas were studied by descriptive analysis of dispensation [defined daily dose (DDD) per 1,000 inhabitants/day in pensioners (DDD/1000p/day) and in the active population (DDD/1000a/day)] and standardized consumption ratios. Small-area variation analysis was used to analyze the observed variability. Associations among dispensations of the distinct therapeutic subgroups were also analyzed.

RESULTS

Overall antihypertensive use in the autonomous region of Valencia in 2005 was 235.6DDD/1000/day. This consumption was concentrated in pensioners (800DDD/1000p/day vs. 73DDD/1000a/day). Consumption of antihypertensive subgroups oscillated from 442DDD/1000p/day for drugs with action on the renin-angiotensin system to 32DDD/1000p/day for doxazosin. The active population showed similar patterns. Variation in consumption was moderate, with coefficients of variation from 0.20 to 0.40 (slightly greater for the active population). Associations among dispensations of the different therapeutic subgroups were strong.

CONCLUSIONS

This study shows major variations in the overall consumption of antihypertensive drugs among primary care areas of the autonomous region of Valencia. These results suggest that variation may be associated with problems of underutilization in areas with lower consumption.

Acute and continuation therapy in unipolar depression: observations from the run-in phase of a maintenance trial

OBJECTIVE

The aim of the study was to analyze treatments and outcome in depressed patients.

METHOD

Patients with recurrent depressive disorder (n = 289), recruited for a prophylaxis study, were followed up in hospital settings for 6 months with diagnostic and depression ratings at baseline and monthly depression ratings. Data on psychotropic drugs were retrieved from hospital case records. Independent associations between baseline, treatment and outcome variables were examined by logistic regression models.

RESULTS

Depressive symptoms subsided gradually. After 6 months, 21% had dropped out, 43% were rated as remitted (HAM-D-17 <8) and 8% had not responded (HAM-D-17 >15). Patients once remitted rarely relapsed (<5%). All patients received antidepressant drugs, half of them more than one (2-4) as well as other psychotropic drugs. Patients responding poorly received more frequently multiple antidepressants, tricyclic antidepressants, hypnosedatives, lithium and/or antipsychotics.

CONCLUSION

The 6-month outcome was generally poor. Choice of treatment appeared at least partly to be determined by the therapeutic outcome.

Tamoxifen's protection against breast cancer recurrence is not reduced by concurrent use of the SSRI citalopram

Tamoxifen remains an important adjuvant therapy to reduce the rate of breast cancer recurrence among patients with oestrogen-receptor-positive tumours. Cytochrome P-450 2D6 metabolises tamoxifen to metabolites that more readily bind the oestrogen receptor. This enzyme also metabolises selective serotonin reuptake inhibitors (SSRI), so these widely used drugs – when taken concurrently – may reduce tamoxifen's prevention of breast cancer recurrence. We studied citalopram use in 184 cases of breast cancer recurrence and 184 matched controls without recurrence after equivalent follow-up. Cases and controls were nested in a population of female residents of Northern Denmark with stages I–III oestrogen-receptor-positive breast cancer 1985–2001 and who took tamoxifen for 1, 2, or most often for 5 years. We ascertained prescription histories by linking participants' central personal registry numbers to prescription databases from the National Health Service. Seventeen cases (9%) and 21 controls (11%) received at least one prescription for the SSRI citalopram while taking tamoxifen (adjusted conditional odds ratio=0.85, 95% confidence interval=0.42, 1.7). We also observed no reduction of tamoxifen effectiveness among regular citalopram users (⩾30% overlap with tamoxifen use). These results suggest that concurrent use of citalopram does not reduce tamoxifen's prevention of breast cancer recurrence.

Patterns and prevalence of antidepressant drug use in the German state of Baden-Wuerttemberg: a prescription-based analysis

PURPOSE

Population-based data about patterns and prevalence of antidepressant drug use is limited in Europe and presently unavailable for Germany. Therefore, we have identified patterns and prevalence of antidepressant use among outpatients on a population-based scale in the German state of Baden-Wuerttemberg.

METHODS

We conducted a historical cohort study using a computerised prescription database referring to all members of the major German public health insurance company AOK. We assessed the prevalence of antidepressant drug use over a 3-year period, calculated the number of prescription items purchased per patient and compared first-line and second-line treatments.

RESULTS

The 1-year prevalence of antidepressant drug use among more than 4,000,000 health insurance members was 7.4% (male: 4.3%; female: 10.2%). Importantly, almost 40% of the patients received only a single prescription item from 2000 to 2002. Though the use of serotonin-reuptake inhibitors (SSRIs) markedly increased by about 65% within the study period, these are primarily used as second-line drugs and still much less frequently than St. John's wort or tricyclic antidepressants such as amitryptiline or doxepin.

CONCLUSIONS

The prevalence of antidepressant drug use is higher than previously reported for other European countries. The preferred use of St. John's wort and tricyclics over SSRIs and other modern-type antidepressants in Germany is quite unique in Europe and different from the US. The identified drug use pattern leaves a major room for improvement in view of the numerous single prescription items purchased.

International study on antidepressant prescription pattern at 20 teaching hospitals and major psychiatric institutions in East Asia: Analysis of 1898 cases from China, Japan, Korea, Singapore and Taiwan

The purpose of the present study was to review the prescription patterns of antidepressants in different countries in East Asia. The survey was conducted in China, Japan, Korea, Singapore and Taiwan from October 2003 to March 2004 using the unified research protocol and questionnaire. Twenty teaching hospitals and major psychiatric hospitals participated and a total of 1898 patients receiving antidepressants were analyzed. The survey provided a number of interesting characteristics on the prescription patterns of antidepressant in East Asia. Out of 56 antidepressants listed in the Anatomical Therapeutic Chemical Classification (ATC) index by the World Health Organization (WHO) Collaborating Center for Drug Statistics Methodology (Oslo), only 26 antidepressants were prescribed in participating countries in East Asia. On average 38.4% of prescriptions of antidepressants were for patients with diagnoses other than depressive disorders. The availability and commonly prescribed antidepressants varied greatly by country. The selective serotonin re-uptake inhibitors (SSRI) and other newer antidepressants were prescribed in approximately 77.0% of all cases. At the time of the survey, only two SSRI medications were available in Japan. However, five types of SSRI were available and were often prescribed in Korea.

Clinical interest: a study of the influence on general practitioners' prescribing

PURPOSE

To analyse the association between general practitioners' clinical interest and prescribing rates in four clinical areas: dyspepsia, depression, headache and diabetes.

METHODS

Data concerning general practitioners' prescribing during 2004 were retrieved from a pharmacy database and linked with data from a physician questionnaire and the National Health Insurance Register. To counterbalance differences in practice populations all 1-year prevalences of prescribing were standardised according to age and gender. Participants were asked 'To what extent do you find the following areas interesting from a professional point-of- view?' Four rating categories were used. The association between clinical interest and standardised prescribing rates was investigated using logistic regression, the Kruskal-Wallis test and a trend test.

RESULTS

A total of 68 (72%) single-handed general practitioners representative of the total group completed the questionnaire. We observed a two-fold ratio between the 90% and the 10% percentiles of the 1-year prevalences of antisecretory drugs, antidepressants, migraine drugs as well as anti-diabetics. The variation in prescribing of antidepressant and antisecretory drugs was far above chance level. No significant association with clinical interest could, however, be observed for any of the four clinical areas.

CONCLUSION

General practitioners' prescribing of the four classes of medical drugs varied considerably. However, only part of this variation was based on chance. This study did not confirm our hypothesis that general practitioners' level of clinical interest in one area corresponds with their prescribing of drugs used within that area.

Indications for antidepressant drug prescribing in general practice in the Netherlands

BACKGROUND

The intensity of the use of antidepressants in large populations can nowadays relatively easily be estimated using databases encompassing prescription data. There are shortcomings when using prescription databases as they contain no clinical data on patient illness. Antidepressants are prescribed for different illnesses, thus information on the indications could help when interpreting results from database studies on antidepressant drug use. The aim of this study is to investigate for which indications antidepressants are being prescribed in general practice in the Netherlands.

METHODS

Data were obtained from the Second Dutch National Survey of General Practice, carried out by NIVEL (N=385,461). Patients, 18 years and older, who received an antidepressant prescription from a general practitioner in 2001 were selected (N=13,835). Indications for antidepressant drug prescribing were identified using time windows of different lengths.

RESULTS

Antidepressants are most often being prescribed for depression (45.5%) and anxiety/panic disorders (17.2%). For these indications lengthening the time window around prescription date from 0 to 180 days resulted in an increase of 20-40% in antidepressant drug users identified with these indications.

LIMITATION

None of our selected indications could be identified in the physician-patient contact file for about a third of the antidepressant drug users. The study was performed in a general practice setting and did not include antidepressant users who consult psychiatrists.

CONCLUSION

GPs prescribe antidepressants predominantly for treating depression. However, using antidepressant drug as a proxy for identifying depressed patients in a prescription database should be done with caution and when possible in combination with clinical data.

Newer antidepressant drug use in East Asian psychiatric treatment settings: REAP (Research on East Asia Psychotropic Prescriptions) Study

AIMS

Antidepressant use in East Asia is poorly documented. We compared patients given newer and older antidepressants to test the hypothesis, suggested in the literature, that use of newer antidepressants is associated with treatment settings rather than specific diagnostic categories.

METHODS

We compared rates of use of older (pre1990) vs. newer antidepressants among 1898 patients identified as antidepressant treated at 21 centres in five East Asian countries (China, Japan, Korea, Singapore, Taiwan) in 2003. Demographics, treatment setting and clinical factors associated with preferential use of newer drugs were tested in univariate and multivariate analyses.

RESULTS

Newer antidepressants were included in the treatment regimens of 67.5% (N = 1282/1898) of study subjects. Prescription for newer antidepressants was significantly associated with younger age (z = -4.55, d.f. = 1888, P < 0.001), hospitalization [odds ratio (OR) 1.32, 95% confidence interval (CI) 1.07, 1.64, P < 0.01] and treatment within psychiatric hospitals (OR 1.59, 95% CI 1.27, 2.00, P < 0.001). On multivariate analyses, treatment with newer antidepressants was independently associated with younger age (P < 0.001), country (P < 0.001) and treatment within private hospitals (P < 0.001), but not with sex or diagnosis of affective or anxiety disorders (all P > 0.1).

CONCLUSION

Demographic factors and treatment settings appear to influence antidepressant choice more than clinical factors such as diagnosis.

Prevalence and patterns of antidepressant drug use during pregnancy

OBJECTIVE

The aim of this study was to determine the extent and patterns of antidepressant use before, during and after pregnancy in a large population in The Netherlands.

METHODS

Health care records and prescription data from one of the largest Dutch health insurance companies were analysed. The study cohort consisted of 29,005 women who had live births in the period between January 2000 and July 2003. Antidepressant drug use during a specified period was defined as there being a record of a prescription during that period.

RESULTS

During the first trimester of pregnancy 2% of all pregnant women of the study cohort were found to have taken antidepressants; in the second and third trimesters, this figure had dropped to 1.8% of all pregnancies. Antidepressant use before as well as during pregnancy was almost twofold higher in women over 35 years of age than in those under 35 years. Almost 60% of the women who used antidepressants before pregnancy stopped taking them in the first trimester, and a smaller number stopped thereafter. Of all women using antidepressants during pregnancy, one third started this medication during gestation. In the 3 months following delivery, the prevalence of antidepressant use was the same as before pregnancy (2.9%). There was no shift to benzodiazepines in the group of women who stopped taking antidepressants during pregnancy. Although paroxetine and fluoxetine were the most frequently used antidepressants among the study group, all modern antidepressants were used.

CONCLUSION

A considerable number of women are being exposed to antidepressants throughout pregnancy up until delivery. One consequence of this is that their newborns need special care and supervision during the first days of life. However, women who stop taking the medication may risk a relapse of their illness, and this may also have a negative effect on the child.

Potential bias in pharmacoepidemiological studies due to the length of the drug free period: a study on antidepressant drug use in adults in the Netherlands

PURPOSE

The aim of this study was to evaluate the effect of the length of the drug free period on incidence measurements as well as on cohort characteristics in users of antidepressants.

METHODS

The study population consisted of patients aged 18 years or older who filled a prescription for an antidepressant drug in the Netherlands, between October 2001 and September 2002. One-year incidence of antidepressant drug use was estimated using drug free periods varying in length from 1 month to 9 years. In addition, we evaluated what effect the drug free period has on cohort characteristics by comparing a cohort of first time antidepressant drug users defined using a 9-year drug free period with cohorts using 6, 12 and 24 months drug free period.

RESULTS

When using a 6-month drug free period the measured incidence was about 32 per 1,000 individuals (95%CI: 31.3, 32.6) while the measured incidence was 27.5 (95%CI: 26.9, 28.1), 23.5 (95%CI: 22.9, 24.0) and 17.2 (95%CI: 16.7, 17.7) per 1,000 individuals when using a 12-month, 24 month respectively a 9-year drug free period. Furthermore, the prevalence of characteristics in inception cohort studies changes when using different drug free periods.

CONCLUSION

Altering the drug free period from a short to a longer one results in decreased incidence. Furthermore, for inception cohorts where first time drug use is an inclusion criterion the drug free period can influence the prevalence of cohort characteristics and for short drug free periods give biased estimates.