Biomedical subjects
Andrea Mant
Publications and source records attributed to Andrea Mant.
Making new choices about antidepressants in Australia: the long view 1975-2002.
OBJECTIVE: To examine trends in types of antidepressant medications prescribed in Australia between 1975 and 2002. DESIGN: Sales data from the Australian pharmaceutical industry were used to examine trends in overall antidepressant prescribing and changes in the types of antidepressants prescribed between 1975 and 2002. MAIN OUTCOME MEASURES: Antidepressant sales were expressed as defined daily doses (DDDs) per 1000 people per day, using the estimated Australian population for each year obtained from the Australian Bureau of Statistics. RESULTS: Average annual growth in the sales of antidepressants was 1.1% per year from 1975 to 1990, after which growth rose steeply to reach 29% in 1995. By 2002 the rate of growth had slowed to 6.6%. Eighty per cent of total sales were accounted for by four drugs in 1975, 1980 and 1985; five in 1990; seven drugs in 1995 and 2000; and six drugs in 2001 and 2002. CONCLUSIONS: The rapid growth in antidepressant prescribing that was characteristic of the early 1990s, and reflected the emergence of new classes of agents, did not continue into the late 1990s. Selective serotonin reuptake inhibitors now dominate antidepressant prescribing in Australia.
Length of therapy with selective serotonin reuptake inhibitors and tricyclic antidepressants in Australia.
OBJECTIVE: To investigate the proportion of patients starting on either selective serotonin reuptake inhibitors (SSRIs) or tricyclic antidepressants (TCAs) who continued treatment for a period consistent with recommended guidelines for major depression, that is at least 6 months. METHOD: Cohort study using a national dispensing claims database involving patients eligible for social security entitlements in Australia. Two 'new user' cohorts were established of patients who were supplied a prescription for either an SSRI (6026) or a TCA (4158) in the first week of April 2000 and who had not received a prescription for any antidepressant in the preceding three months. The main outcome measure was the proportion of patients who were still having any SSRI or TCA prescription, respectively, dispensed between 6 and 8 months after initiation. Additionally, for patients starting on either a leading SSRI (sertraline) or TCA (dothiepin), the proportions of those that remained on these drugs or had changed to other antidepressants were determined. The dispensing data are not linked to reason for prescribing in the national dataset. RESULTS: 2267 SSRI 'new users' (38%) were still receiving SSRIs 6-8 months later, compared with 1269 (31%) of the 4158 TCA 'new users' (p < 0.001). The difference between the groups occurred early, by the 2-4 month time interval. 1038 (41%) of patients starting on the individual SSRI and 385 (38%) of patients starting on the individual TCA were receiving some type of antidepressant therapy at 6-8 months, with no significant difference (p = 0.6) in the proportions that had changed to another antidepressant. CONCLUSIONS: In 2000, only 40% of patients started on an antidepressant continued to be prescribed some antidepressant therapy 6-8 months later. Patients were more likely to continue on SSRIs as a class than on TCAs and the difference in continuation between these two classes occurred within the first 2 months of therapy. However, patients starting on an individual SSRI or TCA were equally likely to change to another antidepressant.
Lessons from early large-scale adoption of celecoxib and rofecoxib by Australian general practitioners.
OBJECTIVE: To assess trends in the first two years of prescribing of COX-2-selective non-steroidal anti-inflammatory drugs (C2SNs) by Australian general practitioners. DESIGN: Retrospective analysis of deidentified electronic patient records from GPs enrolled in the General Practice Research Network (GPRN). SETTING AND PARTICIPANTS: Overall prescription rates for C2SNs and NSAIDs were assessed for all GPRN participants (437 GPs) between 1 September 1999 and 30 September 2002. Also, three cohorts of patients, with at least 12 months of prescription data, who received their first prescription for celecoxib between August and October 2000 (Cohort 1, 2366 patients), celecoxib between February and April 2001 (Cohort 2, 640 patients), and rofecoxib between February and April 2001 (Cohort 3, 608 patients) were selected for further analysis. MAIN OUTCOME MEASURES: Age and sex of patients; reason for prescription; previously prescribed pain medications and concomitant use of medications that could predispose to an adverse renal or bleeding event. RESULTS: Prescriptions for C2SNs increased dramatically after they were listed on the Pharmaceutical Benefits Scheme (PBS). C2SN prescriptions for patients aged less than 65 years accounted for 52.6%, 59.5% and 50.7% of those in Cohorts 1, 2 and 3, respectively; large numbers of patients in the study cohort had reasons recorded for prescription that did not comply with PBS restrictions, and between 36.7% and 61.3% of patients in the three cohorts had not received a prescription for any pain medication in the year before being prescribed a C2SN. Between 4.7% and 7.9% were coprescribed drugs that could cause renal complications. CONCLUSIONS: Rapid, early adoption of C2SNs by Australian GPs has resulted in prescribing and drug use patterns that were not in accord with quality use of medicine (QUM) principles.
Association between antidepressant prescribing and suicide in Australia, 1991-2000: trend analysis.
OBJECTIVE: To examine the association between trends in antidepressant prescribing and suicide rates in Australia for 1991-2000. DESIGN: Analysis of databases of suicide and rates of antidepressant prescribing according to age and sex. SETTING: Australian Bureau of Statistics data, sales data from the Australian pharmaceutical industry, prescribing data in general practice. SUBJECTS: Men and women aged 15 years and over in 10 year age groups. MAIN OUTCOME MEASURES: Trends in suicide rates and trends in antidepressant prescribing. Association measured by Spearman's rank correlations. RESULTS: While overall national rates of suicide did not fall significantly, incidence decreased in older men and women and increased in younger adults. In both men (r(s)=-0.91; P<0.01) and women (r(s)=-0.76; P<0.05) the higher the exposure to antidepressants the larger the decline in rate of suicide. CONCLUSIONS: Changes in suicide rates and exposure to antidepressants in Australia for 1991-2000 are significantly associated. This effect is most apparent in older age groups, in which rates of suicide decreased substantially in association with exposure to antidepressants. The increase in antidepressant prescribing may be a proxy marker for improved overall management of depression. If so, increased prescribing of selective serotonin reuptake inhibitors in general practice may have produced a quantifiable benefit in population mental health.
Use of antidepressants by general practitioners and psychiatrists in Australia.
OBJECTIVE: To examine the antidepressant prescribing patterns of psychiatrists and general practitioners (GPs) in Australia, focusing specifically on: the prescribed daily dose, the relative proportions (from subsidized dispensing data) of prescriptions written, and how these proportions change over time for a newly listed antidepressant drug (using paroxetine as an example). METHOD: Retrospective analyses of subsidized claims data (comprising nearly 90% of the community supply of antidepressants) and prescriber surveys. RESULTS: General practitioners prescribe 86% of subsidized antidepressants in Australia. Almost three-quarters of the antidepressant prescriptions prescribed in primary care management are also initiated by a GP. Psychiatrists prescribed higher doses than general practitioners for all the antidepressants examined. For paroxetine, a higher than average proportion of scripts were written by psychiatrists when the drug was initially available and it only reached the GP/psychiatrist split seen with an established drug in the same therapeutic class (fluoxetine) four years after marketing. The most prominent type of depression that GPs believed they were treating was 'chronic mild depression', which contrasts with the subsidized indication for all newer antidepressant classes of 'major depressive disorders'. CONCLUSIONS: General practitioners are the major providers of treatment for depression in Australia. When writing prescriptions for tricyclic antidepressants GPs use doses lower than those recommended for major depression, however, most management in primary care is not for conditions regarded by the GP as major depression. A significant number of prescriptions for the newer antidepressants may not accord with the Pharmaceutical Benefits Scheme (PBS) restrictions for use.
A 5-year follow-up of general practice patients experiencing depression.
BACKGROUND: Depression is a common disease in primary care and produces significant morbidity in the community. Little is known about the outcomes of depression in general practice. OBJECTIVES: This research set out to explore both the longitudinal management and outcomes of depression as seen in general practice. METHODS: The Medic-GP database is a collection of the medical records of >50 000 people seen in nine Australian general practices. It was used to follow the management of depressed patients over 4-5 years. Records from 1994-1995 were searched for depression or similar words. Individual records of patients whose notes mentioned depression were randomly selected and examined to determine if they were diagnosed with depression. Records of patients who were diagnosed as suffering from depression were examined to determine progress over the ensuing 5 years. RESULTS: Six hundred of 5889 patients were examined in detail. A total of 382 patients (63.7%) were diagnosed with depression; 219 had been diagnosed during this time interval. The main findings were 64.7% of patients were female; 93.6% of patients received an antidepressant at some time during the study; 16% of patients were referred to a psychiatrist; 7.3% were hospitalized; 30% of patients who ceased antidepressants without a recurrence had courses of antidepressants of 3 months or less; and only 22.5% of patients had a single episode of depression. CONCLUSION: Unlike cross-sectional studies, this study has shown a high rate of prescription of antidepressants. GPs often prescribed short courses of antidepressants, and depression behaves as a chronic, recurrent disease.
A quality use of medicines program for continuity of care in therapeutics from hospital to community.
OBJECTIVE: To evaluate adherence to an agreed minimum dataset for patient medication information exchange between hospitals and general practitioners. DESIGN: Quasi pre-post design with a supplementary post-program comparison group; sequential descriptive surveys of patients following recent discharge from public hospitals; opinion questionnaire for key hospital informants; stakeholder forum to review data and Quality Use of Medicines (QUM) action plans between pre- and post-program surveys. PARTICIPANTS AND SETTING: GPs and hospitals from the South East Area Health Service, Sydney. During 2000-2001, 81/124 GPs (65%) returned 147 patient questionnaires in initial follow-up; 88/119 GPs (74%) returned 131 questionnaires in final follow-up; a supplementary group of 54/120 GPs (45%) returned 66 questionnaires; 32/45 (71%) of nominated key informants responded to the hospital survey. RESULTS: Direct notification of GPs by hospitals of their patient's admission was unchanged from the initial level of 22%. The proportion of GPs providing medication information to the hospital increased from 38% to 51% at Stage 2 (P < 0.05) and remained at 52% at Stage 3. The proportion of GPs receiving discharge summaries directly (initially 2%) increased to 26% at Stage 2 (P < 0.001) and remained at 27% at Stage 3. CONCLUSIONS: System change is slow to occur, but changes that are implemented are maintained. The stakeholder forum suggested that a specific person should be responsible for GP liaison.