Concessional Beneficiaries Research Articles

Utilisation of teratogenic medicines before and during pregnancy in Australian women.

Given the potential hazards of teratogenic medicines, to a fetus exposed in utero, monitoring their use around pregnancy is imperative. To measure utilisation of teratogenic medicines (Therapeutic Goods Administration's category D or X) in women who gave birth in New South Wales, Australia, during pregnancy and the 24months prior. We used linked population-based datasets including dispensing and perinatal data for all deliveries in NSW between 2005 and 2012. We included pregnancies among concessional beneficiaries only, with complete ascertainment of dispensing claims. Pre-pregnancy and during-pregnancy periods were based on birth dates and gestational age. We determined prevalence of exposure using percent of pregnancies in which women had at least one dispensed teratogenic medicine in three-month time periods. The study included 191588 pregnancies (145419 women). Prevalence of exposure to D/X medicines anytime during pregnancy was 2.0% (<20 pregnancies category X), decreasing from pre-pregnancy (3.8-6.0%) to first trimester (1.5%), further decreasing in second and third trimesters (0.8% and 0.6% respectively). We observed large reductions in antibiotic prevalence but only modest reductions for psychotropics and antilipidemic agents (all category D). Our results suggest higher use of potentially teratogenic medicines (category D) than those strictly contraindicated for use (category X), during pregnancy. Overall, use was higher in the first trimester than the rest of pregnancy. The high prevalence of potentially contraindicated psychotropics in all three trimesters may suggest a higher benefit-to-risk ratio and warrants future research focusing on the reasons for their prescribing to pregnant women.

Polypharmacy among older Australians, 2006-2017: a population-based study.

To estimate the prevalence of polypharmacy among Australians aged 70 years or more, 2006-2017. Analysis of a random 10% sample of Pharmaceutical Benefits Scheme (PBS) data for people aged 70 or more who were dispensed PBS-listed medicines between 1 January 2006 and 31 December 2017. Prevalence of continuous polypharmacy (five or more unique medicines dispensed during both 1 April - 30 June and 1 October - 31 December in a calendar year) among older Australians, and the estimated number of people affected in 2017; changes in prevalence of continuous polypharmacy among older concessional beneficiaries, 2006-2017. In 2017, 36.1% of older Australians were affected by continuous polypharmacy, or an estimated 935240 people. Rates of polypharmacy were higher among women than men (36.6% v 35.4%) and were highest among those aged 80-84 years (43.9%) or 85-89 years (46.0%). The prevalence of polypharmacy among PBS concessional beneficiaries aged 70 or more increased by 9% during 2006-2017 (from 33.2% to 36.2%), but the number of people affected increased by 52% (from 543950 to 828950). The prevalence of polypharmacy among older Australians is relatively high, affecting almost one million older people, and the number is increasing as the population ages. Our estimates are probably low, as we could not take over-the-counter or complementary medicines or private prescriptions into account. Polypharmacy can be appropriate, but there is substantial evidence for its potential harm and the importance of rationalising unnecessary medicines, particularly in older people.

Rapid and substantial increases in anticoagulant use and expenditure in Australia following the introduction of new types of oral anticoagulants.

ObjectivesTo quantify changes in anticoagulant use in Australia since the introduction of Non-vitamin K antagonist anticoagulants (NOACs) and to estimate government expenditure.DesignInterrupted-time-series analysis quantifying anticoagulant dispensing, before and after first Pharmaceutical Benefits Scheme (PBS) NOAC listing in August 2009 for venous thromboembolism prevention; and expanded listing for stroke prevention in non-valvular atrial fibrillation (AF) in August 2013, up to June 2016. Estimated government expenditure on PBS-listed anticoagulants.Setting and participantsPBS dispensing in 10% random sample of Australians, restricted to continuous concessional beneficiaries dispensed oral anticoagulants from July 2005 to June 2016. Total PBS anticoagulant expenditure was calculated using Medicare Australia statistics.Main outcome measuresMonthly dispensing and initiation of oral anticoagulants (warfarin, rivaroxaban, dabigatran or apixaban). Annual PBS anticoagulant expenditure.ResultsAn estimated 149,180 concessional beneficiaries were dispensed anticoagulants (100% warfarin) during July 2005. This increased to 292,550 during June 2016, of whom 47.0%, 27.1%, 18.7% and 7.2% were dispensed warfarin, rivaroxaban, apixaban and dabigatran, respectively. Of 16,500 initiated on anticoagulants in June 2016, 24.3%, 38.2%, 30.0% and 7.5% were initiated on warfarin, rivaroxaban, apixaban, and dabigatran, respectively. Compared to July 2005-July 2013, from August 2013-June 2016, dispensings for all anticoagulants increased by 2,303 dispensings/month (p<0.001, 95%CI = [1,229 3,376]); warfarin dispensing decreased by 1,803 dispensings/month (p<0.001, 95%CI = [–2,606, –1,000]). Total PBS anticoagulant expenditure was $19.5 million (97.0% concessional) in 2008/09, of which 100% was warfarin and $203.3 million (86.2% concessional) in 2015/16, of which 11.2% was warfarin.ConclusionsThe introduction of the NOACs led to substantial increases in anticoagulant use and expenditure in Australia.

Predictors of first-year nonadherence and discontinuation of statins among older adults: a retrospective cohort study.

The aim of this study was to examine the level of and predictors of statin nonadherence and discontinuation among older adults. Among 22 340 Australians aged ≥65 years who initiated statin therapy from January 2014 to December 2015, we estimated the first-year nonadherence (proportion of days covered [PDC] <0.80) and discontinuation (≥90 days without statin coverage) rates. Predictors of nonadherence and discontinuation were examined via multivariable logistic regression. Analyses were performed separately for general beneficiaries (with a higher co-payment; n=4841) and concessional beneficiaries (with a lower co-payment; n=17 499). During the one-year follow-up, 55.1% were nonadherent (concessional 52.6%; general beneficiaries 64.2%) and 44.7% discontinued statins (concessional 43.1%; general beneficiaries 50.4%). Among concessional beneficiaries, those aged 75-84 years and ≥85 years were more likely to discontinue than people aged 65-74 years (odds ratio 1.11, 95% confidence interval 1.04-1.19 and 1.38, 1.23-1.54, respectively). Diabetes was associated with an increased likelihood of nonadherence and discontinuation, while hypertension, angina and congestive heart failure were associated with a lower likelihood of nonadherence and discontinuation. Anxiety was associated with an increased likelihood of discontinuation, but polypharmacy (concurrent use of five or more drugs) was associated with a lower likelihood of nonadherence and discontinuation. Statin initiation by a general medical practitioner was associated with both increased likelihood of nonadherence and discontinuation. Similar predictors of nonadherence and discontinuation were identified for the general beneficiaries. Among older adults prescribed statins, first-year nonadherence and discontinuation are high. Specific population subgroups such as people aged ≥85 years, those with diabetes or anxiety may require additional attention to improve statin adherence.

A population-based study of transdermal fentanyl initiation in Australian clinical practice.

Although guidelines caution against initiation of transdermal (TD) fentanyl among those who are opioid naïve, there is concern that not all people receive adequate prior opioid exposure. This study examined the percentage of people who are opioid naïve at the time of TD fentanyl initiation in Australia; strengths initiated; and characteristics associated with being opioid naïve. This is a national retrospective cohort study derived from a 10% sample of Pharmaceutical Benefits Scheme concessional beneficiaries initiating TD fentanyl between 29 September 2009-31 December 2013. Individuals were deemed opioid naïve if they had no opioid dispensings in the previous 90days. Logistic regression was used to determine characteristics associated with being opioid naïve, including socio-demographics, likely comorbidities and previous analgesic use. A total of 13,166 people initiated TD fentanyl; 60.4% were female and 76.2% were aged ≥ 65years. Three in ten (30.4%) were opioid naïve and 63.2% initiated the 12mcg/h patch. Those who were opioid naïve were more likely to be female (adjusted odds ratio (aOR) 1.35; 95% CI 1.25-1.46), older (aOR 1.85; 95% CI 1.54-2.28 for those ≥ 85years) and previously dispensed medicines for dementia (aOR 1.37; 95% CI 1.04-1.80). People previously dispensed medicines for cancer were less likely to be opioid naïve (aOR 0.57; 95% CI 0.48-0.67). Three in ten Australians initiating TD fentanyl are opioid naïve. Our findings suggest that specific patient sub-populations already at increased risk of opioid-related adverse events are not receiving prior opioid treatment before initiation, highlighting the need for greater adherence to current treatment guidelines.

Predictors of statin use among older adults: A nationwide cross-sectional study

Statins comprise a key strategy for the prevention and treatment of arteriosclerotic cardiovascular disease, but prescribing remains suboptimal. The objective of this study was to characterize the predictors of statin use among adults aged ≥65years. A cross-sectional study using Pharmaceutical Benefits Scheme (PBS) data on reimbursed prescriptions for a 10% random sample of the Australian population in 2016 was performed. Predictors of statin use were identified via multivariable logistic regression. Analyses were performed separately for people who were concessional beneficiaries (with a low, capped copayment) and other ("general") people. Among 351,471 (concessional=295,875 and general=55,596) older adults, 44.2% were dispensed statins (concessional=46.4% and general=32.2%). Among the concessional beneficiaries, people aged 75 to 84years were more likely to use statins (odds ratio [OR] 1.08, 95% confidence interval [CI] 1.06-1.10), whereas those aged ≥85years were less likely to use statins (OR 0.71, 95% CI 0.69-0.72), compared with people aged 65 to 74years. Men were more likely to use statins than women (OR 1.14, 95% CI 1.12-1.16). Diabetes was associated with over 2-fold (OR 2.48, 95% CI 2.43-2.53) increased likelihood of statin use. People with cardiovascular-related conditions including hypertension, angina, and congestive heart failure experienced increased likelihood of statin use as was being dispensed anticoagulant or antiplatelet medication. Having malignancy, psychotic illness, or pain were associated with lower likelihood of statin use. Similar predictors of statin use were noted for the general population. More than 40% of older adults in Australia used statins in 2016 with uptake dependent on individual-level factors such as demographics and comorbidities. Future research should examine the extent to which provider and/or health system-level factors contribute to the variable uptake of statin therapy.

Psychotropic medication use in Australia, 2007 to 2015: Changes in annual incidence, prevalence and treatment exposure

To examine changes in annual patterns of psychotropic medication use in Australia from 2007 to 2015. We used a 10% sample of individual-level nationwide dispensing claims for concessional beneficiaries dispensed psychotropic medications (stratified by class, subclass) to investigate annual trends and changes in the incidence and prevalence of use, median annual duration of exposure, proportion of people with single psychotropic dispensing and median defined daily doses per person dispensed each medicine per year. Over the study period, there was a 26.1% decrease in the incidence and a 2.6% increase in the prevalence of all psychotropic medicine use. We observed a decrease in the annual incidence and prevalence of antidepressants (11.6% and 16.8%, respectively) but increases in the median annual duration of exposure (7.4%). Amitriptyline had the highest proportion of single dispensings of all antidepressants throughout the study period (26.5% in 2015) and defined daily doses per person dispensed each medicine per year increased by 20% for antidepressants overall. Benzodiazepine use decreased across all measures over the study period apart from long-term use (exposure for >240 days of the year), which in 2015 was 23.6% of those dispensed a benzodiazepine. We observed a relative increase in the incidence and prevalence of antipsychotic use (14.2% and 26.8%, respectively), and haloperidol had the highest proportion of single dispensings of any antipsychotic throughout the study period (47.5% in 2015). We observed a relative increase in the incidence and prevalence of attention-deficit hyperactivity disorder medication use of 114.0% and 101.8%, respectively, over the study period. Increasing doses and treatment durations of antidepressants warrants further investigation due to concerns about overuse. Single dispensings of amitriptyline and haloperidol may indicate off-label use and long-term use of benzodiazepines remains problematic. Despite increases in attention-deficit hyperactivity disorder medication use, prevalence of use is still much lower than the estimated prevalence of attention-deficit hyperactivity disorder in the adult population.

Prescribing patterns of analgesics and other medicines by dental practitioners in Australia from 2001 to 2012.

Dental practitioners are able to prescribe a variety of medicines subsidized on the Pharmaceutical Benefits Schedule (PBS), the main categories of which are analgesics and antibiotics. We aimed to investigate the patterns of PBS prescribing of non-antimicrobial medicines by dental practitioners in Australia from 2001 to 2012. Data were collected from Medicare Australia on prescriptions from dental practitioners dispensed to concessional beneficiaries between 2001 and 2012. We examined patterns of use over time. There was an overall increase in number of prescriptions and in dispensed use (standardized by dose and population) of analgesic medicines for the concessional population over the 12-years period. The use of dentally prescribed analgesics increased 15%, with use of nonsteroidal anti-inflammatory drugs increasing by 41% and opioid analgesics by 12%. Prescribing of the oxycodone 5-mg tablet increased 344% between 2005 and 2012, and dental prescription of the benzodiazepines diazepam and temazepam increased by 51% and 229%, respectively, over the observation period. Injectable corticosteroid use increased by 19%. Conversely, use of carbamazepine and anti-emetics decreased by 39% and 10%, respectively. Dental prescribing of analgesics, anti-inflammatories and benzodiazepines in the concessional population has increased significantly over the past decade. These data can form the baseline to further examine appropriate medicine use in the management of dental conditions.

Triptan use in Australia 1997-2015: A pharmacoepidemiological study

This study examined the use of triptan derivatives in Australia between 1997 and 2015, based on a national drug reimbursement database, and compared patterns of use with available international data. We obtained publically available data on the number of prescriptions for triptans marketed in Australia (sumatriptan, eletriptan, rizatriptan, zolmitriptan, naratriptan). Dispensed use was measured as defined daily dose (DDD per 1000 population per day) for Australia's concessional beneficiaries (low-income earners, people with disabilities, and seniors). Total triptan use increased at an average annual rate of 112% over the 18-year period. Sumatriptan was the preferred triptan throughout (average annual increase 45%). Zolmitriptan and naratriptan use peaked in 2004, then decreased. Rizatriptan and eletriptan became available in 2010. There were 3.2-fold and 5.9-fold annual increases in their use from 2011 to 2105. There was some evidence suggesting that pattern of triptan use in concessional beneficiaries probably reflected pattern of overall triptan use in Australia. The use of triptan derivatives in Australia per head of population for treating migraine attacks continued to increase over the 18-year period studied, with use of recently introduced derivatives more than substituting for decreased use of older triptans. This suggests that the available treatments of migraine attacks had achieved what were considered less than adequate therapeutic outcomes.

Prescribing patterns of dental practitioners in Australia from 2001 to 2012. Antimicrobials.

The development of antibiotic resistance by bacteria is of global concern. Inappropriate prescribing has the potential to exacerbate this issue. We aimed to examine the patterns of prescribing of antimicrobial medicines by dental practitioners in Australia from 2001 to 2012. Data were collected from Medicare Australia on prescriptions from dental practitioners dispensed to concessional beneficiaries between 2001 and 2012. We examined patterns of use over time. There was an overall increase in number of prescriptions and in dispensed use (standardized by dose and population) of antibiotics and antifungals for the concessional population over the 12-year period. The use of dentally prescribed antibiotics increased 50%. Amoxicillin was the most commonly prescribed antibiotic accounting for 66% of all prescriptions in 2012. Generally, there was preferential prescribing of the highest dose formulations. The use of the two antifungals increased 30% over the study period with a preference for amphotericin B (74%) rather than nystatin. These data show a concerning increase in prescribing of antibiotics and antifungals by dentists in Australia. It would appear that Australian dentists may not be prescribing these medicines appropriately; however, further research is needed to understand prescribing behaviours and decision-making by dentists.

The crux of the matter: Did the ABC's Catalyst program change statin use in Australia?

To examine the impact of a two-part special edition of the Australian Broadcasting Corporation's science journalism program Catalyst (titled Heart of the matter), aired in October 2013, that was critical of HMG-CoA reductase inhibitors ("statins"). Population-based interrupted time-series analysis of a 10% sample of Australian long-term concessional beneficiaries who were dispensed statins under the Pharmaceutical Benefits Scheme (about 51% of all people who were dispensed a statin between 1 July 2009 and 30 June 2014); dispensing of proton pump inhibitors (PPIs) was used as a comparator. Change in weekly dispensings and discontinuation of use of statins and PPIs, adjusting for seasonal and long-term trends, overall and (for statins only) stratified by the use of cardiovascular and diabetes medicines. In our sample, 191 833 people were dispensed an average of 26 946 statins weekly. Following the Catalyst program, there was a 2.60% (95% CI, 1.40%-3.77%; P < 0.001) reduction in statin dispensing, equivalent to 14 005 fewer dispensings Australia-wide every week. Dispensing decreased by 6.03% (95% CI, 3.73%-8.28%; P < 0.001) for people not dispensed other cardiovascular and diabetes medicines and 1.94% (0.42%-3.45%; P = 0.01) for those dispensed diabetes medicines. In the week the Catalyst program aired, there was a 28.8% (95% CI, 15.4%-43.7%; P < 0.001) increase in discontinuation of statin use, which decayed by 9% per week. An estimated 28 784 additional Australians ceased statin treatment. Discontinuation occurred regardless of the use of other cardiovascular and diabetes medicines. There were no significant changes in PPI use after the Catalyst program. Following airing of the Catalyst program, there was a temporary increase in discontinuation and a sustained decrease in overall statin dispensing. Up until 30 June 2014, there were 504 180 fewer dispensings of statins, and we estimate this to have affected 60 897 people.

Do pharmaceutical claims accurately reflect oncology prescribing practice? Evidence from an Australian HER2+ early breast cancer cohort (HER2EBC).

100 Background: Pharmaceutical claims are used increasingly to investigate the real-world use and impact of prescribed medicines. Claims databases are established for payment purposes, lack clinical data and only capture prescriptions for which insurers pay a contribution. We compare Pharmaceutical Benefits Scheme (PBS) dispensing claims of HER2EBC patients, with prescriptions written in oncology clinics to determine the accuracy of dispensing data to identify treatment protocols and estimate treatment cycles and durations of therapy. Methods: Our cohort comprised 110 female HER2EBC patients commencing treatment at 4 Sydney cancer centres between 2008 and 2011. Patients consented to medical chart audit and linkage to PBS claims. We constructed protocols from prescribing and dispensing records independently, based on the timing of trastuzumab and cytotoxic treatments; estimated the median number of treatment cycles and duration of therapy by protocol; and compared prescription and dispensing data. Results: Patients’ median age was 53 years (range 21.1-86.2). Based on prescribing data, 67 patients received anthracycline-containing protocols, 43 received taxane only protocols. ACTH and TCH accounted for 90% of all protocols. 75 patients (68.2%) were assigned the same protocols based on prescribing and claims data; 26 did not match as cyclophosphamide falls below the patient copayment for general PBS beneficiaries and is not captured in the claims data. Compared with prescription data, number of treatment cycles was underestimated in dispensing data (ACTH: median 30 vs 44; TCH 26 vs 29); trastuzumab-based treatment is administered weekly in ACTH but only dispensed 3-weekly. Durations of therapy differed by ≤5% in dispensing versus prescription data (ACTH 422 days vs 466; TCH 368 vs 367). Conclusions: PBS dispensing data is reliable for establishing treatment protocols in concessional beneficiaries and duration of therapy in all patients. Claims data underestimates treatment cycles as administration occurs more frequently than dispensing. These limitations must be considered when undertaking population-based studies using claims data in HER2EBC.

Cost is a major barrier to the use of inhaled corticosteroids for obstructive lung disease

To examine the effect of the level of patient copayment on the rate of purchase of inhaled corticosteroids (ICS) by patients with obstructive lung disease. Cross-sectional study of records of all prescriptions for ICS dispensed to general and concessional beneficiaries aged 15 years or over in the period January 2003 to December 2006. Data were obtained from the Pharmaceutical Benefits Scheme, which subsidises medication costs for all Australians. The number of prescriptions for ICS dispensed to government concession card holders compared with the number dispensed to general beneficiaries, expressed as a rate ratio. ICS prescriptions were dispensed to over 1.6 million people during the study period. Concession card holders were dispensed ICS prescriptions at a higher rate than general beneficiaries, both overall (43.7 v 9.1 ICS prescriptions per 100 person-years) and in all population subgroups. After adjusting for age, sex, remoteness category and socioeconomic status, people holding a concession card were dispensed over 2.5 times the number of ICS prescriptions (alone or in combination with a long-acting beta(2)-agonist) compared with general beneficiaries. Similar patterns were seen after adjusting for differences between the two groups in the prevalence of obstructive lung disease. As the patient copayment for general beneficiaries is over six times higher than for concession card holders, our findings imply that cost is a barrier to the purchase of ICS prescriptions for obstructive lung disease, independent of socioeconomic status.

Increased patient co‐payments and changes in PBS‐subsidised prescription medicines dispensed in Western Australia

To determine whether a 24% increase in patient co-payments in January 2005 and two related co-payment changes for medicines subsidised under the Australian Pharmaceutical Benefits Scheme (PBS) were associated with changes in dispensings in Western Australia (WA). We analysed aggregate monthly prescription counts and defined daily dose per 1,000 population per day (DDD/1,000/day) for atypical antipsychotics, combination asthma medicines, HmgCoA reductase inhibitors (statins) and proton-pump inhibitors (PPIs). Trends pre and post the co-payment increase in January 2005 were compared. In three of the four categories examined, prescription counts were significantly lower following the increase in co-payment thresholds. Compared with dispensings prior to the co-payment increase, prescriptions fell by 8% for combination asthma medicines (p<0.001), 9% for PPIs (p<0.001) and 5% for statins (p<0.001). Following the rise in co-payments, DDD/1,000/day decreased for all four categories. Decreases in dispensings to concessional beneficiaries were between 4% and 5% larger than for general beneficiary patients. The reduction in the both prescription counts and DDD/1,000/day observed for combination asthma medicines, PPIs and statins, which all remained above co-payment thresholds, suggests the increase in PBS co-payments has affected utilisation of these subsidised medicines. The results indicate that increases in patient contributions particularly impact on concessional patients' ability to afford prescription medicines.