Anna Kemp-Casey

Using Australian Pharmaceutical Benefits Scheme data for pharmacoepidemiological research: challenges and approaches

The Pharmaceutical Benefits Scheme (PBS) dataset provides detailed information about subsidised medicines dispensed in Australia and is increasingly used for pharmacoepidemiological research. Use of the PBS dataset provides unique opportunities for such research, but comes with its own set of challenges that must be considered and addressed. This paper outlines some issues that commonly arise when using PBS data - relating to accurate identification of medicine dispensings and how to define medicine exposure - and suggests some possible approaches for dealing with them. The paper is intended as an introductory resource for researchers.

Graduate-entry medical students: older and wiser but not less distressed

Objectives: Australia has a growing number of graduate-entry medical courses. It is known that undergraduate medical students have high levels of psychological distress; however, little is known about graduate-entry medical students. We examined whether graduate-entry medical students had higher levels of psychological distress than the same-age general population. Method: Psychological distress was assessed in 122 graduate-entry medical students in an Australian graduate-entry medical school using the 21-item Depression Anxiety and Stress Scale. Mean scores and the proportion of students with scores in the highly distressed range were compared with non-clinical population norms. Scores were also compared across demographic characteristics. Results: Medical students reported higher mean depression, anxiety and stress scores than the general population and were more likely to score in the moderate to extremely high range for anxiety (45% vs. 13%; p<0.001) and stress (17% vs. 13%; p=0.003). Anxiety and stress were higher in students aged ≥30 years than in younger students. Conclusions: Despite their maturity, graduate-entry students experienced high psychological distress. Anxiety and stress were higher, not lower, with increasing age. Our results suggest that graduate-entry medical students warrant the same level of concern as their school-leaving counterparts. Further interventions to support these students during medical school are warranted.

A record linkage study of antidepressant medication use and weight change in Australian adults.

Objective: Antidepressant use is widespread. While weight gain is a commonly reported side-effect of antidepressant use and has the potential to affect population health, there is little large-scale population-based evidence on the issue, particularly for long-term use (⩾12 months). The aim of this study is to investigate the association between antidepressant use and weight change, including whether this relationship varies according to antidepressant class, recency of use, duration of use and dose. Methods: Annual percentage weight change was calculated from self-reported weight at two time-points from 20,751 participants aged ⩾45 years from the 45 and Up Study – a population-based cohort study from New South Wales, Australia. Antidepressant use, ascertained from linked pharmaceutical data, from 19 months before baseline until end of follow-up (mean = 3.3 years of follow-up), was categorised as current, past-only, non-persistent or non-use. The association between antidepressant use and weight change was modelled using linear and multinomial logistic regressions and according to antidepressant class, recency, duration and dose. Results: Antidepressants were dispensed to 23% of participants (n = 4748) during the study period. Current antidepressant users were significantly more likely to gain >3% of their body weight annually than non-users (adjusted relative risk ratio = 1.19; 95% confidence interval: [1.03, 1.38]); the risk increased with increasing dose among current users (p[trend] = 0.003). Risk of weight gain did not vary significantly according to antidepressant class, recency or duration of use; however, statistical power was limited. No significant associations were found between antidepressant use and weight loss. Conclusion: Current antidepressant use was associated with modest but statistically significant annual gains in weight, with similar effects observed across the different classes of antidepressants used.

Medication use and potentially high-risk prescribing in older patients hospitalized for diabetes: a missed opportunity to improve care?

To examine the appropriateness of medicine use and potentially high‐risk prescribing before and after hospitalization for diabetes.

Live delivery outcome after tubal sterilization reversal: a population-based study

OBJECTIVE To determine the cumulative incidence of live delivery in women who underwent reversal of tubal sterilization. DESIGN Population-based retrospective cohort study. SETTING Hospitals in Western Australia. PATIENT(S) All women aged 20-44 years, with a history of hospital admission for tubal sterilization, who subsequently underwent reversal of sterilization during the period 1985 to 2009 in Western Australia (n = 1,898). INTERVENTION(S) Data regarding reversal of sterilization and prior tubal sterilization were extracted from routinely collected administrative hospital separation records, until commencement of IVF treatment. MAIN OUTCOME MEASURE(S) First live-delivery rates. RESULT(S) There were 969 first live deliveries observed during the study period. The overall cumulative live-delivery rate was 20% (95% confidence interval [CI] 18-23) within the first year after reversal, 40% (95% CI 38-42) at 2 years, 51% (95% CI 48-53) at 5 years, and 52% (95% CI 50-55) at 10 years. The 5-year cumulative live-delivery rate was significantly lower in women who were aged 40-44 years (26%) compared with younger women (aged 20-29, 30-34, and 35-39 years) (50%, 56%, and 51%, respectively). CONCLUSION(S) Women undergoing reversal of sterilization before they reach age 40 years have at least a 50% chance of delivering a live baby within the next 5 years. Up to that age, there is no significant difference in live deliveries. The live-delivery rate halves after the age of 40 years.

High rates of general practice attendance by former prisoners: a prospective cohort study

Objectives: To determine the rates at which people recently released from prison attend general practitioners, and to describe service users and their encounters.

Retinal detachment surgery in Western Australia (2000–2013): a whole-population study

Aims To determine the background incidence rate of retinal detachment (RD) in Western Australia (WA) between 2000 and 2013, identify sociodemographic features associated with increased risk of incident RD and examine trends in surgical repair technique. Methods A whole-population retrospective observational study of all people in WA was carried out using linked hospital inpatient records. Cases of RD were identified using a combination of International Classification of Diseases, Ninth revision, Clinical Modification (ICD-9-CM) and ICD-10-AM (Australian modification) diagnosis and procedure codes from routinely collected hospital inpatient data provided by the WA Data Linkage Branch. A Poisson regression model was used to examine the influence of age group, gender, season and year of surgery on RD incidence rates. Main outcome measures Age-standardised and sex-standardised incidence of first-eye RD and incidence rate ratio (IRR) of first-eye RD associated with age, sex and season. Counts of RD repair according to surgical technique. Results There were 4376 first-eye RD between 2000 and 2013. Age-standardised incidence ranged between 12.78 and 16.20 cases per 1 00 000 person-years. After adjusting for age, year and season, males had a higher risk than females for incident detachment (IRR 1.82, 95% CI (CI) 1.71 to 1.93), as did those aged 60–79 years (IRR 33.26, 95% CI 27.60 to 40.08) compared with those aged less than 20 years. RD repair with vitrectomy alone increased by 59% over the study period. Conclusion The incidence of first-eye RD remained stable between 2000 and 2013. The risk was higher in males and with older age.

Breast cancer recurrence following active treatment: Determining its incidence in the NSW population

OBJECTIVES It is important for consumers, clinicians and health service planners to know the risk of recurrence of primary breast cancer after initial treatment. At present, none of Australias state or territory cancer registries routinely report this information. We aimed to determine the incidence of recurrence in New South Wales (NSW) clinical practice for the period 18 months to 6 years after diagnosis of primary breast cancer. STUDY TYPE Retrospective cohort study using population-based linked health data. METHODS We identified 2416 women in the 45 and Up Study who were diagnosed with primary invasive breast cancer between 2003 and 2008 in NSW, and who had not had a recurrence 18 months after diagnosis. Unit-level hospital, pharmacy and outpatient medical claims were used to identify treatment for recurrence. Incidence of recurrence was calculated using individual person-time at risk (18 months to 6 years postdiagnosis), with follow-up censored for death or end of study period (median follow-up 3 years). Time to recurrence was calculated, and Cox proportional regression was used to identify womens baseline and active treatment characteristics that were predictive of recurrence up to 6 years postdiagnosis. RESULTS 217 women (9%) had a hospital, pharmacy or outpatient claim indicating breast cancer recurrence. Overall annual incidence of recurrence was 3.3%. Recurrence rates were significantly higher for women with node-positive (4.8% vs 2.5% annually; hazard ratio [HR] = 1.7; 95% confidence interval [95% CI] 1.3, 2.3) or hormone receptor-negative tumours (3.8% vs 3.1% annually; HR = 1.3; 95% CI 1.0, 1.7). Women with tumours >2 cm at diagnosis were more likely to experience recurrence than women with smaller/unknown tumours (4.8% vs 2.7% annually; HR = 1.5; 95% CI 1.1, 2.0). CONCLUSIONS A combination of routinely collected administrative health datasets can be used to determine recurrence rates, allowing future assessment of population-level changes over time and investigations of the real-world impact of specific treatments on outcomes.

Pricing policies for generic medicines in Australia, New Zealand, the Republic of Korea and Singapore: patent expiry and influence on atorvastatin price

Background Little is known about how the different policies available to promote use of generic medicines affect the price per unit supplied or sold. This study compares the influence of pricing policies for generic medicines on atorvastatin prices in Australia, New Zealand, the Republic of Korea and Singapore, after market entry of generic atorvastatin. Methods The annual price of atorvastatin per defined daily dose supplied (price/DDD) was examined for each country from 2006 to 2015 (≥2 years before and ≥4 years after generic market entry). Prices were converted to international dollars and cumulative percentage price reductions were calculated for the first 4 years following generic entry. Results Prior to market entry of generic atorvastatin, New Zealand had the lowest price (

Tobacco policy reform and population-wide antismoking activities in Australia: the impact on smoking during pregnancy

0.10/DDD), and the Republic of Korea the highest (