Estimates of drug treated diabetes incidence and prevalence using Australian administrative pharmaceutical data.

INTRODUCTION: The incidence and prevalence of diabetes within a population are important public health metrics. Pharmaceutical administrative data may offer a resource that can contribute to quantifying these measures using the recorded signals derived from the drugs used to treat people with diabetes. OBJECTIVE: To estimate the longitudinal incidence and prevalence of drug treated (DT) diabetes in Australia utilising an Australian Pharmaceutical Benefits Scheme (PBS) dataset and compare estimates with community survey data for all diabetes reported in the Australian National Health Survey (NHS). METHODS: Persons with DT diabetes were identified within the PBS dataset using assigned Anatomic Therapeutic Chemical codes for 'Drugs used in diabetes'. Prevalent persons with DT diabetes were determined by a single annual treatment, and incident cases from the earliest treatment with diabetes medications. Counts were aggregated by age group and utilised Australian national census data as a denominator to calculate diabetes disease frequencies for the period 2004-14. Comparison of PBS prevalence data was made with NHS surveys over equivalent years. RESULTS: The age adjusted incidence of DT diabetes was 3.4/1000 in 2006 and increased to 3.8/1000 in 2011 and 5.1/1000 in 2014. Age adjusted prevalence of DT diabetes in Australia also rose from 26.7/1000 in 2006 to 32.1/1000 in 2011 and 42.1/1000 in 2014. DT diabetes prevalence estimates correlated with NHS estimates of self-reported diabetes prevalence across age groups and in 2014 was r = 0.987. However, PBS estimates of DT diabetes prevalence generally underestimated NHS values of self-reported diabetes in older age groups with mean percentage differences of -22% to -3%. In contrast, PBS data captured more younger persons with diabetes in comparison to NHS data. These differences were then used to adjust DT diabetes incidence rates to provide age specific estimates that could potentially reflect diabetes incidence estimates acquired by community survey. CONCLUSIONS: PBS data representing dispensed medications prescribed to persons with diabetes offers a perspective for the assessment of diabetes incidence and prevalence. PBS derived DT diabetes prevalence estimates correlate well with community survey estimates of self-reported diabetes, but underestimate NHS data in older age groups. Calibrated DT incidence estimates may potentially reflect community survey derived diabetes incidence estimates and may offer a method for longitudinal monitoring.

Estimates of age specific death rates in people with diabetes and associated multimorbidity using Australian administrative pharmaceutical data.

INTRODUCTION: Estimating the mortality risk of persons with diabetes can be challenging. Associated conditions such as cardiovascular disease can become the primary cause of mortality and the underlying contribution of diabetes not recorded. Alternative methods to assess mortality risk in people with diabetes would be useful. OBJECTIVE: To evaluate an Australian pharmaceutical database to identify multi-morbidity cohorts associated with diabetes and determine mortality rates in these groups using prescription exchange cessation as a proxy event for death. METHODS: Australian Pharmaceutical Benefits Scheme data covering the period 2003-14 were used. Persons with diabetes, cardiovascular diseases and dyslipidemia were identified using Anatomic Therapeutic Chemical codes allocated to their recorded dispensed treatments. People with combinations of these conditions were followed and the last recorded prescription exchange used as a proxy event for mortality. Age and gender specific mortality rates and mortality rate ratios for the multi-morbidity cohorts were then calculated from the number of deaths occurring within 10 years. RESULTS: 346,201 individuals were identified as taking treatments for diabetes, dyslipidemia and cardiovascular conditions in 2004, 86,165 deaths occurred within 10 years of follow up. Overall crude mortality was 26.2/1,000 person years. Age specific mortality rates and rate ratios were calculated for various multi-morbidity groupings. Statin treatments improved the mortality rates associated with diabetes and cardiovascular disease in persons age >54 (Log-Rank <.001). CONCLUSIONS: Administrative pharmaceutical data can be used to identify persons with diabetes and associated multi-morbidities. Proxy mortality events defined by the cessation of treatment can generate mortality rates, providing an alternative perspective for the assessment of mortality risk.

Long-term survival following successful abdominal aortic aneurysm repair evaluated using Australian administrative data.

BACKGROUND: Long-term survival (LTS) following abdominal aortic aneurysm (AAA) surgery is an outcome that can compare open surgical repair (OSR) and endovascular AAA repair (EVAR) methods. We examined the LTS of persons following successful AAA repair using administrative health data covering the Australian Pharmaceutical Benefits and Medicare Benefits Schemes from 1993 to 2014. METHODS: Participants undergoing AAA surgery were identified using procedure codes and the last service provision date used as a proxy mortality marker. LTS and relative survival with control populations in those who survived the initial post-operative period were used to compare OSR and EVAR and estimates between the first and second halves of the study. RESULTS: A total of 2060 persons who had undergone AAA repair were identified. Overall median LTS (95% CI) following elective, ruptured OSR and EVAR were 10.4 (9.1-11.0), 8.5 (6.7-10.3) and 9.7 (8.1-11.3) years, respectively. Relative survival rates at 5 and 10 years were 0.89 and 0.7 for OSR and 0.87 and 0.66 for EVAR. LTS rates were similar for OSR and EVAR in age groups 65-84 years (EVAR/OSR range 0.96-1.16); however, EVAR was superior to OSR in persons aged >85 years at 5 years (EVAR/OSR 1.32, log-rank P < 0.05). Relative survival following all techniques of AAA repair showed no significant change over the duration of the study. CONCLUSION: LTS following AAA repair was heterogeneous in comparison with control populations and varied with age and procedure. The 5-year LTS following EVAR in persons aged >85 years is superior to OSR. Administrative data can define long-term outcomes following aortic aneurysm surgery and may complement data already collected by surgeons.

Cervical re-explorations and proxy survival following parathyroidectomy for primary hyperparathyroidism using Australian administrative data.

BACKGROUND: Administrative data may have utility in the impartial assessment of surgical outcomes and rare events. We have used a publicly available sample of the Australian pharmaceutical and health service provision (medical benefits scheme) databases to assess outcomes following parathyroidectomy for primary hyperparathyroidism (PHP). METHODS: A cohort study using linked pharmaceutical and medical benefits schemes data was performed covering the period 1993-2014. Procedure codes identified participants undergoing parathyroidectomy for PHP and subsequent cervical re-exploration surgery (CRX), and the last service date used as a proxy for survival. Time to CRX and survival were modelled using Kaplan-Meier analysis. Demographic data and the era of parathyroid surgery were managed as covariates for Cox regression survival analyses. RESULTS: A total of 2165 persons undergoing parathyroidectomy for PHP were identified. Median follow-up was 5.3 years (range 0.2-22). The annual number of parathyroidectomies for PHP increased gradually; 72 individuals underwent CRX (3.3%). The median time to CRX was 152 days (confidence interval 0-396) in 2000-2004 reducing to 47 days (confidence interval 15-78) for the period 2010-2014 (log-rank P = 0.027). The proportion of persons requiring CRX reduced over time from 6.1% in 1997 to 2.1% in 2012 (r2 = 0.5817, P = 0.023). Overall median survival (24.6 years) was poorer when compared with age matched controls (log-rank P = 0.025) but was not associated with CRX or gender. CONCLUSION: Administrative data can be used for the assessment of surgical outcomes and may be useful for comparisons of surgical performance, and the appraisal of infrequent events. CRX rates following parathyroidectomy for PHP are improving in Australia.

A comparison of Australian chronic disease prevalence estimates using administrative pharmaceutical dispensing data with international and community survey data.

INTRODUCTION: Chronic disease (CD) is a leading cause of population mortality, illness and disability. Identification of CD using administrative data is increasingly used and may have utility in monitoring population health. Pharmaceutical administrative data using World Health Organization, Anatomic Therapeutic Chemical Codification (ATC) assigned to prescribed medicines may offer an improved method to define persons with certain CD and enable the calculation of population prevalence. OBJECTIVE: To assess the feasibility of Australian Pharmaceutical Benefits Scheme (PBS) dispensing data, to provide realistic measures of chronic disease prevalence using ATC codification, and compare values with international data using similar ATC methods and Australian community surveys. METHODS: Twenty-two chronic diseases were identified using World Health Organization (WHO) formulated ATC codes assigned to treatments received and recorded in a PBS database. Distinct treatment episodes prescribed to individuals were counted annually for prevalence estimates. Comparisons were then made with estimates from international studies using pharmaceutical data and published Australian community surveys. RESULTS: PBS prevalence estimates for a range of chronic diseases listed in European studies and Australian community surveys demonstrated good correlation. PBS estimates of the prevalence of diabetes, cardiovascular disease and hypertension, dyslipidemia, and respiratory disease with comparable Australian National Health Survey in older adults showed correlations of between (r = 0.82 - 0.99) and a range of percentage error of -11% to 59%. However, other conditions such as psychological disease and migraine showed greater disparity and correlated less well. CONCLUSIONS: Although not without limitations, Australian administrative pharmaceutical dispensing data may provide an alternative perspective on population health and a useful resource to estimate the prevalence of a number of chronic diseases within the Australian population.

Port site metastasis following diagnostic laparoscopy for a malignant Gastro-intestinal stromal tumour.

BACKGROUND: Gastro-Intestinal stromal tumours (GISTs) are rare and our understanding of their natural history and optimal treatment are continually evolving. Port site metastasis after laparoscopy for a GIST is an extremely rare phenomenon. CASE PRESENTATION: We report a case with relevant imaging and discuss factors that may have contributed to the development of this isolated metastasis. CONCLUSION: Percutaneous methods of sampling GIST tumours for analysis should be avoided if at all possible. When necessary, prophylactic measures should be utilised to minimise the risk of seeding.

Photodynamic therapy with 5,10,15,20-tetrakis(m-hydroxyphenyl) bacteriochlorin for colorectal liver metastases is safe and feasible: results from a phase I study.

BACKGROUND: The prognosis for patients with liver metastases from colorectal carcinoma is limited because of the low number of patients who are eligible for curative hepatic resection. In this phase I study, 31 liver metastases in 24 patients with nonresectable metastases from colorectal carcinoma were treated with photodynamic therapy (PDT). METHODS: The photosensitizer 5,10,15,20-tetrakis(m-hydroxyphenyl)bacteriochlorin (mTHPBC) was intravenously administered in a dose of .6 mg/kg (n = 12) or .3 mg/kg (n = 12). After 120 hours (n = 18) or 48 hours (n = 6), tumors were illuminated for 300 to 600 seconds through percutaneously inserted optical fibers with a light dose of 60 J/cm of diffuser (740 nm). RESULTS: Tumor necrosis at 1 month after PDT was achieved in all treated lesions. Laser treatment was associated with mild pain (n = 8) and transient subclinical hepatotoxicity (n = 21). In one patient, PDT damage to the pancreas was inflicted, and in another patient, PDT damage of the skin occurred, but no serious clinical complications from PDT were reported. Administration of .6 mg/kg of mTHPBC led to transient phlebitis in 10 patients, and 3 patients experienced mild skin phototoxicity after excess light exposure. CONCLUSIONS: Colorectal liver metastases that are ineligible for resection can be safely and effectively treated with interstitial mTHPBC-based PDT.