C. D'Arcy J. Holman

Population‐based linkage of health records in Western Australia: development of a health services research linked database

Objectives: To Introduce the Western Australian Health Services Research Linked Database as infrastructure to support aetlologic, utilisation and outcomes research. To compare the study population, data resources, technical systems and organisational supports with international best practice in record linkage and health research.

A decade of data linkage in Western Australia: strategic design, applications and benefits of the WA data linkage system

OBJECTIVES The report describes the strategic design, steps to full implementation and outcomes achieved by the Western Australian Data Linkage System (WADLS), instigated in 1995 to link up to 40 years of data from over 30 collections for an historical population of 3.7 million. Staged development has seen its expansion, initially from a linkage key to local health data sets, to encompass links to national and local health and welfare data sets, genealogical links and spatial references for mapping applications. APPLICATIONS The WADLS has supported over 400 studies with over 250 journal publications and 35 graduate research degrees. Applications have occurred in health services utilisation and outcomes, aetiologic research, disease surveillance and needs analysis, and in methodologic research. BENEFITS Longitudinal studies have become cheaper and more complete; deletion of duplicate records and correction of data artifacts have enhanced the quality of information assets; data linkage has conserved patient privacy; community machinery necessary for organised responses to health and social problems has been exercised; and the commercial return on research infrastructure investment has exceeded 1000%. Most importantly, there have been unbiased contributions to medical knowledge and identifiable advances in population health arising from the research.

Preventing Falls in Older People: Impact of an Intervention to Reduce Environmental Hazards in the Home

OBJECTIVES: To evaluate the impact of an intervention to reduce fall hazards in the homes of older people.

Long term relative survival after surgery for abdominal aortic aneurysm in Western Australia: population based study

Abstract Objective: To determine the long term relative survival of all patients who had surgery for abdominal aortic aneurysm in Western Australia during 1985-94. Design:Population based study. Setting:Western Australia. Subjects: All patients who had had surgery for abdominal aortic aneurysm in Western Australia during 1985-94. Main outcome measures: Morbidity and mortality data of patients admitted and surgically treated for abdominal aortic aneurysm in Western Australia during 1985-94. Elective, ruptured, and acute non-ruptured cases were analysed separately. Independent analyses for sex and patients aged 80 years or more were also undertaken. Postoperative (>30 days) relative survival was assessed against age and sex matched controls. Results: Overall, 1475 (1257 men, 218 women) cases were identified. The crude five year survival after elective surgery, including deaths within 30 days of surgery, was 79% for both men and women. When compared with a matched population the five year relative survival after elective surgery was 94.9% (95% confidence interval 89.9% to 99.9%) for men but only 88.0% (76.3% to 99.7%) for women. The five year relative survival of those aged 80 years and over was good: 116.6% (89.1% to 144.0%) compared with 92.4% (87.7% to 97.0%) for those under 80 years of age (men and women combined). Cardiovascular disease caused 57.8% of the 341 deaths after 30 days. Conclusion: In a condition such as abdominal aortic aneurysm, which occurs in elderly patients, relative survival is more clinically meaningful than crude survival. The five year relative survival in cases of elective and ruptured abdominal aortic aneurysm was better in men than in women. This is probably because of greater comorbidity in women with abdominal aortic aneurysm and this deserves more attention in the future. The long term survival outcome in octogenarians supports surgery in selected cases.

Preventing Falls in Older People: Outcome Evaluation of a Randomized Controlled Trial

OBJECTIVES: To evaluate the outcome of an intervention to reduce hazards in the home on the rate of falls in seniors.

Prostate cancer: socio-economic, geographical and private-health insurance effects on care and survival.

To examine the effects of demographic, geographical and socio‐economic factors, and the influence of private health insurance, on patterns of prostate cancer care and 3‐year survival in Western Australia (WA).

A randomized controlled equivalence trial of short‐term complications and efficacy of tension‐free vaginal tape and suprapubic urethral support sling for treating stress incontinence

To establish the equivalence between the tension‐free vaginal tape (TVT) and the suprapubic urethral support sling (SPARC). Approximately 35% of women have stress urinary incontinence (SUI), and although TVT is now perceived as the standard treatment, the SPARC is a very similar procedure and is thought to have fewer peri‐operative complications.

Outcomes of out-of-hospital cardiac arrest patients in Perth, Western Australia, 1996-1999

STUDY OBJECTIVE To describe the epidemiology and survival from out-of-hospital cardiac arrest. DESIGN Longitudinal follow-up study from the time of paramedic attendance to 12 months later. SETTING Perth, Western Australia (WA), a metropolitan capital city with an adult population of approximately one million people. METHOD The St John Ambulance Australia (WA Ambulance Service Incorporated) cardiac arrest database was linked to the WA hospital morbidity and mortality data using probabilistic matching. INCIDENCE Of 3730 cardiorespiratory arrests in 1996-1999, the age standardised rate of arrests of presumed cardiac origin, where resuscitation was attempted (n=1293) was 32.9 per 100000 person-years and 7.1 per 100000 person-years for bystander-witnessed VF/VT arrests. SURVIVAL Survival to 28 days was 6.8% following all bystander-witnessed cardiac arrests; 10.6% following bystander-witnessed VF/VT arrests and 33% for paramedic-witnessed cardiac arrests. Logistic regression analysis showed an inverse association between ambulance response time interval and survival following all bystander-witnessed cardiac arrests (and VF/VT arrests). ONE YEAR SURVIVAL: 89% of bystander-witnessed cardiac arrest survivors and 92% of paramedic-witnessed cardiac arrests were still alive at 1 year post-arrest. CONCLUSION The trends in occurrence and survival following out-of-hospital cardiac arrest in Perth, WA, are similar to those found elsewhere. There is an opportunity to strengthen the chain of survival by reducing the response time interval and increasing the use of bystander cardiopulmonary resuscitation (CPR). First-responder programs and public access defibrillation will need to be considered in the light of local demographics, location and the epidemiologic features of out-of-hospital cardiac arrest.

Dietary intakes of mushrooms and green tea combine to reduce the risk of breast cancer in chinese women

To investigate effects of dietary mushrooms and joint effects of mushrooms and green tea on breast cancer, a case–control study was conducted in southeast China in 2004–2005. The incident cases were 1,009 female patients aged 20–87 years with histologically confirmed breast cancer. The 1,009 age‐matched controls were healthy women randomly recruited from outpatient breast clinics. Information on frequency and quantity of dietary intake of mushrooms and tea consumption, usual diet, and lifestyle were collected by face‐to‐face interview using a validated and reliable questionnaire. Compared with nonconsumers, the Odds ratios (Ors) were 0.36 (95% CI = 0.25–0.51) and 0.53 (0.38–0.73) for daily intake of ≥10 g fresh mushrooms and ≥4 g dried mushrooms, based on multivariate logistic regression analysis adjusting for established and potential confounders. There were dose–response relationships with significant tests for trend (p < 0.001). The inverse association was found in both pre‐ and postmenopausal women. Compared with those who consumed neither mushrooms nor green tea, the ORs were 0.11 (0.06–0.20) and 0.18 (0.11–0.29) for daily high intake of fresh and dried mushrooms combined with consuming beverages made from ≥1.05 g dried green tea leaves per day. The corresponding linear trends were statistically significant for joint effect (p < 0.001). We conclude that higher dietary intake of mushrooms decreased breast cancer risk in pre‐ and postmenopausal Chinese women and an additional decreased risk of breast cancer from joint effect of mushrooms and green tea was observed. More research is warranted to examine the effects of dietary mushrooms and mechanism of joint effects of phytochemicals on breast cancer.

Public good through data linkage: measuring research outputs from the Western Australian Data Linkage System

Objective: To measure the ‘public good’ by retrieving, collating, reviewing and assessing outputs from projects using information supplied from the Western Australian Data Linkage System (WADLS) during 1995‐2003.