Ascertaining invasive breast cancer cases; the validity of administrative and self-reported data sources in Australia

Background: Statutory State-based cancer registries are considered the ‘gold standard’ for researchers identifying cancer cases in Australia, but research using self-report or administrative health datasets (e.g. hospital records) may not have linkage to a Cancer Registry and need to identify cases. This study investigated the validity of administrative and self-reported data compared with records in a State-wide Cancer Registry in identifying invasive breast cancer cases. Methods: Cases of invasive breast cancer recorded on the New South Wales (NSW) Cancer Registry between July 2004 and December 2008 (the study period) were identified for women in the 45 and Up Study. Registry cases were separately compared with suspected cases ascertained from: i) administrative hospital separations records; ii) outpatient medical service claims; iii) prescription medicines claims; and iv) the 45 and Up Study baseline survey. Ascertainment flags included diagnosis codes, surgeries (e.g. lumpectomy), services (e.g. radiotherapy), and medicines used for breast cancer, as well as self-reported diagnosis. Positive predictive value (PPV), sensitivity and specificity were calculated for flags within individual datasets, and for combinations of flags across multiple datasets. Results: Of 143,010 women in the 45 and Up Study, 2039 (1.4%) had an invasive breast tumour recorded on the NSW Cancer Registry during the study period. All of the breast cancer flags examined had high specificity (\u3e97.5%). Of the flags from individual datasets, hospital-derived ‘lumpectomy and diagnosis of invasive breast cancer’ and ‘(lumpectomy or mastectomy) and diagnosis of invasive breast cancer’ had the greatest PPV (89% and 88%, respectively); the later having greater sensitivity (59% and 82%, respectively). The flag with the highest sensitivity and PPV ≥ 85% was \u27diagnosis of invasive breast cancer\u27 (both 86%). Self-reported breast cancer diagnosis had a PPV of 50% and sensitivity of 85%, and breast radiotherapy had a PPV of 73% and a sensitivity of 58% compared with Cancer Registry records. The combination of flags with the greatest PPV and sensitivity was ‘(lumpectomy or mastectomy) and (diagnosis of invasive breast cancer or breast radiotherapy)’ (PPV and sensitivity 83%). Conclusions: In the absence of Cancer Registry data, administrative and self-reported data can be used to accurately identify cases of invasive breast cancer for sample identification, removing cases from a sample, or risk adjustment. Invasive breast cancer can be accurately identified using hospital-derived diagnosis alone or in combination with surgeries and breast radiotherapy

Treatment patterns for cancer in Western Australia: does being Indigenous make a difference?

Objective: To examine whether hospital patients with cancer who were identified as Indigenous were as likely to receive surgery for the cancer as non-Indigenous patients. Design, setting and patients: Epidemiological survey of all Western Australian (WA) patients who had a cancer registration in the state-based WA Record Linkage Project that mentioned cancer of the breast (1982–2000) or cancer of the lung or prostate (1982–2001). Main outcome measures: The likelihoods of receiving breast-conserving surgery or mastectomy for breast cancer, lung surgery for lung cancer, or radical or non-radical prostatectomy for prostate cancer were compared between the Indigenous and non-Indigenous populations using adjusted logistic regression analyses. Results: Indigenous people were less likely to receive surgery for their lung cancer (odds ratio [OR], 0.64; 95% CI, 0.41–0.98). Indigenous men were as likely as non- Indigenous men to receive non-radical prostatectomy (OR, 0.69; 95% CI, 0.40–1.17); only one Indigenous man out of 64 received radical prostatectomy. Indigenous women were as likely as non-Indigenous women to undergo breast-conserving surgery (OR, 0.86; 95% CI, 0.60–1.21). Conclusions: These results indicate a different pattern of surgical care for Indigenous patients in relation to lung and prostate, but not breast, cancer. Reasons for these disparities, such as treatment choice and barriers to care, require further investigation

Increase in Caesarean Deliveries after the Australian Private Health Insurance Incentive Policy Reforms

Background: The Australian Private Health Insurance Incentive (PHII) policy reforms implemented in 1997–2000 increased PHI membership in Australia by 50%. Given the higher rate of obstetric interventions in privately insured patients, the reforms may have led to an increase in surgical deliveries and deliveries with longer hospital stays. We aimed to investigate the effect of the PHII policy introduction on birth characteristics in Western Australia (WA). Methods and Findings: All 230,276 birth admissions from January 1995 to March 2004 were identified from administrative birth and hospital data-systems held by the WA Department of Health. Average quarterly birth rates after the PHII introduction were estimated and compared with expected rates had the reforms not occurred. Rate and percentage differences (including 95% confidence intervals) were estimated separately for public and private patients, by mode of delivery, and by length of stay in hospital following birth. The PHII policy introduction was associated with a 20% (221.4 to 219.3) decrease in public birth rates, a 51% (45.1 to 56.4) increase in private birth rates, a 5% (25.3 to 25.1) and 8% (28.9 to 27.9) decrease in unassisted and assisted vaginal deliveries respectively, a 5% (25.3 to 25.1) increase in caesarean sections with labour and 10% (8.0 to 11.7) increase in caesarean sections without labour. Similarly, birth rates where the infant stayed 0–3 days in hospital following birth decreased by 20% (221.5 to 218.5), but rates of births with .3 days in hospital increased by 15% (12.2 to 17.1). Conclusions: Following the PHII policy implementation in Australia, births in privately insured patients, caesarean deliveries and births with longer infant hospital stays increased. The reforms may not have been beneficial for quality obstetric care in Australia or the burden of Australian hospitals

Prescribing of psychostimulant medications for attention deficit hyperactivity disorder in children: Differences between clinical specialties

Objective: To examine differences in psychostimulant prescribing between paediatricians and child/adolescent psychiatrists for treating children with attention deficit hyperactivity disorder (ADHD) in Western Australia. Design: Using whole-population prescribing data, logistic and linear regressions were used to model the number of children (aged 2–17 years) treated with psychostimulants between August 2003 and December 2004 for ADHD and medication dose prescribed by clinical specialty, controlling for age, sex, body weight, and other medication use. Main outcome measures: Mean number of patients treated by specialty; associations between prescriber specialty and patient characteristics; associations between stimulant dose and patient characteristics and prescriber specialty. Results: 54 paediatricians and 23 child/adolescent psychiatrists prescribed stimulant medications for children with ADHD. The mean number of patients treated (per prescriber) was 159.8 (range, 1–1977) for paediatricians and 34.3 (range, 1–166) for psychiatrists. Boys were 32% more likely to be treated with stimulants by paediatricians (P = 0.002). Psychiatrists were 2.9 times (95% CI, 2.4–3.3; P \u3c 0.001) more likely than paediatricians to treat patients with multiple psychotropic medications. When controlled for all other factors, psychiatrists prescribed higher stimulant doses (4.5 mg/day greater; 95% CI, 2.0–7.0 mg/day; P \u3c 0.001) than paediatricians. Conclusion: Treatment of children with stimulant medicines for ADHD differed between clinical specialties. Paediatricians treated more patients per prescriber, a greater proportion of boys, and a younger age demographic, but relied less on combined psychotropic pharmacotherapy and prescribed lower stimulant doses than psychiatrists

The validity of prescription and other health service claims and self-report in identifying cases of invasive breast cancer in Australia

Background: Routinely-collected and self-reported health data are increasingly being used to identify health status and service use. Australian state-based cancer registries are the \u27\u27gold standard\u27\u27 for identifying breast cancer, but researchers working with other datasets (i.e., prescription claims) may need to identify cases without linkage to these registries. Objectives: To determine the validity of prescription claims for selective estrogen receptor modulators (SERM) and aromatase inhibitors (AI) , hospital procedures, claims for outpatient procedures and radiotherapy, and self- report in identifying cases of invasive breast cancer in Aus- tralia against the Cancer Registry. Methods: Invasive breast cancers recorded on the Cancer Register between 2004 and 2008 for women in the New South Wales 4 5 and Up Study were compared with cases identified by: (1) SERM and AI prescription claims and (2) outpatient procedures and radiotherapy from 2004 to 2009; (3) NSW Admitted Patients Data Collection (hospital records) between July 2004-February 2009; and self- reported diagnosis of breast cancer between 2003 and 2009 in the 45 and Up Study baseline survey. Sensitivity, specificity, positive and negative predictive values (PPV and NPV) were calculated for each dataset compared with the Cancer Registry. Results: Of 143,010 women in the 45 and Up cohort , 2,661 (1.9%) had breast cancer recorded on the registry. Sensitivity for self-report o f breast cancer diagnosis was 73.0%, with hospital records, PBS and MBS claims data being 86.4%, 65.7% and 58.0%, respectively. PPV was highest for hospital (84.0%) and MBS data (80.4%) and lower for self-report (40.9%) and PBS claims (49.4%). Specificity and NPV were \u3e99% for all comparison data- sets evaluated. Conclusions: In the absence of cancer registrations, cases of breast cancer were most accurately detected using hospital records, and to a lesser extent self-report. Prescription and outpatient claims had only moderate sensitivity and/or PPV, likely reflecting that not all patients have post-surgical pharmacological or medical treatment. However, all of the datasets accurately identified cases without breast cancer, so are suitable for researchers wishing to exclude breast cancer cases from their data

Blood morphine levels in naltrexone-exposed compared to non-naltrexone-exposed fatal heroin overdoses

The aim of this study was to investigate the association between prior exposure to naltrexone and increased risk of fatal heroin overdose using a review of toxicology reports for heroin-related fatalities between July 1997 to August 1999 for two groups: those treated with oral naltrexone and those who were not treated. Additional information for the oral naltrexone group was obtained from clinic files. Naltrexone-treated deaths were identified from the patient database at the Australian Medical Procedures Research Foundation (AMPRF), Perth, Western Australia (WA) through the Western Australian Department of Health, Data Linkage Project. Non-treated cases were identified from the database at the Forensic Science Laboratory, State Chemistry Centre (WA). We identified and investigated blood morphine concentrations following 21 fatal heroin overdoses with prior exposure to naltrexone and in 71 non-naltrexone-exposed cases over the same time period. The proportion of deaths where heroin use was a major contributing factor was little different in the non-naltrexone compared to the naltrexone-exposed group. Furthermore, in `acute opiate toxicity\u27 deaths, blood morphine levels were lower in non-naltrexone-exposed compared with naltrexone-exposed cases. Although there was a higher number of deaths designated as rapid (i.e. occurring within 20 minutes) in the naltrexone-exposed (89%) compared with the non-exposed group (72%) this was not statistically significant. Other drug use in relation to heroin-related fatalities is discussed. Findings do not support the hypothesis that prior exposure to naltrexone increases sensitivity to heroin toxicity

Ascertaining invasive breast cancer case: The validity of administrative and self-reported data sources in Australia

Background: Statutory State-based cancer registries are considered the ‘gold standard’ for researchers identifying cancer cases in Australia, but research using self-report or administrative health datasets (e.g. hospital records) may not have linkage to a Cancer Registry and need to identify cases. This study investigated the validity of administrative and self-reported data compared with records in a State-wide Cancer Registry in identifying invasive breast cancer cases. Methods: Cases of invasive breast cancer recorded on the New South Wales (NSW) Cancer Registry between July 2004 and December 2008 (the study period) were identified for women in the 45 and Up Study. Registry cases were separately compared with suspected cases ascertained from: i) administrative hospital separations records; ii) outpatient medical service claims; iii) prescription medicines claims; and iv) the 45 and Up Study baseline survey. Ascertainment flags included diagnosis codes, surgeries (e.g. lumpectomy), services (e.g. radiotherapy), and medicines used for breast cancer, as well as self-reported diagnosis. Positive predictive value (PPV), sensitivity and specificity were calculated for flags within individual datasets, and for combinations of flags across multiple datasets. Results: Of 143,010 women in the 45 and Up Study, 2039 (1.4%) had an invasive breast tumour recorded on the NSW Cancer Registry during the study period. All of the breast cancer flags examined had high specificity (\u3e97.5%). Of the flags from individual datasets, hospital-derived ‘lumpectomy and diagnosis of invasive breast cancer’ and ‘(lumpectomy or mastectomy) and diagnosis of invasive breast cancer’ had the greatest PPV (89% and 88%, respectively); the later having greater sensitivity (59% and 82%, respectively). The flag with the highest sensitivity and PPV ≥ 85% was \u27diagnosis of invasive breast cancer\u27 (both 86%). Self-reported breast cancer diagnosis had a PPV of 50% and sensitivity of 85%, and breast radiotherapy had a PPV of 73% and a sensitivity of 58% compared with Cancer Registry records. The combination of flags with the greatest PPV and sensitivity was ‘(lumpectomy or mastectomy) and (diagnosis of invasive breast cancer or breast radiotherapy)’ (PPV and sensitivity 83%). Conclusions: In the absence of Cancer Registry data, administrative and self-reported data can be used to accurately identify cases of invasive breast cancer for sample identification, removing cases from a sample, or risk adjustment. Invasive breast cancer can be accurately identified using hospital-derived diagnosis alone or in combination with surgeries and breast radiotherapy

Diagnosing cancer in the bush: A mixed-methods study of symptom appraisal and help-seeking behaviour in people with cancer from rural Western Australia

Background Previous studies have focused on the treatment received by rural cancer patients and have not examined their diagnostic pathways as reasons for poorer outcomes in rural Australia. Objectives To compare and explore symptom appraisal and help-seeking behaviour in patients with breast, lung, prostate or colorectal cancer from rural Western Australia (WA). Methods A mixed-methods study of people recently diagnosed with breast, lung, prostate or colorectal cancer from rural WA. The time from first symptom to diagnosis (i.e. total diagnostic interval, TDI) was calculated from interviews and medical records. Results Sixty-six participants were recruited (24 breast, 20 colorectal, 14 prostate and 8 lung cancer patients). There was a highly significant difference in time from symptom onset to seeking help between cancers (P = 0.006). Geometric mean symptom appraisal for colorectal cancer was significantly longer than that for breast and lung cancers [geometric mean differences: 2.58 (95% confidence interval, CI: 0.64–4.53), P = 0.01; 3.97 (1.63–6.30), P = 0.001, respectively]. There was a significant overall difference in arithmetic mean TDI (P = 0.046); breast cancer TDI was significantly shorter than colorectal or prostate cancer TDI [mean difference : 266.3 days (95% CI: 45.9–486.8), P = 0.019; 277.0 days, (32.1–521.9), P = 0.027, respectively]. These differences were explained by the nature and personal interpretation of symptoms, perceived as well as real problems of access to health care, optimism, stoicism, machismo, fear, embarrassment and competing demands. Conclusions Longer symptom appraisal was observed for colorectal cancer. Participants defined core characteristics of rural Australians as optimism, stoicism and machismo. These features, as well as access to health care, contribute to later presentation of cancer