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Biomedical subjects

C D Holman

Publications and source records attributed to C D Holman.

At least 37 records · Page 2Linked to original sources
PubMed2000

Differential effects on socioeconomic groups of modelling the location of mammography screening clinics using Geographic Information Systems.

OBJECTIVE: To evaluate spatial access to mammography clinics and to investigate whether relocating clinics can improve global access. To determine whether any change in access is distributed equitably between different social groups. METHODS: The study was undertaken in Perth, Western Australia in 1996. It was an analysis of travel distances to mammography clinics, comparing distances to the pattern of existing clinics and modelled relocated clinics. The study population was the 151,162 women aged 40-64 years resident in Perth in 1991. RESULTS: Overall travel distances to the existing clinics was reduced by 14% when a GIS system was used to relocate them so as to minimise the travel distance for all women. The travel distance of the most disadvantaged groups fell by 2% and by 24% for the least disadvantaged group. CONCLUSIONS: GIS modelling can be used to advantage to evaluate potential locations for screening clinics that improve the access for the target population, however global analysis should be supplemented by analysis of special groups to ensure that no group is disadvantaged by the proposal. IMPLICATIONS: If new technology is not used to evaluate the placement of health services, population travel distances may be greater than necessary, with possible impacts on attendance rates.

Australia↗
PubMed2000

Effect of distance and social disadvantage on the response to invitations to attend mammography screening.

STUDY OBJECTIVES: To investigate whether public response to an invitation to attend mammography screening can be increased by strategic relocation of the clinics. METHODS: Women invited to attend mammography screening were classified by attendance, socioeconomic status, and distance from their screening clinic. A geographic information system was used to investigate whether the response could be increased by relocating clinics to facilitate access. SETTING: The metropolitan city of Perth in Western Australia with six fixed site, publicly funded, mammography screening clinics. MAIN RESULTS: Women from disadvantaged areas, not screened previously by the mammography screening programme, had a higher response to an invitation to attend screening if they lived within 3 km of their closest clinics (12%) than if they lived further away (8%). Theoretically, the response of the target population could be increased if the existing clinics were replaced by six new clinics located closer to disadvantaged areas. CONCLUSIONS: Public health planners should be aware of the use of geographic information systems to model optimum locations of health care facilities, and be willing to assess the potential target population response to those locations.

Demography↗
PubMed2000

A decision to end a periodic syphilis-screening program in the Kimberley region.

Syphilis rates in the Kimberley region of far-northern Western Australia are among the highest in the nation. In 1986, a formal program of periodic syphilis screening was established. Decreasing syphilis rates since the early 1990s prompted, in 1999, re-evaluation of the value of periodic screening. All confirmed cases of syphilis identified in the Kimberley between January 1996 and early December 1999 as a result of syphilis serology were classified by reason for the test and staged according to disease progression. During the study period, 196 cases of syphilis (117 male, 79 female) were diagnosed; 14 (7.1%) were primary, 32 (16.3%) secondary and 150 (76.5%) latent. The periodic screening program contributed only about 10 per cent of cases, whereas testing as a result of sexually transmitted disease symptoms, sexually transmitted disease contact, institutional screening and other screening contributed the remaining cases. In January 2000, the periodic syphilis-screening program was discontinued. The effect of this policy change will be closely monitored using indicators to ensure that, should the decision not to screen prove to have been misjudged, any increase in syphilis incidence is detected early and managed appropriately.

Adolescent↗
PubMed1999

The quantification of mortality resulting from the regular use of illicit opiates.

UNLABELLED: AIMS/DESIGN: Estimates of mortality associated with illicit opiate use provide useful information to those directing and monitoring local, national and international policies and programmes. Most studies investigating the association have, however, been small with imprecise estimates of increased mortality. The current study combines data from a number of international studies in a meta-analysis to estimate more precisely mortality associated with illicit opiate use. Because HIV infection among injecting drug users differs dramatically between countries and localities, we excluded studies where AIDS was a major contributor to mortality. Studies were included only where AIDS-specific mortality accounted for less than 2% of total mortality. FINDINGS: Our results show a mortality rate for people regularly using illicit opiates, which is more than 13 times greater than that observed for the general community. It is estimated that 9.4% of total mortality in Australians aged 15-39 years of age can be attributed to regular use of illicit opiates. Application of this aetiological fraction to Australian mortality data for 1992 indicate that approximately 401 male and 161 female deaths occurred as a result of opiate use. This represents some 15,429 and 6261 person-years of life lost (to age 70) for males and females, respectively. CONCLUSIONS: The mortality rate for illicit opiate users is approximately 13 times greater than for the general population. The large number of years of life lost is reflective of the relatively young population (15-39 years of age) in which opiate-related mortality occurs. Relative risk estimates can also be applied to data on the prevalence of illicit opiate use in other countries to produce locally based aetiological fractions and estimates of person-years of life lost.

Adolescent↗
PubMed1999

Mortality and prostate cancer risk in 19,598 men after surgery for benign prostatic hyperplasia.

OBJECTIVES: To examine postoperative mortality and prostate cancer risk after the first prostatectomy for benign prostatic hypertrophy over a 17-year period in a population-based cohort of men in Western Australia, using improved methods to adjust for comorbidity. PATIENTS AND METHODS: The relative survival from death and prostate cancer incidence was calculated against the background population rates. The outcomes of transurethral resection of the prostate (TURP) and open prostatectomy (OP) were compared adjusting for calendar year, age, admission type and comorbidity using Cox regression. Fractional polynomials were used to take account of nonlinearity in confounder effects. RESULTS: At 10 years, the relative survival was 116.5% in TURP patients and 123.5% after OP. Adjusting only for confounding by age, calendar year and admission type, TURP had a higher mortality rate than OP (rate ratio, RR, 1. 20; 95% confidence interval 1.08-1.34). The RR fell to 1.10 (0.99-1. 23) after adjustment for comorbidity and to 1.07 (0.95-1.19) when accounting for nonlinearity. The relative survival from the incidence of prostate cancer at 10 years was 103.7% after TURP and 104.5% after OP. The RR adjusted for age and calendar year was 1.44 (0.94-2.21) for incidence and 1.37 (0.81-2.29) for prostate cancer mortality. CONCLUSION: There is at most a small and clinically unimportant excess mortality risk from TURP; any difference could be due to a protective effect of OP on the long-term risk of prostate cancer and a lower rate of repeat prostatectomy.

Humans↗
PubMed1999

Trends in repeat prostatectomy after surgery for benign prostate disease: application of record linkage to healthcare outcomes.

OBJECTIVE: To compare the risk of repeat prostatectomy for benign prostatic hyperplasia (BPH) in a population-based cohort of 19 598 men in Western Australia treated by transurethral resection of the prostate (TURP) or open prostatectomy over a 16-year period. PATIENTS AND METHODS: The Western Australian Health Services Research Linked Database was used to extract all hospital morbidity data, death records and prostate cancer registrations for men who had prostate surgery for BPH in 1980-95. The cumulative incidence of first repeat prostatectomy calculated using the actuarial life-table and incidence-rate ratios of the first repeat prostatectomy, comparing TURP and open prostatectomy, were obtained using Cox regression. RESULTS: The cases comprised 18 464 TURPs and 1134 open prostatectomies, from which there were 1095 subsequent repeat prostatectomies. After adjustment for calendar time, age and admission type, the incidence rate of the first repeat prostatectomy was up to 2.30 times higher (95% confidence interval, 1.62-3.27) after initial TURP than for initial open prostatectomy. The absolute risks at 8 years for TURP was 6.6%, and was 3.3% for open prostatectomy. CONCLUSION: The absolute risk of a repeat prostatectomy for TURP and open prostatectomy were consistent with the best reported international experience. There was evidence that the risk in 1990-95 had declined compared with earlier periods, despite a shift towards more closed procedures. The differential risks of repeat prostatectomy should be explained to patients and considered in the development of clinical guidelines, notwithstanding the advantages of TURP over open prostatectomy in terms of surgical morbidity and cost.

Adult↗
PubMed1999

A comparison of measures of access to child health clinics and the implications for modelling the location of new clinics.

OBJECTIVE: To determine whether measurement of access to existing child health clinics, and modelled location of new clinics, was affected by the spatial definitions of the target population. METHOD: Populations requiring childhood screening services were defined as located at individual households, and at geographic and population-weighted centroids of small and large areas. Straight-line and network distances were measured and compared from these origins to varying numbers of existing clinics. The same origins were used to model sets of locations for new clinics, and access levels were again compared. RESULTS: Travel distances for 82,499 annual baby-visits to 140 existing clinics were between 136,000 km and 84,000 km, depending on origin definition. An analysis based on small area centroid data was as accurate as one based on household data. Planning solutions for new clinics located on the basis of few large areas, with populations centred at spatially defined centroids, resulted in poorer access for the population (231,000 km of travel) than one based on many small areas with populations centred at population weighted centroids (194,000 km of travel). IMPLICATIONS: Public access to health facilities will be improved if decisions about their locations are aided by the application of spatial analysis techniques based on small area definitions.

Ambulatory Care Facilities↗
PubMed1999

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 aetiologic, 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. METHOD AND RESULTS: The WA Linked Database systematically links the available administrative health data within an Australian State of 1.7 million people. It brings together, initially, six core data elements (birth records, midwives' notifications, cancer registrations, in-patient hospital morbidity, in-patient and public out-patient mental health services data and death records). It will be updated regularly and is designed, in future extensions, to include data on primary, residential and domiciliary care and health surveys. Linkage uses probabilistic matching of patient names and other identifiers. Geocodes for spatial analysis are assigned using address linkage and mapping software. By June 1997, the project had taken 2 1/2 years to develop the system and link seven million core data records from 1980 to 1995. CONCLUSIONS: The system is consistent with international benchmarks, from four centres of excellence, for the study population, core datasets, matching and geocoding, and collaborative networks. There are prospects to redress deficiencies in primary medical contact and other data resources, validation studies, tracing systems and a more supportive legal framework. IMPLICATIONS: The WA Linked Database will be used in combination with medical record audits to provide a comprehensive evaluation of health system performance.

Data Collection↗
PubMed1999

First-time hospital admissions with illicit drug problems in indigenous and non-indigenous Western Australians: an application of record linkage to public health surveillance.

OBJECTIVE: To monitor incidence rates of first-time hospital admission with an illicit drug problem in the Indigenous and non-Indigenous populations of Western Australia in 1980-95. METHOD: Some 10,533 first admissions among 16,294 total admissions mentioning any of 19 groups of illicit drug problems were identified using linked hospital separation data from the WA Health Services Research Linked Database. RESULTS: Trends in age-standardised rates showed two distinct features: a rapid acceleration in first-time admission rates commencing from about 1991; and a cross-over of the rates in Indigenous and non-Indigenous people. In 1980, the rates were 9.2 per 100,000 PY in Indigenous and 16.4 per 100,000 PY in non-Indigenous people. By 1995, the respective rates were 180.7 and 95.5 per 100,000 PY. Largest proportional increases were observed in first-time admissions mentioning amphetamine dependence or abuse, although increases were seen also in problems due to opiates, hallucinogens, cocaine and cannabis. CONCLUSION: The results are consistent with data on the rising use of injectable amphetamines and other illicit drugs, especially among Aboriginal people. IMPLICATIONS: Urgent attention is required to identify ways of reducing health problems due to illicit substance use in both Indigenous and non-Indigenous Australians.

Hospitalization↗
PubMed1999

Validation of linked administrative data on end-stage renal failure: application of record linkage to a 'clinical base population'.

OBJECTIVE: To evaluate the use of record linkage to monitor the occurrence of end-stage renal failure in Western Australia in 1980-94. METHODS: A clinical base population of 1,046 patients was identified from the Western Australian (WA) Health Services Research Linked Database. To exclude acute renal failure, patients were selected if they received in-hospital renal dialysis on more than 10 occasions over more than 28 days in 1980-94. Estimates of annual incident and prevalent cases were validated against the ANZDATA dialysis and transplant register. Reasons for discrepancy were investigated by an ad hoc linkage between the two data sources. RESULTS: The WA Linked Database counted slightly fewer incident cases (-7%) and slightly more prevalent cases (+7%) than the ANZDATA Register. The Linked Database identified 97% of cases on the ANZDATA Register, but this fell to 83% post case definition, probably due to patients receiving home-based dialysis failing to meet our case definition. ANZDATA correctly identified 90% of cases in the linked file. CONCLUSION: Trends in end-stage renal failure from 1986 to 1994, based on the Linked Database, were the same as those reported from purpose-designed disease registers. IMPLICATIONS: Linked administrative data provide a valid and efficient means to plan and evaluate many of the routine aspects of renal dialysis and transplant services.

Adult↗
PubMed1999

Suicide rates in psychiatric in-patients: an application of record linkage to mental health research.

OBJECTIVE: To study trends in the rate of suicide in psychiatric patients in Western Australia. To examine the associations of suicide with demographic and clinical factors. METHODS: A population-based cohort of 52,010 individuals whose first psychiatric admission occurred in 1980-95 was identified from the Health Services Research Linked Database. There were 471 deaths by suicide by 31 December 1995. Age standardised suicide rates per 1,000 person-years at risk were calculated. Suicide rates in the first year after a patient's first admission were also examined and a proportional hazards regression analysis was performed to examine risk factors for suicide. RESULTS: Male psychiatric patients were 3.4 times more likely to commit suicide than female patients (95% CI 2.76-4.24). Younger patients were at higher risk than older patients, and patients with extended periods of in-patient treatment were at more than double the risk of short-stay patients. Over the 16-year period, the rate of suicide in the first year after first psychiatric admission was found to increase by 3.4% a year (95% CI -0.7-7.6%). CONCLUSIONS: The findings confirm that psychiatric patients are at high risk of suicide. Patient outcomes in terms of risk of suicide after hospital discharge have deteriorated. IMPLICATIONS: Improvements are needed in the provision of community support to high risk psychiatric patients. Further work should be done to identify patients at highest risk of suicide.

Adult↗
PubMed1998

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

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.

Age Distribution↗
PubMed1998

Assessing the relationship between maternal opiate use and antepartum haemorrhage.

UNLABELLED: AIMS/DESIGN: Assessment of the association between the regular use of opiates by women during pregnancy and antepartum haemorrhage has been made difficult by the low prevalence of these conditions observed in clinical settings. As a consequence, most published studies lack statistical power due to the small number of cases. We combined all suitable published data in a meta-analysis to assess the association more accurately. FINDINGS: Meta-analysis produced a pooled estimate of the crude odds ratio for antepartum haemorrhage in relation to maternal opiate use of 2.33 (95% CI 1.32-4.30). CONCLUSIONS: This odds ratio estimate is consistent with a moderately strong association. Studies included did not adjust for possible confounders (e.g. prenatal care, cocaine or tobacco), so confounding is likely to account for at least some of the observed effect. The relative consistency of results from studies included in the meta-analysis that were conducted in different countries and at different times adds to the strength of the evidence for an association between opiate use and antepartum haemorrhage. Well designed studies are urgently required to assess the independent effects of different types and patterns of maternal opiate use and confounders such as cigarette smoking, illicit cocaine use and antenatal care on antepartum haemorrhage.

Female↗
PubMed1998

Assessing the relationship between maternal opiate use and neonatal mortality.

UNLABELLED: We undertook a number of meta-analyses to estimate more precisely the relationship between neonatal mortality and use of opiates in three groups of women. First, women who continued to use illicit heroin throughout pregnancy; secondly, women stabilized on methadone at the time of conception or shortly after and thirdly, women who use heroin well into pregnancy with late entry into methadone treatment, or who continued to use illicit heroin during pregnancy while receiving methadone. FINDINGS: The pooled estimates of the relative risks of neonatal mortality for separate heroin and methadone use were both near unity: 1.47 (95% CI 0.88-2.33) and 1.75 (95% CI 0.60-4.59), respectively. The result for heroin may be due to the inclusion in the meta-analysis of a particularly large study, which, unlike the two other smaller studies included found a relative risk near unity. When this study was excluded from the meta-analysis the pooled estimate of the relative risk of neonatal mortality for heroin use was 3.27 (95% CI 0.95-9.60). In contrast to the results for use of methadone only, the pooled relative risk associated with heroin and methadone use was 6.37 (95% CI 2.57-14.68). CONCLUSIONS: The increased relative risk for neonatal mortality associated with women using heroin and methadone during pregnancy, compared to those stabilized on methadone, is probably due to the chaotic and high-risk life-style associated with illicit heroin use and not solely to the use of heroin and methadone per se. It is recommended tht women who use heroin well into pregnancy with late entry into methadone treatment, or who continue to use illicit heroin during pregnancy while receiving methadone, receive special attention over and above that provided to women stabilized on methadone.

Female↗
PubMed1998

Population-based record linkage study of the incidence of abdominal aortic aneurysm in Western Australia in 1985-1994.

BACKGROUND: The incidence of abdominal aortic aneurysm (AAA) has increased steadily during the past 30 years. METHODS: Trends in the incidence and surgical intervention for AAA in Western Australia were reviewed for the interval 1985-1994. A population-based health database was used to link morbidity and mortality records of all patients aged 55 years or more who died from rupture or were admitted and treated surgically for AAA. Three groups were separated for analysis: patients with a ruptured AAA, those admitted for elective repair and those admitted as an emergency with an acute (non-ruptured) aneurysm. RESULTS: There was a decline in the incidence of both emergency and elective procedures for AAA after 1992. While the mortality rate from ruptured AAA has also fallen since 1991, the overall case fatality rate for ruptured AAA has fallen by only 1.3 per cent (from 80.7 to 79.3 per cent). CONCLUSION: The decline in mortality rate and emergency procedures may result from a fall in the incidence of ruptured AAA, due to an increasing rate of elective surgery before 1992. The decline in elective procedures from 1992 may be due to a fall in the prevalence of AAA owing to high rates of elective surgery, or to a fall in the incidence of the disease itself.

Age Distribution↗
PubMed1998

Assessing the reliability of a stage of change scale.

The purpose of this study was to assess the test-retest reliability of a scale measuring Prochaska's stages of change. Although structured questionnaire items are being increasingly used to segment target audiences according to Prochaska and DiClemente's stages of change, we could find only one report in the literature assessing the reliability of such scales. The unreliability of single-item or algorithm questionnaire scales might be why a number of studies show only minimal differences on some variables between individuals in different stages of change. A survey of the Perth metropolitan general population aged 16-69 years (N = 2629) was completed in August-September 1992 as part of a 3 year evaluation of the Western Australian Health Promotion Foundation. The consistency of respondents' responses was assessed across two questions measuring stages of change for the behaviours quitting smoking (n = 404), reducing alcohol consumption (n = 57) and doing more exercise (n = 704). Given the immediacy of the test-retest situation, the reliability results are moderately encouraging: kappa = 0.72, 0.73 and 0.52 for quitting smoking, reducing alcohol and doing more exercise, respectively. Health researchers should be aware of the probable moderate level of reliability if using the type of scale assessed in this study, when interpreting differences between individuals in different stages. In practice, several questionnaire items for classification purposes should be used so that internal reliability measures can be calculated. It is recommended that research be undertaken to devise more reliable scales for stages of change for the various health behaviours. It is noted that the attitude literature with respect to context and time specific intentions could be helpful in devising such scales.

Adolescent↗
PubMed1998

The Quality of Surgical Care Project: a model to evaluate surgical outcomes in Western Australia using population-based record linkage.

BACKGROUND: The aim of this study is to establish a model to evaluate surgical outcomes and, where indicated, recommend changes to improve the quality of surgical care in Western Australia (WA). Open resection for aneurysm of the abdominal aorta was the first procedure evaluated and the results are reported in an accompanying paper. METHODS: The Quality of Surgical Care Project (QSCP) is conducted under the aegis of the Royal Australasian College of Surgeons (RACS) in WA, and brings together a multidisciplinary team of surgeons, public health researchers and health service administrators. The Western Australia Health Services Research Linked Database (the WA Linked Database) is used to provide linked chains of patients records residing in the state health department from the following sources: hospital morbidity data system, birth and death records, mental health services data, cancer registrations and midwives' notifications. This links 16 years of population-based patient records from 1980, including all public and private hospital admissions and re-admissions. The Quality of Surgical Care Project was established to use and to correlate the data from the WA Linked Database. RESULTS: The result is a powerful database for a contained population that is available for scientific analysis by a multidisciplinary team of clinical epidemiologists, surgeons and health service managers. Users will have the ability to establish benchmark standards for the outcomes of surgical procedures in WA for use in quality improvement programmes run by the College and will facilitate self-directed performance auditing activities as a commitment to greater community accountability. CONCLUSIONS: The Quality of Surgical Care Project provides a potential model of benefits to be realized by both the medical profession and the community through multidisciplinary collaboration supported by adequate information. Although migration from WA is relatively low, future linkage to the state electoral roll will allow correction for any population change.

Aortic Aneurysm, Abdominal↗