Publications by authors named "Irwig L"

Background: For early breast cancer, survival after breast conservation is similar to that after mastectomy. Some women may not have a clear preference and wish to have further information about quality of life experienced after the alternative treatments. This paper describes a systematic review of randomized trials on mastectomy versus breast conservation for which there are data on quality of life or psychosocial outcomes.

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Two dichotomous screening tests are often compared by performing both tests in a sampled population, and submitting positive results on either test to verification by the reference standard. Unbiased estimates of the true positive and false positive rates of each test cannot be estimated directly. However, unbiased estimates of the relative true positive and relative false positive rates may be obtained.

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Variability in the interpretation of micturating cystourethrography by paediatric radiologists for the diagnosis of vesicoureteric reflux in children was evaluated. All 265 micturating cystourethrograms (MCUs) that were available from 304 consecutive children aged 0.5-61 months-who were investigated after their first urine infection between 1993 and 1995 as part of a prospective cohort study-were selected for interpretation.

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Scales measuring commitment to abstinence-oriented policies, attitudes to drug addiction, and knowledge of methadone maintenance were refined and tested in a survey of staff working in 14 New York maintenance programs. Confirmatory factor analysis established the validity of a 9-item Abstinence Orientation Scale and a 6-item Disapproval of Drug Use Scale. Scores on the two scales and Knowledge scores were highly correlated.

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Using MEDLINE and the bibliographies of retrieved articles and reviews, we identified and systematically reviewed the quality and results of all randomized trials of mammographic screening that included women less than 50 years of age. Eight randomized trials were identified, 7 of which included women less than 50. Identified trials were assessed for the following design features: (a) method of randomization, (b) documented comparability of baseline data, (c) standardized criteria for breast cancer death, (d) blinded review of cause of death, (e) completeness of follow-up, and (f) use of an "intention to treat analysis.

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Objectives: To compare the accuracy of common commercial serological kits for Helicobacter pylori and to ascertain factors affecting accuracy.

Methods: A comprehensive MEDLINE and manual search strategy was used to identify all articles comparing two or more kits. Each article was critically appraised for sample characteristics, study design, and data handling.

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A study was undertaken to investigate the influence of methadone prescribers' commitment to abstinence-oriented policies on retention in their maintenance programs. Two hundred and eighty patients recently enrolled in single-person, private methadone programs were interviewed and followed for 8 years. The prescribing physicians' scores on an Abstinence Orientation Scale, derived from an independent sample of methadone program staff, were significantly associated with their patients' risk of premature discharge.

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The incremental costs and effects of annual faecal occult blood test screening in Australia were modelled for a hypothetical cohort of 1000 persons offered screening or not offered screening. Incremental costs and effects were estimated as the differences in direct health care costs (Australian costs) and years of life remaining between the annual-screen group and the control (no screen) group, based on the published results of the Minnesota randomised controlled trial. The cost per life year saved was $24,660.

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Two attitudinal scales measuring commitment to abstinence-oriented treatment policies and disapproval of illicit drug use were derived from a survey of 90 staff working in 10 public methadone maintenance clinics in Sydney, Australia. The two scales were shown to be valid constructs by confirmatory factor analysis and to be internally reliable and to have high test-retest reliability. The factors underlying the two scales were highly correlated (r = .

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To which groups of patients can the results of clinical trials be applied? This question is often inappropriately answered by reference to the trial entry criteria. Instead, the benefit and harm (adverse events, discomfort of treatment, etc) of treatment could be assessed separately for individual patients. Patients at greatest risk of a disease will have the greatest net benefit as benefit to patients usually increases with risk while harm remains comparatively fixed.

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We have developed the Psychosocial Effects of Abnormal Pap Smears Questionnaire (PEAPS-Q) which measures distress experienced by women undergoing follow-up investigation after an abnormal Pap smear result. A thorough literature review and qualitative research resulted in the development of a questionnaire which was tested on 350 women attending a Family Planning New South Wales (FPNSW) clinic. This sample included women at different stages of management after detection of a cervical abnormality: 93 first colposcopy clients and 257 follow-up colposcopy clients.

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This study aimed to examine whether knowledge, attitudes and concerns predicted attendance at the mobile Breast X-Ray Programme in Sydney. A cohort study design was used, whereby women were surveyed prior to the implementation of the program, and two years later records were checked to determine whether they had attended for screening. Telephone interviews were sought with randomly selected women aged 45 to 70 years living in the central Sydney area (the screening van's catchment area).

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A literature search identified 62 studies published by August 1992 comparing Papanicolaou (Pap) test results with histology. Critical appraisal revealed that 82% of these had potential for verification bias and that only 37% stated that cytology and histology were independently assessed. Estimates of sensitivity and specificity ranged from 11 to 99% and 14 to 97%, respectively, and were highly negatively correlated (r = -0.

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To assess the utility of a new, rapid, economical procedure that may prove valuable in cervical screening, Fourier transform infrared (ir) spectroscopy was performed on 25 cervicovaginal lavage specimens from women referred for colposcopy on the basis of a cytological abnormality detected on their Pap smear and whose lavage specimen was positive for human papillomavirus. Of the 18 classed as CIN I or less by histopathology, 11 showed band frequencies that deviated only slightly from spectra that characterize normal cervical cells and 3 of 5 "atypia" specimens had spectra identical to normal. Two of 3 classed as CIN II had spectra only slightly more abnormal to these 11.

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Australian guidelines for colorectal cancer screening for average-risk populations vary from recommendations for annual screening by faecal occult blood testing for those over 40 years to recommendations that screening may be appropriate if requested by an informed patient aged 50 to 75 years. There are five large screening trials, of which three have published mortality data. A meta-analysis of the mortality data suggests a 19 per cent reduction in colorectal cancer mortality (95 per cent confidence intervals 0.

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Meta-analyses of diagnostic test accuracy are uncommon and often based on separate pooling of sensitivity and specificity, which can lead to biased estimates. Recently, several appropriate methods have been developed for meta-analysing diagnostic test data from primary studies. Primary studies usually only provide binary test data, for which Moses et al.

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Objective: To identify environmental factors involved in the etiology of insulin-dependent diabetes mellitus (IDDM).

Research Design And Methods: An estimated 90% of all incident cases of IDDM in patients 0-14 years of age in New South Wales, Australia, were ascertained over 18 months. For each IDDM patient, two age- and sex-matched control subjects were randomly selected from the population.

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The aim of this study was to determine whether Pap smear screening at adequate intervals is associated with area of residence, frequency of consultations with a general practitioner, socioeconomic status and non-English-speaking background. A representative 10 per cent sample of women from New South Wales and the Australian Capital Territory, aged 25 to 69 years and registered with the Health Insurance Commission (Medicare) (N = 155,281) was used to obtain age, postcode, frequency of Pap smears and frequency of consultations with general practitioners in the three-year period from February 1985 to January 1988. Census data for each postcode area were used as an indicator of other socio-demographic characteristics.

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Objective: To evaluate the efficacy of paracetamol and a non-steroidal anti-inflammatory drug for symptom relief in osteoarthritis.

Design: Double blind, randomised, controlled trials in individual patients (n of 1 trials). Three treatment cycles with two weeks' each of paracetamol (1 g twice daily) and diclofenac (50 mg twice daily) prepared in identical gelatin capsules.

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Evaluating a screening test often requires estimation of test sensitivity and specificity with appropriately narrow confidence intervals and at least cost. If the major cost is the reference ("gold") standard, savings arise from reducing the large number of test negatives that are verified by the reference standard. On the basis of the formulae of Begg and Greenes (Biometrics 1983;39:207-15), the authors determine the optimal sampling strategy for test positives and test negatives to minimize the total sample size that needs to be verified for a given confidence interval width for sensitivity.

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We examined the psychosocial impact of implementing a generalised campaign to promote mammography screening in an Australian inner city community. Prior to the campaign, telephone interviews were conducted with 628 randomly selected women aged 45-70, 285 in central Sydney (where the screening programme operated) and 343 from the rest of Sydney. A second cross-sectional survey was conducted two years after the campaign commenced.

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