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P Macaskill

Publications and source records attributed to P Macaskill.

At least 19 recordsLinked to original sources
PubMed2005

Meta-analysis of sentinel node imprint cytology in breast cancer.

BACKGROUND: Intraoperative diagnosis of breast cancer metastases in axillary sentinel nodes is desirable to avoid a second operation for lymphadenectomy. Imprint or touch-preparation cytology is a popular technique that has high specificity and a wide range of sensitivity. METHODS: A systematic search of electronic databases was performed. Included articles were assessed for methodological and reporting quality. Random-effects model pooled estimates of sensitivity and specificity were calculated. Single-variable and multivariable meta-regression analyses were performed for predictors of sensitivity. RESULTS: Thirty-one studies were included; all were of good methodological quality but reporting quality varied. Pooled sensitivity of imprint cytology was 63 (95 per cent confidence interval (c.i.) 57 to 69) per cent and specificity was 99 (95 per cent c.i. 98 to 99) per cent. Pooled sensitivity for macrometastases was 81 per cent and that for micrometastases 22 per cent. Mean or median primary tumour size (P = 0.004), the prevalence of metastases (P = 0.103) and the proportion of micrometastases (P = 0.022) were significant risk factors in single-variable meta-regression analysis. Only the proportion of micrometastases remained significant in multivariable analysis. Frozen sectioning had better sensitivity than imprint cytology in three of four direct comparisons. CONCLUSION: Imprint cytology is simple and rapid, and has good sensitivity for macrometastases. The significance of poor sensitivity for micrometastases will be determined by trials investigating their natural history.

Breast↗
PubMed2003

Progressive increase in incidence and prevalence of multiple sclerosis in Newcastle, Australia: a 35-year study.

The prevalence of multiple sclerosis (MS) in Newcastle, Australia increased significantly between 1961 and 1981 and the incidence of the disease also increased between the decades 1950-1959 and 1971-1981. The present study sought to determine whether there has been a further increase in the frequency of MS in the subsequent 15 years, and to examine the potential factors underlying this change. The incidence, prevalence and clinical profile of multiple sclerosis were therefore re-examined in Newcastle, Australia in 1996 using comparable diagnostic criteria and methods to those employed in studies in the same region in 1961 and 1981. There has been a significant progressive increase in prevalence from 19.6 to 59.1 per 100,000 population and a significant increase in incidence from 1.2 to 2.4 per 100,000 population from 1961 to 1996. The most pronounced increase in prevalence was in females and in the age-group over 60 years, and there was also an increased incidence in females aged 20-29 years. There was little change in the age of disease onset, but duration of disease in females had increased substantially. The significant increase in prevalence is attributed to increased incidence, particularly in females; and to increased survival. Although such trends in prevalence have been observed in the Northern Hemisphere, this is the first such study in the Southern Hemisphere to show a longitudinal increase in prevalence and incidence over a period of this duration.

Adolescent↗
PubMed2002

The comparative sensitivity of mammography and ultrasound in women with breast symptoms: an age-specific analysis.

Despite its importance for clinical policy, there is little research on the age at which ultrasound or mammography is the preferred initial diagnostic test in women with breast symptoms. We analysed data from a series of 3799 consecutively presenting cancers. The overall sensitivity was 77.6% for mammography and 80.5% for ultrasound. Sensitivity increased with age in both mammography and ultrasound, though more steeply for mammography. In the 975 women who had both tests, ultrasound had a higher sensitivity than mammography in women younger than 62 years of age, whereas mammography had a higher sensitivity than ultrasound in women older than 62 years. However, if the test results of the 2393 women who had mammography only are compared with the ultrasound results of the 975 women who had both tests, the 'cross-over' age at which the sensitivity of the two tests is equal occurs at the earlier age of 48 years. The presence of a palpable finding increases the sensitivity of ultrasound but does not influence the sensitivity of mammography.

Journal Article↗
PubMed2002

Evidence relevant to the investigation of breast symptoms: the triple test.

This paper reviews and summarises evidence on the investigation of breast symptoms based on triple testing. The triple test (where any component is positive) has a sensitivity of 99.6%, a specificity of 62%, a likelihood ratio of 2.62 for a positive result, and a likelihood ratio of 0.006 for a negative result. We present measures of test accuracy for the components of the triple test that allow easy estimation of the probability of breast cancer in symptomatic women, given any possible combination of results.

Journal Article↗
PubMed2001

A comparison of methods to detect publication bias in meta-analysis.

Meta-analyses are subject to bias for many of reasons, including publication bias. Asymmetry in a funnel plot of study size against treatment effect is often used to identify such bias. We compare the performance of three simple methods of testing for bias: the rank correlation method; a simple linear regression of the standardized estimate of treatment effect on the precision of the estimate; and a regression of the treatment effect on sample size. The tests are applied to simulated meta-analyses in the presence and absence of publication bias. Both one-sided and two-sided censoring of studies based on statistical significance was used. The results indicate that none of the tests performs consistently well. Test performance varied with the magnitude of the true treatment effect, distribution of study size and whether a one- or two-tailed significance test was employed. Overall, the power of the tests was low when the number of studies per meta-analysis was close to that often observed in practice. Tests that showed the highest power also had type I error rates higher than the nominal level. Based on the empirical type I error rates, a regression of treatment effect on sample size, weighted by the inverse of the variance of the logit of the pooled proportion (using the marginal total) is the preferred method.

Computer Simulation↗
PubMed2001

Sensitivity and specificity of tests to detect eye disease in an older population.

OBJECTIVE: To compare the ability of tests of visual function to detect the presence of eye disease. DESIGN: Cross-sectional study. PARTICIPANTS: Three thousand six hundred fifty-four of 4433 (82.4%) eligible residents of an area near Sydney aged 49 years and older had a detailed eye examination, including retinal and lens photography and subsequent grading of eye disease, tests of presenting and corrected visual acuity, contrast sensitivity, screening visual field and intraocular pressure. MAIN OUTCOME MEASURES: Receiver operator characteristic (ROC) curves were created and area under the curve compared for each vision test. Sensitivity and specificity were calculated for each test. RESULTS: No single vision test predicted the presence of eye disease with any consistency. Best-corrected visual acuity or contrast sensitivity had the highest area under the ROC curve for most eye diseases examined but had poor sensitivity and specificity. For glaucoma and diabetic retinopathy there was no difference in area under the curve for any of the tests examined, and no test had a good balance of sensitivity and specificity. Screening tests (performed with presenting correction) did not perform as well as nonscreening tests (those carried out after refraction with best correction). CONCLUSIONS: Current vision tests are not particularly good at detecting eye disease compared with the "gold standard" of a full eye examination performed by an ophthalmologist. Further work in this area should be carried out before vision screening programs can be recommended for implementation among older people.

Aged↗
PubMed2000

Multiple sclerosis in Australia: prognostic factors.

In order to determine the influence of age of onset, sex, onset symptoms, clinical course and interval from onset to first relapse on the subsequent outcome of multiple sclerosis (MS), data from 2934 cases of MS documented in a large population based study undertaken in Australia have been analysed. Disability on prevalence day (30 June 1981) was defined on the Kurtzke disability scale as mild (DSS 0-3), moderate (DSS 4-6) and severe (DSS 7-9). Prognostic factors associated with mild vs moderate/severe, and moderate vs severe disability on prevalence day were identified by logistic regression analysis. A worse prognosis was significantly associated with older age of onset, progressive disease course, onset symptoms that were multiple, pyramidal or cerebellar, and a short interval between onset and first relapse.

Adolescent↗
PubMed2000

Should we use carbohydrate-deficient transferrin instead of gamma-glutamyltransferase for detecting problem drinkers? A systematic review and metaanalysis.

BACKGROUND: Carbohydrate-deficient transferrin (CDT) has been used as a test for excessive alcohol consumption in research, clinical, and medico-legal settings, but there remain conflicting data on its accuracy, with sensitivities ranging from <20% to 100%. We examined evidence of its benefit over a conventional and less expensive test, gamma-glutamyltransferase (GGT), and compared the accuracy of different CDT assay methods. METHODS: We performed a systematic review using summary ROC analysis of 110 studies prior to June 1998 on the use of CDT in the detection of alcohol dependence or hazardous/harmful alcohol use. RESULTS: We identified several potential sources of bias in studies. In studies examining CDT and GGT in the same subjects, subject characteristics were less likely to influence the comparison. In such paired studies, the original Pharmacia CDT assay was significantly more accurate than GGT, but the modified CDTect assay did not perform as well as the original and was not significantly better than GGT. The accuracy of the AXIS %CDT assay was statistically indistinguishable from modified CDTect. Several CDT assay methods appeared promising, in particular, liquid chromatography (chromatofocusing, HPLC, fast protein liquid chromatography) and isoelectric focusing, but there were insufficient paired studies from which to draw firm conclusions. CONCLUSIONS: In studies published before June 1998, the results obtained with commercially available CDT assays were not significantly better than GGT as markers of excessive alcohol use in paired studies. Further high-quality studies comparing CDTect (modified) and other CDT assays with GGT in the same subjects are needed.

Age Factors↗
PubMed1999

Mastery of fundamental motor skills among New South Wales school students: prevalence and sociodemographic distribution.

Mastery of fundamental motor skills among children and adolescents is a potentially important contribution to satisfying participation in sports, games and other physical activities and may enhance the development of an active lifestyle. However, few attempts have been made to determine the prevalence of fundamental motor skill mastery among young Australians. The NSW Schools Fitness and Physical Activity Survey, 1997 (N = 5518) randomly selected schools proportionally from all three education sectors and selected students in Years 4, 6, 8 and 10. Performance on six fundamental motor skills (run, vertical jump, catch, overhand throw, forehand strike and kick) was assessed qualitatively. The prevalence of mastery and near mastery of each skill and mastery of each skill component is reported for boys and girls in each school year. The findings indicate that the prevalence of mastery and near mastery of each of the fundamental motor skills was generally low. There were no differences between students from urban or rural schools and the prevalence of skill mastery was directly associated with socioeconomic status more consistently among girls than among boys. Greater curriculum time and resourcing and training of teachers is required to increase the proportion of students who have mastered the skills fundamental to common sports, games and other physical activities.

Female↗
PubMed1999

Sociodemographic distribution of measures of body fatness among children and adolescents in New South Wales, Australia.

BACKGROUND: Obesity in childhood and adolescence is associated with health problems, increases in cardiovascular disease (CVD) risk factors and a greater likelihood of becoming overweight as an adult. A description of the sociodemographic distribution of overweight and obesity among children and adolescents in the population may allow us to determine if health promotion resources should be differentially allocated to particular groups. METHODS: The New South Wales Schools Fitness and Physical Activity Survey, 1997 (n = 5518) was a cross-sectional survey which measured height, weight, waist and hip girths and skinfold thicknesses of randomly selected New South Wales students in school years 4, 6, 8 and 10. Height and weight only were measured among Year 2 students. The mean ages of students in school years 2, 4, 6, 8 and 10 were 7.3y, 9.3y, 11.3y, 13.3y and 15.3y, respectively. The values of body mass index (BMI), waist girth, waist-to-hip ratio (WHR) and sum of three skinfolds for students resident in urban and rural areas and in tertiles of socioeconomic status (SES) were compared. RESULTS: There were no differences on any of the anthropometric measures between urban and rural boys and girls, with the exception that WHR was higher among urban girls. Among boys, there were no differences between the SES tertiles on any of the measures. Among girls, each of the anthropometric measures (except sum of skinfolds) was inversely associated with SES, with body fatness tending to be lower in the high SES tertile, compared with the low and middle SES tertiles. None of the statistical interactions between school year and body fatness was significant, suggesting that the relationship is consistent from childhood to adolescence. CONCLUSION: On the basis of these results, we suggest that health promotion programs aimed at weight management among Australian girls of lower SES are not warranted. We recommend that health promotion programs emphasize regular physical activity, a healthy diet and acceptance of the normal range of body shapes.

Adolescent↗
PubMed1999

Global burden of disease and injury due to occupational factors.

We made estimates of absolute morbidity and mortality due to occupational factors for the world using all available published data as of 1994, and, where no data were available, applying the most appropriate (in terms of similar economy, race, and environment) age-/sex-/diagnosis-specific incidence and mortality rates to known working population distributions. We report results according to economic groupings determined by the World Bank (World Development Report, 1993) and disease and injury groupings according to The Global Burden of Disease project (1997). This was part of a larger study that estimated the total global disease burden. We present aggregate results and analyses by region and disease. We estimate that approximately 100,000,000 occupational injuries (100,000 deaths) and 11,000,000 occupational diseases (700,000 deaths) occur in the world each year. We regard these as very conservative estimates which, although unavoidably crude, can nevertheless provide a basis for health priority planning at global level.

Adolescent↗
PubMed1999

Prevalence of chronic inflammatory demyelinating polyneuropathy in New South Wales, Australia.

A prevalence study of chronic inflammatory demyelinating polyneuropathy (CIDP) was performed in New South Wales (NSW), Australia, with a prevalence day of August 6, 1996, which coincided with a national census. The population of NSW was 5,995,544, and the crude prevalence of CIDP was 1.9 per 100,000 population. It was higher in male patients than in female patients, and the age-specific prevalence reached a maximum of 6.7 per 100,000 population in the 70- to 79-year-old age group. The prevalence in the city of Newcastle, with a population of 448,663, was 2.0 per 100,000 population and is representative of the whole of NSW. The estimated crude annual incidence was 0.15 per 100,000 population. The mean age of onset was 47.6 years (median, 53.5 years), 51% of patients had a relapsing-remitting course, the mean duration on prevalence day was 7.1 years (median, 5 years), and 87% of patients were able to walk without walking aids or other assistance.

Adolescent↗
PubMed1998

Methods of the NSW Schools Fitness and Physical Activity Survey, 1997.

Physical fitness, participation in physical activity, fundamental motor skills and body composition are important contributors to the health and the development of a healthy lifestyle among children and youth. The New South Wales Schools Fitness and Physical Activity Survey, 1997, was conducted to fill some of the gaps in our knowledge of these aspects of the lives of young people in New South Wales. The survey was conducted in February and March, 1997 and collected data on a randomly-selected sample of students (n = 5518) in Years 2, 4, 6, 8 and 10. Measures were taken on body composition (height and weight, waist and hip girths, skinfolds), health-related fitness (aerobic capacity, muscular strength, muscular endurance, flexibility), fundamental motor skills (run, vertical jump, catch, overhand throw, forehand strike and kick), self-reported physical activity, time spent in sedentary recreation, and physical education (PE) classes. The methods are described to assist in the development of surveys of other populations and to provoke debate relevant to the development and dissemination of standard approaches to monitoring the fitness, physical activity habits and body composition of Australian children and youth. Finally, we offer comments on some of the strengths and limitations of the methods employed.

Anthropometry↗
PubMed1997

Health risk and behaviour of out-of-school 16-year-olds in New South Wales.

This study describes the health risks and health behaviour of a sample of 283 out-of-school 16-year-olds in New South Wales. We sampled study participants through the Commonwealth Employment Service offices in 1994 using a multistage sampling procedure. Of those surveyed, 129 responded to a letter inviting them to participate and 154 were recruited opportunistically. This paper describes the study methods and results for self-reported binge drinking, weekly use of tobacco and marijuana, sexual abuse, physical abuse, drink-driving, violence, and use of health services, by sex and method of recruitment. High rates of substance use were observed. Reported substance use in the out-of-school group was consistently higher than for 16-year-olds in school, except for binge drinking for girls recruited by letter. Of the out-of-school group, 34 per cent reported weekly use of tobacco, marijuana and also binge drinking. Boys were more likely to report drink-driving than girls (28 per cent and 13 per cent respectively). Having been in trouble with police ranged from 32 per cent for girls recruited by letter to 75 per cent for boys recruited opportunistically. A high proportion of girls reported sexual abuse (34 per cent of the 'letter' group and 41 per cent of the 'opportunistic' group). Overall, 87 per cent of respondents had used health services in the previous year. The results indicate that this is a disadvantaged group of young people who are an important target for health service provision and interventions.

Adolescent↗
PubMed1996

Multiple sclerosis in Australia: socioeconomic factors.

The data from an epidemiological study on multiple sclerosis in Australia have been analysed to determine the relation between the prevalence of the disease and educational level, and the association between level of disability and employment status. There was a significantly higher frequency of multiple sclerosis in those who left school at an older age and achieved a higher educational level. The explanation of this finding remains speculative and may be related to genetic or environmental factors. The study confirmed the recognised association between moderate-severe disability and divorce-separation and lower rates of employment.

Adolescent↗
PubMed1995

Meta-analysis of Pap test accuracy.

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 = -0.63). Meta-analysis was used to combine data from 59 studies to estimate the accuracy of the Pap test using a summary receiver operating characteristic curve and to examine the effect of study quality. The summary receiver operating characteristic curve suggests that the Pap test may be unable to achieve concurrently high sensitivity and specificity. For example, specificity in the 90-95% range corresponds to sensitivity in the 20-35% range. Pap test accuracy was not associated with reported study characteristics or dimensions of quality. Future primary studies should pay more attention to methodologic standards for the conduct and reporting of diagnostic test evaluations.

Bias↗
PubMed1995

Meta-analytic methods for diagnostic test accuracy.

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. have developed a method to estimate Summary Receiver Operating Characteristic Curves, thereby taking account of possible test threshold differences between studies. Several methods are also available for analysing multicategory and continuous test data. The usefulness of applying these methods is constrained by publication bias and the generally poor quality of primary studies of diagnostic test accuracy. Meta-analysts need to highlight important defects in quality and how they affect summary estimates to ensure that better primary studies are available for meta-analysis in the future.

Bias↗