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Biomedical subjects

Neil Pearce

Publications and source records attributed to Neil Pearce.

At least 19 recordsLinked to original sources
PubMed2006

Bias in occupational epidemiology studies.

The design of occupational epidemiology studies should be based on the need to minimise random and systematic error. The latter is the focus of this paper, and includes selection bias, information bias and confounding. Selection bias can be minimised by obtaining a high response rate (and by appropriate selection of the control group in a case-control study). In general, it is important to ensure that information bias is minimised and is also non-differential (for example, that the misclassification of exposure is not related to disease status) by collecting data in a standardised manner. A major concern in occupational epidemiology studies usually relates to confounding, because exposure has not been randomly allocated, and the groups under study may therefore have different baseline disease risks. For each of these types of bias, the goal should be to avoid the bias by appropriate study design and/or appropriate control in the analysis. However, it is also important to attempt to assess the likely direction and strength of biases that cannot be avoided or controlled.

Bias↗
PubMed2006

Maternal complications and procedures in pregnancy and at birth and wheezing phenotypes in children.

RATIONALE: There is increasing interest in the potential influence of fetal and early life conditions on childhood wheezing. OBJECTIVES: To investigate the associations between maternal complications and procedures in pregnancy and at birth and the risk of various wheezing phenotypes in young children. METHODS: We studied 15,609 children, aged 6-7 yr, enrolled in a population-based study. Standardized questionnaires were completed by the children's mothers. RESULTS: Of the children, 9.5% (1,478) had transient early wheezing, 5.4% (884) had persistent wheezing, and 6.1% (948) had late-onset wheezing. Maternal hypertension or preeclampsia was associated with an increased risk of all three wheezing phenotypes (for transient early wheezing: odds ratio [OR], 1.40; 95% confidence interval [95% CI], 1.08-1.82; for persistent wheezing: OR, 1.59; 95% CI, 1.15-2.19; and for late-onset wheezing: OR, 1.47; 95% CI, 1.06-2.01). Use of antibiotics for urinary tract infections was associated with transient early wheezing (OR, 1.52; 95% CI, 1.16-2.00), whereas antibiotic administration at delivery was associated with both transient early wheezing (OR, 1.21; 95% CI, 1.01-1.46) and persistent wheezing (OR, 1.39; 95% CI, 1.10-1.75). Children who had a mother with diabetes were also more likely to have persistent wheezing (OR, 1.72; 95% CI, 0.99-3.00). Neither amniocentesis/chorionic villus sampling, nor weight gain in pregnancy, nor cesarean section was associated with the subsequent development of wheezing. Maternal asthma or atopy was not an effect modifier of the associations found. CONCLUSIONS: Some maternal complications during pregnancy and at delivery may increase the risk of developing different phenotypes of wheezing in childhood.

Child↗
PubMed2006

Prevalence of undiagnosed metabolic syndrome in a population of adult asymptomatic subjects.

BACKGROUND: To evaluate in the general population the prevalence of undiagnosed metabolic syndrome (MS), defined according to the National Cholesterol Education Program (NCEP) and International Diabetes Federation (IDF) criteria. METHODS: A population-based cross-sectional study of 1175 asymptomatic adults in North-Western Italy. RESULTS: The prevalence of undiagnosed MS was 16.4% (95% CI=14.4-18.6) (NCEP) and 28.0% (25.4-30.6) (IDF), respectively, 5.2% (3.6-7.3) and 8.9% (6.6-11.3) in normal-BMI and 26.6% (23.3-30.2) and 45.3% (41.3-49.2) in overweight/obese individuals. Of the total cohort, 52% were overweight/obese and they accounted for 85% of the cases of MS; a further 19% were normal weight with light physical activity and accounted, respectively, for 12% (NCEP) and 13% (IDF) of the cases. Only 25% (NCEP) and 14% (IDF) of participants showed no component of the MS (respectively, 40 and 26% of those not-overweight and 11 and 3% of those overweight/obese). CONCLUSIONS: More than 97% of unknown MS cases would be identified among apparently healthy individuals when overweight/obese, and normal-BMI subjects with low physical activity were screened. These two criteria might, therefore, be used to prioritise screening programmes in asymptomatic subjects, since even apparently healthy individuals, who are not-overweight, frequently show one or more metabolic abnormalities, whose co-existence has been demonstrated to be hazardous.

Cross-Sectional Studies↗
PubMed2006

Improving access to health care among New Zealand's Maori population.

The health status of indigenous peoples worldwide varies according to their unique historical, political, and social circumstances. Disparities in health between Maoris and non-Maoris have been evident for all of the colonial history of New Zealand. Explanations for these differences involve a complex mix of components associated with socioeconomic and lifestyle factors, availability of health care, and discrimination. Improving access to care is critical to addressing health disparities, and increasing evidence suggests that Maoris and non-Maoris differ in terms of access to primary and secondary health care services. We use 2 approaches to health service development to demonstrate how Maori-led initiatives are seeking to improve access to and quality of health care for Maoris.

Community Participation↗
PubMed2006

Bladder cancer risk in sales workers: artefact or cause for concern?

BACKGROUND: A large number of epidemiological studies have reported positive associations between bladder cancer and sales occupations. We investigated whether these findings are likely to be due to chance, confounding or publication bias, or may involve causal associations. METHODS: Studies reporting bladder cancer risk-estimates for sales occupations were reviewed. Using meta-analyses we assessed heterogeneity and publication bias, and derived summary estimates. RESULTS: Eighteen publications were identified, reporting 85 risk-estimates for sales-work. Meta-estimates were elevated for men (odds ratio (OR) 1.11, 95% confidence interval (CI) 1.01-1.21) and women (OR = 1.36, 95% CI = 1.11-1.67). The estimate was heterogeneous for men (p(Q-test) <0.01, women: 0.18) and indicated publication bias for women (p(Egger-test) <0.01, men: 0.40). When including only smoking-adjusted estimates reported irrespective of the strength of the association, the summary estimate for generic groups of sales workers was 0.99 (95% CI 0.90-1.08) for men, and 1.18 (95% CI = 0.99-1.39) for women, without statistically significant heterogeneity or publication bias. For women, risk was positively associated with longer duration of sales-employment in three studies. CONCLUSIONS: Publication bias explained most of the reported increased bladder cancer risk, but sales-work still appeared to be associated with a small risk in women. Possible causal factors include lower frequency of urination and reduced fluid intake.

Bias↗
PubMed2006

Cancer mortality in workers exposed to organochlorine compounds in the pulp and paper industry: an international collaborative study.

The objective of this study was to evaluate cancer mortality in pulp and paper industry workers exposed to chlorinated organic compounds. We assembled a multinational cohort of workers employed between 1920 and 1996 in 11 countries. Exposure to both volatile and nonvolatile organochlorine compounds was estimated at the department level using an exposure matrix. We conducted a standardized mortality ratio (SMR) analysis based on age and calendar-period-specific national mortality rates and a Poisson regression analysis. The study population consisted of 60,468 workers. Workers exposed to volatile organochlorines experienced a deficit of all-cause [SMR = 0.91; 95% confidence interval (CI), 0.89-0.93] and all-cancer (SMR = 0.93; 95% CI, 0.89-0.97) mortality, with no evidence of increased risks for any cancer of a priori interest. There was a weak, but statistically significant, trend of increasing risk of all-cancer mortality with increasing weighted cumulative exposure. A similar deficit in all-cause (SMR = 0.94; 95% CI, 0.91-0.96) and all-cancer (SMR = 0.94; 95% CI, 0.89-1.00) mortality was observed in those exposed to nonvolatile organochlorines. No excess risk was observed in cancers of a priori interest, although mortality from Hodgkin disease was elevated (SMR = 1.76; 95% CI, 1.02-2.82) . In this study we found little evidence that exposure to organochlorines at the levels experienced in the pulp and paper industry is associated with an increased risk of cancer, apart from a weak but significant association between all-cancer mortality and weighted cumulative volatile organochlorine exposure.

Humans↗
PubMed2005

Bayesian methods for early detection of changes in childhood cancer incidence: trends for acute lymphoblastic leukaemia are consistent with an infectious aetiology.

Published data on time trends in the incidence of childhood leukaemia show inconsistent patterns, with some studies showing increases and others showing relatively stable incidence rates. Data on time trends in childhood cancer incidence from the Childhood Cancer Registry of Piedmont, Italy were analysed using two different approaches: standard Poisson regression and a Bayesian regression approach including an autoregressive component. Our focus was on acute lymphoblastic leukaemia (ALL), since this is hypothesised to have an infectious aetiology, but for purposes of comparison we also conducted similar analyses for selected other childhood cancer sites (acute non-lymphoblastic leukaemia (AnLL), central nervous system (CNS) tumours and neuroblastoma (NB)). The two models fitted the data equally well, but led to different interpretations of the time trends. The first produced ever-increasing rates, while the latter produced non-monotonic patterns, particularly for ALL, which showed evidence of a cyclical pattern. The Bayesian analysis produced findings that are consistent with the hypothesis of an infectious aetiology for ALL, but not for AnLL or for solid tumours (CNS and NB). Although sudden changes in time trends should be interpreted with caution, the results of the Bayesian approach are consistent with current knowledge of the natural history of childhood ALL, including a short latency time and the postulated infectious aetiology of the disease.

Adolescent↗
PubMed2005

Ethnic differences in cause specific mortality among hospitalised patients with diabetes: a linkage study in New Zealand.

STUDY OBJECTIVE: To describe patterns of excess mortality among patients with diabetes in three ethnic groups. DESIGN: A linkage study of national hospital discharge records to death records. SETTING: New Zealand. PARTICIPANTS: The study included 74 847 patients (11,268 Māori, 5730 Pacific, and 57,849 non-Māori/non-Pacific) aged over 25 years with a hospital discharge diagnosis of diabetes between 1988 and 2001. By the end of 2001, 29,295 (39%) of the cohort had died. Based on the underlying cause of death, standardised mortality ratios (SMRs) (95% confidence intervals) were calculated for each ethnic group and sex. MAIN RESULTS: Comparing the mortality patterns of patients with diabetes to the general population of the same ethnic group, adjusting for age and calendar period, all cause SMRs were higher for Māori women and men: 3.80 (95% CI: 3.64 to 3.97) and 3.44 (95%CI: 3.30 to 3.58) than for Pacific (men: 2.41 (95%CI: 2.21 to 2.61); women: 2.23 (95%CI: 2.06 to 2.41)) and non-Māori/non-Pacific (men: 2.98 (95%CI: 2.93 to 3.04); women: 2.99 (95%CI: 2.93 to 3.04)) people. SMRs were significantly raised for several causes of death, including cardiovascular disease and many site specific cancers. CONCLUSIONS: The pattern of excess mortality among Māori with diabetes may relate to severity of disease. This needs further investigation, as the excess mortality may be amenable to intervention.

Cause of Death↗
PubMed2005

Ethnic inequalities in cancer survival in New Zealand: linkage study.

We explored the contribution of stage at diagnosis to ethnic disparities in cancer survival in New Zealand. We linked 115811 adult patients with invasive cancer registered on the cancer registry (1994 to 2002) to mortality data. Age-standardized, 5-year relative survival rates were lowest for Maori, intermediate for Pacific people (otherwise known as Pacific Islanders), and highest for non-Maori/non-Pacific people for many cancers. Stage at diagnosis accounted for only part of these differences. Possible factors responsible for ethnic inequalities might include access to specialized cancer services and the quality of care received.

Adolescent↗
PubMed2005

Quantitative estimates of work-related death, disease and injury in New Zealand.

OBJECTIVES: New Zealand lacks comprehensive statistics on work-related injury and illness, and the impact of adverse work conditions on health is therefore not known. The objective of this study was to make quantitative estimates of the annual number of deaths from work-related disease and injury in New Zealand, as well as estimate the number of incident cases of work-related disease and injury. METHODS: Wherever possible, specific data for New Zealand were used, but, where adequate national data were lacking, a combination of New Zealand data and extrapolations from other countries was used. For work-related injury mortality and incidence, published studies and reports of the New Zealand Accident Compensation Corporation were primarily used. For work-related disease mortality, the likely population attributable fractions from overseas studies were mainly used, together with mortality data from New Zealand. For work-related disease incidence, both approaches were used. RESULTS: In New Zealand about 700-1000 deaths were estimated to occur annually from work-related disease and about 100 deaths from work-related injury. About 17 000-20 000 new cases of work-related disease occur annually and about 200 000 work-related accidents result in claims made to the New Zealand Accident Compensation Corporation. CONCLUSIONS: Despite their imprecision, these conservative estimates indicate the burden of work-related death, disease, and injury in New Zealand. The estimates by gender, industry, and disease types provide useful information for policy priorities.

Accidents, Occupational↗
PubMed2005

Temporal trends in the incidence of childhood leukemia, lymphomas and solid tumors in north-west Italy, 1967-2001. A report of the Childhood Cancer Registry of Piedmont.

BACKGROUND AND OBJECTIVES: Several studies have been published on trends in childhood cancer incidence, with different patterns being reported. We present an analysis of cancer incidence trends in Piedmont (Italy) in 1967-2001 for the major categories of childhood malignant neoplasms. DESIGN AND METHODS: The population-based Childhood Cancer Registry of Piedmont has recorded incident cases of malignant neoplasm in children (age 0-14) since 1967. Procedures for data collection and coding have been uniform throughout the study period. We calculated incidence rates per million children per year by sex and age-group. Trends were estimated using Poisson regression analysis, adjusted for age and sex and presented as the annual percent change (APC). RESULTS: Significant increases were observed for all malignant neoplasms combined (3360 cases, APC:1.3%, 95% CI:1.0% to 1.6%), leukemia (APC: 1.0%, 95% CI: 0.4% to 1.6%), central nervous system (CNS) tumors (APC of 2.3%, 95% CI: 1.6% to 3.1%) and neuroblastoma (APC: 2.3%, 95% CI: 1.0% to 3.5%). Acute lymphoblastic leukemia (APC 1.2%, 95% CI: 0.2% to 2.3%), and Acute non-lymphoblastic leukemia (APC 1.7%, 95% CI-0.6%, 4.1) both increased over time. Differences by age groups were observed for some tumor types, such as for neuroblastoma in infants (4.8% increase per year), leukemia in children aged 1-4 years (1.2%) and CNS tumors in children aged 10-14 (3.4%). INTERPRETATION AND CONCLUSIONS: Our data suggest an increasing incidence of childhood cancer in general, and specifically for leukemia, CNS tumors and neuroblastoma in Piedmont in 1967-2001. The observed trends are unlikely to be explained by random variation, changes in exhaustiveness or quality of data collection and registration.

Adolescent↗
PubMed2005

Agricultural exposures and non-Hodgkin's lymphoma.

Farmers have an increased risk of non-Hodgkin's lymphoma (NHL), several studies have found increased risks of NHL among producers or sprayers of pesticides. The findings are markedly inconsistent across countries and studies, but overall there is evidence of an increased risk among production workers and professional pesticide sprayers with heavy exposures. However, this increased risk does not appear to be confined to workers exposed to phenoxy herbicides containing 2,3,7,8-tetrachlorodibenzo-p-dioxin, and it may be due to phenoxy herbicide exposure itself rather than to the dioxin contaminants. Other pesticide exposures, including organochlorine and organophosphorous insecticides, have also been associated with NHL in some studies, as have nitrates in drinking water. Farmers may also have exposure to oncogenic viruses carried by farm animals, and studies of slaughterhouse workers and meat inspectors have found increased risks of NHL.

Agricultural Workers' Diseases↗
PubMed2004

The globalization of epidemiology: introductory remarks.

We are all living in the era of globalization, and like it or not, it is going to change the way we practice epidemiology, the kinds of questions we ask, and the methods we use to answer them. Increasingly, pubic health problems are being shifted from rich countries to poor countries and from rich to poor populations within Western countries. There is increasing interest and concern about the situation in non-Western populations on the part of Western epidemiologists, with regards to collaborative research, skills transfer, and 'volunteerism' to enable the 'benefits' of Western approaches to epidemiology to be shared by the non-Western world. However, most existing collaborations benefit Western epidemiologists rather than the countries in which the research is conducted. Even when research in non-Western populations is conducted as a genuine collaboration, it can too often 'export failure' from the West. On the other hand, non-Western epidemiologists are increasingly developing new and innovative approaches to health research that are more appropriate to the global public health issues they are addressing. These include recognition of the importance of context and the importance of diversity and local knowledge, and a problem-based approach to addressing the major public health problems using appropriate technology. These debates formed the background for a plenary session on 'International Epidemiology and International Health' at the recent International Epidemiological Association (IEA) meeting in Montreal, and the papers from this session are presented here. The development of a truly global epidemiology can not only better address the public health problems in non-Western populations, but can shed light on the current limitations of epidemiology in addressing the major public health problems in the West.

Developing Countries↗
PubMed2004

Respiratory symptoms and lung function change in welders: are they associated with workplace exposures?

AIMS: This study investigates whether work-related respiratory symptoms and acute falls in forced expiratory volume in 1 second (FEV1), previously observed in current welders, are related to measured workplace exposures to total fume and metals. METHODS: At four work sites in New Zealand, changes in pulmonary function (and reported respiratory symptoms) were recorded in 49 welding workers (and 26 non-welders) exposed to welding fume. We also determined the personal breathing zone levels of total fume and various metals. RESULTS: Work-related respiratory symptoms were reported by 26.5% of welders and 11.5% of non-welders. These symptoms were related significantly to their personal breathing zone nickel exposure--with an adjusted odds ratio (OR) and 95% confidence interval [CI] of the high exposure group (compared to a low exposure group of 7.0 [1.3-36.6]). There were non-significant associations with total fume exposure (OR = 2.6, 95% CI 0.6-12.2), and exposure index of greater than 10 years (OR=2.8, 95% CI 0.5-15.0). A fall in FEV1 of at least 5% after 15 minutes of work was significantly associated with aluminium exposure (OR=5.8, 95% CI 1.7-20.6). CONCLUSIONS: Nickel exposure from metal inert gas (MIG) and tungsten inert gas (TIG) welding is associated with work-related respiratory symptoms and aluminium exposure from welding is associated with a fall in FEV1 of at least 5 % after 15 minutes of work.

Adolescent↗