Occupational Exposures and Ischaemic Heart Disease: Results from The Entire New Zealand Population

Introduction Ischaemic Heart Disease (IHD) is a leading cause of death in Western countries. Common occupational exposures such as loud noise, long working hours, and sedentary work have been associated with increased IHD risks, but inconsistently. Objectives and Approach This study examines associations between incident IHD and exposure to long working hours, sedentary work, and loud noise. Individual-level microdata from Statistics New Zealand Integrated Data Infrastructure (IDI) were extracted for adults (age 20-64 years) with occupation recorded on the 2013 Census. The number of working hours was extracted from the Census, and exposure to sedentary work and loud noise was assessed through job exposure matrices (JEMs). IHD events (from 2013 to end of 2018) were identified using hospitalisations, prescriptions and deaths. Hazard ratios (HRs) were calculated using cox regression adjusted for age, socioeconomic status, and smoking. Results were stratified by sex and ethnicity. Results A total of 20,610 IHD cases were identified from 1,594,680 individuals employed at time of Census. Both short (90% of the time compared to 90dBA) compared to no exposure (<80dBA) was associated with elevated HRs without reaching statistical significance (HR(Non-Māori)=1.12, 95%CI=0.96-1.29; HR(Māori)=1.25, 95%CI=0.89-1.75). For females exposure to the 80-85dBA category compared to no exposure also showed elevated HRs (HR(Non-Māori)=1.14; 95%CI=1.04-1.26; HR(Māori)=1.16; 95%CI=0.93-1.46), but too few females were employed in jobs with the highest noise exposure. Conclusion These preliminary analyses do not support sedentary work or long working hours as IHD risk factors, but do suggest a modest increase in IHD risk associated with occupational exposure to noise.FALS

Occupational groups and ischaemic heart disease in New Zealand – a longitudinal linkage study

Abstract Background/Introduction Occupation is a poorly characterised risk factor for cardiovascular disease (CVD), with females and minority populations particularly under-represented in research. There is also a lack of longitudinal studies using detailed health data that does not rely on self-reports. Purpose This study aimed to address these gaps by assessing the association between a range of occupational groups and ischaemic heart disease (IHD) in New Zealand (NZ), through linkage of population-based occupational surveys to routinely collected health data. Half of the study population were females and 40% were indigenous Māori (who comprise 15% of the total 4.8 million NZ population), which enabled sex and ethnicity-specific aspects of the relationship between occupation and IHD to be assessed. Methods Two probability-based sample surveys of the NZ adult population (New Zealand Workforce Survey (NZWS); 2004–2006; n=3003) and of the Māori population (NZWS Māori; 2009–2010; n=2107), for which detailed occupational histories and lifestyle factors were collected, were linked with routinely collected health data available through Statistics NZ. Cox regression was used to calculate hazard ratios (HR) for “ever-worked” in any one of nine major occupational groups, with “never worked” in that occupational group defined as the reference group. Analyses were controlled for age, deprivation and smoking, and stratified by sex and ethnicity. Results The strongest associations were found for “plant/machine operators and assemblers” and “elementary workers”, particularly among female Māori (HR 2.19, 95% CI 1.16–4.13 and HR 2.03, 1.07–3.82 respectively). In contrast, inverse associations with IHD across all groups were observed for “technicians and associate professionals”, which was significant for NZWS males (HR 0.52, 0.32–0.84). There were some sex and ethnic differences, particularly for “clerks”, where a positive association was found for NZWS males (HR 1.81, 1.19–2.74), whilst an inverse association was observed for Māori females (HR 0.42, 0.22–0.82). Duration analyses (≤2 years, 2–10 years and 10+ years) showed significant dose-response trends for “clerks” in NZWS males, and “plant/machine operators and assemblers” and “elementary workers” in Māori females. Further adjustments for other potential confounders such diabetes mellitus, hypertension and high cholesterol did not affect the results. Conclusion Associations between occupation and IHD differed significantly across occupational groups and between sexes and ethnicities, even within the same occupational groups. This suggests that results may not be generalised across these groups and occupational interventions to reduce IHD risk may therefore need different approaches depending on the population and specific groups of interest. Funding Acknowledgement Type of funding source: Other. Main funding source(s): Health Research Council (HRC) of New Zealand </jats:sec

Occupation and motor neuron disease : A New Zealand case-control study

Objectives: To assess associations between occupation and motor neuron disease (MND). Methods: We conducted a population-based case-control study with cases (n=321) recruited through the New Zealand Motor Neurone Disease Association and hospital discharge data. Controls (n=605) were recruited from the Electoral Roll. Information on personal and demographic details, lifestyle factors and a full occupational history was collected using questionnaires and interviews. Associations with ever/never employed and employment duration were estimated using logistic regression stratified by sex and adjusted for age, ethnicity, socioeconomic deprivation, education and smoking. Results: Elevated risks were observed for field crop and vegetable growers (OR 2.93, 95% CI 1.10 to 7.77); fruit growers (OR 2.03, 95% CI 1.09 to 3.78); gardeners and nursery growers (OR 1.96, 95% CI 1.01 to 3.82); crop and livestock producers (OR 3.61, 95% CI 1.44 to 9.02); fishery workers, hunters and trappers (OR 5.62, 95% CI 1.27 to 24.97); builders (OR 2.90, 95% CI 1.41 to 5.96); electricians (OR 3.61, 95% CI 1.34 to 9.74); caregivers (OR 2.65, 95% CI 1.04 to 6.79); forecourt attendants (OR 8.31, 95% CI 1.79 to 38.54); plant and machine operators and assemblers (OR 1.42, 95% CI 1.01 to 2.01); telecommunications technicians (OR 4.2, 95% CI 1.20 to 14.64); and draughting technicians (OR 3.02, 95% CI 1.07 to 8.53). Industries with increased risks were agriculture (particularly horticulture and fruit growing), construction, non-residential care services, motor vehicle retailing, and sport and recreation. Positive associations between employment duration and MND were shown for the occupations fruit growers, gardeners and nursery growers, and crop and livestock producers, and for the horticulture and fruit growing industry. Conclusions: This study suggests associations between MND and occupations in agriculture and several other occupations

A longitudinal linkage study of occupation and ischaemic heart disease in the general and Māori populations of New Zealand

Objectives Occupation is a poorly characterised risk factor for cardiovascular disease (CVD) with females and indigenous populations under-represented in most research. This study assessed associations between occupation and ischaemic heart disease (IHD) in males and females of the general and Māori (indigenous people of NZ) populations of New Zealand (NZ). Methods Two surveys of the NZ adult population (NZ Workforce Survey (NZWS); 2004-2006; n = 3003) and of the Māori population (NZWS Māori; 2009-2010; n = 2107) with detailed occupational histories were linked with routinely collected health data and followed-up until December 2018. Cox regression was used to calculate hazard ratios (HR) for IHD and “ever-worked” in any of the nine major occupational groups or 17 industries. Analyses were controlled for age, deprivation and smoking, and stratified by sex and survey. Results 'Plant/machine operators and assemblers' and 'elementary occupations' were positively associated with IHD in female Māori (HR 2.2, 95%CI 1.2-4.1 and HR 2.0, 1.1-3.8, respectively) and among NZWS males who had been employed as 'plant/machine operators and assemblers' for 10+ years (HR 1.7, 1.2-2.8). Working in the 'manufacturing' industry was also associated with IHD in NZWS females (HR 1.9, 1.1-3.7), whilst inverse associations were observed for 'technicians and associate professionals' (HR 0.5, 0.3-0.8) in NZWS males. For 'clerks', a positive association was found for NZWS males (HR 1.8, 1.2-2.7), whilst an inverse association was observed for Māori females (HR 0.4, 0.2-0.8). Conclusion Associations with IHD differed significantly across occupational groups and were not consistent across males and females or for Māori and the general population, even within the same occupational groups, suggesting that current knowledge regarding the association between occupation and IHD may not be generalisable across different population groups