Interpretation of results
Various analysis techniques showed there are significant relationships between the risk factors and COPD. Most of the risk factors indicated significant relationships with the disease, while others indicated protective outcomes. The sample size for this research was 1519 individuals. From the author’s bivariate analysis of the place of residence indicates that a participant residing in an urban area gives (OR= 1.62, p<0.0001, 95% CI [13.4, 1.94]). This result indicates that the participant has a notable risk of contracting COPD (pg 6). The association between lack of leisure time activities and COPD is explained as significant with (OR = 1.33, p = 0.01, 95% CI [1.06, 1.68]). According to the analysis, one-hour weekly sporting activity protects workers against COPD. The result of association between sporting exercise and COPD was as follows; (OR = 0.65, p = 0.002, 95% CI [0.49, 0.86]). The p-value indicates that a person that carries out regular negative sporting exercises has a lower probability of contracting COPD, regardless of their occupation.
Multivariate analysis shows that several occupational risk factors were significant concerning the disease. The results indicate that there is a strong association between foundry and COPD. The report showed the following outcome; the p-value is less than 0.0001; the CI is 95% with a range of [4.5, 12.9]. The statistic p< 0.0001 implies that foundry is a significant risk factor for COPD. The results also show that tooling and textile occupations have a weak association with the disease. The p-values of tooling and textiles were 0.02 and 0.06, respectively. The values indicate that people working in these two occupations are a lower risk of suffering from COPD. The research also found that farming and pottery are a protective factor.
Statistically, the outcome might change if a larger sample of workers is available for this study. The smaller sample sizes of the occupational risk factors made it challenging to control for confounding factors in the study. The results are, therefore, subject to selection bias. The selection of individuals for the eleven occupations was the cause of the bias. The significance of the results cannot be reliable since the confounding variables also affected the results. Another bias in this study could have been information bias. The recall bias may influence the reliability of data on smoking history. Some of the workers may not remember their account of exposure to smoking. Bias reduction was by use of a professional in helping workers to fill questionnaires (pg 8). The author addresses various limitations in the discussion. The factors analyzed were mainly four; farming 8.7%, foundry 13.3%, woodworking 7.3%, machine/tooling 10.8%. The small samples in each risk factor may have led to non-differential misclassification. The author explains that foundry has a high prevalence of COPD, and the study is applicable in this occupational sector to help create a working environment that prevents the occurrence of the disease.