A Statistical Analysis Method of the Standard Mortality by Occupational Classes and Causes of Death in Cluj Napoca, 2002
The mortality study consisted of 2893 persons who died in the city of Cluj-Napoca in the year 2002. Details from death records and occupations were extracted from the death certificates and working documents. Information included name, gender, date of birth, date of death, place of living, level of education, occupation and cause of death. Mortality data were analysed in terms of cause-specific standardized mortality ratios (SMRs) and 95% confidence intervals (95% CIs) with the population of Cluj used as standard population. Deaths were classified by cause according to the International Classification of Diseases 10th Revision: cancer, ischemic heart disease, other cardiovascular disease, cerebrovascular disease, accident, gastrointestinal disease, respiratory disease and other disease. Occupational classes were defined according to the British Classification of the Social Classes that divide the occupations in 6 different categories: class I - professional, class II - managers/intermediate, class III(N) - non-manual skilled, class III(M) - manual skilled, class IV - partly skilled, class V - partly unskilled. The data were collected in the Microsoft Excel program and were statistically analysed using the EXCEL and EPIINFO programs. The overall mortality of the social classes I (SMR= 75.41; 95% CI, 67 to 85), II (SMR= 32.91; 95% CI, 25 to 43), III(M) (SMR= 48.22; 95% CI, 43 to 54), and III(N) (SMR= 77.01; 95% CI, 68 to 87) was significantly lower than expected, while for the social classes IV (SMR= 244.81; 95% CI, 217 to 277) and V (SMR= 318.16; 95% CI, 268 to 375) the overall mortality was significantly higher. In particular, for specific causes of death, significant mortality deficits were reported for accidents (SMR= 27.92; 95% CI, 13 to 59 - in class I; SMR= 27.92; 95% CI, 13 to 59 - in class II; SMR= 60.08; 95% CI, 38 to 94 - in class III(M); SMR= 42.78; 95% CI, 23 to 79 - in class III(N); other disease (SMR= 62.58; 95% CI, 42 to 95 - in class I; SMR= 34.47; 95% CI, 16 to 78 - in class II; SMR= 57.86; 95% CI, 41 to 81 - in class III(M); other cardiovascular disease (SMR= 59.27; 95% CI, 42 to 83 - in class I; SMR= 38.44; 95% CI, 21 to 72 - in class II; SMR= 58.43; 95% CI, 45 to 76 - in class III(M); SMR= 64.74; 95% CI, 47 to 90 - in class III(N); gastrointestinal disease (SMR= 18.86; 95% CI, 5 to 64), respiratory disease (SMR= 27.64; 95% CI, 13 to 60), cerebrovascular disease (SMR= 40.22; 95% CI, 29 to 55), cancer (SMR= 53.83; 95% CI, 43 to 68), ischemic heart disease (SMR= 38.89; 95% CI, 30 to 50) - in class III(M). No any cause of death showed significant increase among the social classes I, II, III(M) and III(N). The social classes IV and V showed an elevated mortality from all causes of death. Our results confirm the international studies regarding the socioeconomic inequalities in mortality, with a higher mortality among those of lower social status, with a lower educational level, a lower income level or a low position in the labour market.