OBJECTIVES: We undertook a register-based cohort study to evaluate exposure-response relations between cumulative occupational mechanical exposures, and risk of lateral and medial inguinal hernia repair. METHODS: Among all men born in Denmark between 1938 and 1988, we established a cohort comprising those aged 18-65 years of age, who had at least 1 year of full-time employment between 1993 and 2007. Using information from a Job Exposure Matrix based on expert judgement and year-by-year information on Danish International Standard Classification of Occupations codes for each individual since 1993, we established time-varying cumulative estimates of exposure to daily lifting activities and standing/walking. Cumulative exposures for lagged 5-year time windows were expressed in a way that corresponds to the pack-year concept of smoking (ton-years, frequent-heavy-lifting years, and standing-years). First-time inguinal hernia repairs in the period 1998-2008 were identified in the Danish Hernia Database. We used a logistic regression technique equivalent to survival analysis, adjusting for age, socioeconomic status, region of residence and calendar year. RESULTS: Within the cohort of 1 545 987 men, we identified 22 926 lateral, 15 877 medial and 1592 pantaloon or unspecified first-time inguinal hernia repairs. The risk of lateral hernia repair increased with ton-years, frequent-heavy-lifting-years, and standing-years, with ORs of up to around 1.4. The exposures correlated, but standing-years remained as the most robust risk factor after adjustment for lifting exposures. In general, the risk of medial hernia repair was unrelated to the exposures. CONCLUSIONS: Our findings suggest an increased risk of lateral inguinal hernia repair in relation to occupational mechanical exposures and a preventive potential of around 15% of all cases.
OBJECTIVES: We undertook a register-based cohort study to evaluate exposure-response relations between cumulative occupational mechanical exposures, and risk of lateral and medial inguinal hernia repair. METHODS: Among all men born in Denmark between 1938 and 1988, we established a cohort comprising those aged 18-65 years of age, who had at least 1 year of full-time employment between 1993 and 2007. Using information from a Job Exposure Matrix based on expert judgement and year-by-year information on Danish International Standard Classification of Occupations codes for each individual since 1993, we established time-varying cumulative estimates of exposure to daily lifting activities and standing/walking. Cumulative exposures for lagged 5-year time windows were expressed in a way that corresponds to the pack-year concept of smoking (ton-years, frequent-heavy-lifting years, and standing-years). First-time inguinal hernia repairs in the period 1998-2008 were identified in the Danish Hernia Database. We used a logistic regression technique equivalent to survival analysis, adjusting for age, socioeconomic status, region of residence and calendar year. RESULTS: Within the cohort of 1 545 987 men, we identified 22 926 lateral, 15 877 medial and 1592 pantaloon or unspecified first-time inguinal hernia repairs. The risk of lateral hernia repair increased with ton-years, frequent-heavy-lifting-years, and standing-years, with ORs of up to around 1.4. The exposures correlated, but standing-years remained as the most robust risk factor after adjustment for lifting exposures. In general, the risk of medial hernia repair was unrelated to the exposures. CONCLUSIONS: Our findings suggest an increased risk of lateral inguinal hernia repair in relation to occupational mechanical exposures and a preventive potential of around 15% of all cases.
Authors: Brian M Besch; Karen Curtin; Robert Ritch; R Rand Allingham; Barbara M Wirostko Journal: JAMA Ophthalmol Date: 2018-12-01 Impact factor: 7.389