Impact of the occupational safety and health management system (OSHMS) on the reduction of occupational risks in high-risk construction activities

The construction industry is characterized by high exposure to occupational hazards due to the coexistence of critical tasks, changing operational conditions, and frequent deficiencies in preventive management, all of which increase the likelihood of accidents and operational losses. In this context, the present study aimed to evaluate the effect of implementing an Occupational Safety and Health Management System (OSHMS) on system compliance, occupational risk reduction, and economic implications in a highly complex hospital construction project executed in Casma, Peru. A quantitative, applied study with a pre-experimental before-and-after design was conducted in three phases: baseline diagnosis, OSHMS implementation under the Plan–Do–Check–Act (PDCA) cycle, and post-implementation evaluation. The baseline was established through document review, field observation, and application of a Hazard Identification, Risk Assessment, and Control (HIRAC) matrix, while the analysis included descriptive statistics, Pearson’s chi-square test, and benefit–cost evaluation. The results showed that overall OSHMS compliance increased from 22.5% to 79.0%, with substantial improvements in procedures for critical tasks, incident investigation, training, and risk control. Likewise, high-risk conditions decreased from 41% to 0%, low-risk conditions increased from 16% to 61%, and minor accidents declined from four to one, with the cumulative frequency rate decreasing from 39.80 to 9.60. Pearson’s chi-square test confirmed significant differences in the distribution of risk levels before and after the intervention (69.319, p < 0.001). In conclusion, OSHMS implementation substantially improved preventive performance, reduced the severity of occupational exposure, and proved to be economically favorable in a high-risk construction environment.