An effectiveness evaluation of a multifaceted preventive intervention on occupational injuries in foundries: a 13-year follow-up study with interrupted time series analysis

Few intervention studies aimed at preventing occupational injuries (OI) are available, particularly in the foundry sector. Evaluation of effectiveness of an intervention to prevent OI was carried out in two foundries (cast-iron = A, non-ferrous = B).A multifaceted intervention was developed by a team composed of occupational physician, safety personnel and workers' representatives. Intervention focused on safety procedures, education, health surveillance (HS), fitness for work and first aid. Mandatorily registered OI data were collected. Primary outcome was reduction in injury rates. Before-after, pre-peri-post and interrupted time series (ITS) analyses were performed. Secondary outcomes mainly regarded re-injury rates and lost workdays (LW) reduction, access to HS, implementation of good practices and insurance litigation costs.In 1997-2009, 556 and 97 OI occurred in A and B, accounting for 11,597 and 2,567 LW, respectively. A significant (P < 0.01) decrease in OI incidence (-57% in A and -51% in B) and frequency (-56% in A and -46% in B) was shown. ITS analysis displayed a significant (P < 0.01) long-term decreasing trend for incidence (-0.29), frequency (-0.35) and severity (-0.55) rates in foundry B. Upper and lower extremity, eye, hand and head injuries were reduced. HS allowed focused human factor and fitness for work evaluation. Positive changes in safety culture and procedures were obtained.The intervention showed effectiveness in reducing OI rates and in improving quantitative and qualitative outcomes in two representative foundries. Challenges and limitations of interventions to assess effectiveness in preventing OI were evaluated and solutions applied.