The eight-month trial began in July 1995. A safety culture measure (the Airline Safety Culture Index (ASCI) was used. This had been developed as part of the project and was based on safety climate measures in the research literature. The culture measure and various risk perception measures were completed by control and experimental groups prior to the implementation of the program and again at the conclusion of the trial. Repeated measures ANOVAs were performed. The number of safety hazards reports submitted by each group was also tracked.
On the ASCI, the intervention group’s scores indicated a better safety culture at the start of the trial and further gain over the course of the trial. The control group’s scores got slightly worse over the same period. Repeated measures ANOVAs indicated that the inter-group difference in this outcome over the course of the trial was statistically significant, which the authors interpreted as an indication that the “safety culture improvement in the intervention group was a direct result of the safety program”.
On the measure involving staff perceptions of risk (of common airline hazards), staff rated both the hazardousness of each factor and the likelihood of its occurrence. In each case, the intervention and control groups’ scores were very similar at the start of the trial. At the conclusion of the trial, the intervention group’s perception of hazardousness was lower than that of the control group and the inter-group difference was statistically significant. In the perceived likelihood of hazards occurring, the results were similar with the intervention group’s perceptions changing more than those of the controls.
The authors also reported the number of safety hazard reports submitted in both groups, noting that 48 were submitted in the intervention group and nine in the control group. They list 13 action taken based on identified hazards which arose from the intervention group, and imply that none arose from the control group.
The author concluded that the results suggest that the INDICATE program can increase staff reporting of safety hazards and incidents, improve organizational safety culture, reduce staff perceptions of the severity and likelihood of safety hazards occurring within the airline, and improve staff confidence in how safety is managed. Reviewers had some concerns about the equivalency of the two sites, as there had been no investigation of staff characteristics at each site, and the initial differences in the ASCI scores furthered this concern. On the other hand, they noted that the study had used multiple measures, some of which were objective and all of which were consistent in their direction of change.
Effectiveness of Occupational Health & Safety Management Systems: A Systematic Review