The impact of increasing intensity of health promotion intervention on risk reduction.

The HealthWise Stepped Intervention Study (1988-1990) at Pacific Gas and Electric was conducted to evaluate how a health promotion program affects behavior change and whether increasing levels of preventive interventions improve health status. The basic intervention components consisted of health risk assessment and health newsletter (Levels 1, 2, 3, and 4). Additional interventions were health resource center and self-care books (Levels 2, 3, and 4), behavioral change workshops and Division Healthwise team (Levels 3 and 4), and case management and environmental policy (Level 4). The study employed a quasi-experimental design with nonequivalent control groups. The overall risk status has significantly improved at all four intervention levels. The comparison across the four intervention levels found that Level 4, combining environmental policy with "high risk" targeting, showed the most impressive performance. Participants in Level 4 consistently showed significantly greater improvement in life-style factors, and their overall risk status also showed the greatest improvement.