Long-term effectiveness of the community-based Complete Health Improvement Program (CHIP) lifestyle intervention: a cohort study

Objective To examine the long-term (three or more years) effectiveness of the volunteer-delivered Complete Health Improvement Program (CHIP) intervention. Design Cohort study. Setting Hawera, New Zealand. Participants Of the total cohort of 284 individuals who self-selected to complete the CHIP lifestyle intervention between 2007 and 2009, 106 (37% of the original cohort, mean age=64.97.4years, range 42-87years; 35% males, 65% female) returned in 2012 for a complimentary follow-up health assessment (mean follow-up duration=49.2+10.4months). Intervention 30-day lifestyle modification programme (diet, physical activity, substance use and stress management) delivered by volunteers in a community setting. Main outcome measures Changes in body mass index (BMI), systolic blood pressure (SBP) and diastolic blood pressure (DBP), fasting plasma glucose (FPG), total cholesterol (TC), low-density lipoprotein (LDL), high-density lipoprotein (HDL) and triglycerides (TG). Results After approximately 4years, participants with elevated biometrics at programme entry maintained significantly lowered BMI (-3.2%; 34.8 +/- 5.4 vs 33.7 +/- 5.3kg/m(2), p=0.02), DBP (-9.4%; 89.1 +/- 4.1 vs 80.8 +/- 12.6mmHg, p=0.005), TC (-5.5%; 6.1 +/- 0.7 vs 5.8 +/- 1.0mmol/L, p=0.04) and TG (-27.5%; 2.4 +/- 0.8 vs 1.7 +/- 0.7mmol/L, p=0.002). SBP, HDL, LDL and FPG were not significantly different from baseline. Participants with elevated baseline biometrics who reported being compliant to the lifestyle principles promoted in the intervention (N=71, 67% of follow-up participants) recorded further reductions in BMI (-4.2%; 34.8 +/- 4.5 vs 33.4 +/- 4.8kg/m(2), p=0.02), DBP (-13.3%; 88.3 +/- 3.2 vs 77.1 +/- 12.1mmHg, p=0.005) and FPG (-10.4%; 7.0 +/- 1.5 vs 6.3 +/- 1.3mmol/L, p=0.02). Conclusions Individuals who returned for follow-up assessment and entered the CHIP lifestyle intervention with elevated risk factors were able to maintain improvements in most biometrics for more than 3years. The results suggest that the community-based CHIP lifestyle intervention can be effective in the longer term, even when delivered by volunteers.