Intensity of a public health intervention in a systematic review: Assessing it

Article type
Authors
Baker P1, Francis D2, Soares J3
1School of Public Health Queensland University of Technology and Epidemiology Central Regional Services Queensland Health, Australia
2Epidemiology Central Regional Services Queensland Health, Australia
3Division of Nutrition, Physical Activity and Obesity, National Center for Chronic Disease Prevention and Health Promotion, Centers for Disease Control and Prevention, USA
Abstract
Background: Intensity of an intervention is not well defined in the public health literature and it may be one explanation for differences that exist in the outcomes between public health studies.

Objectives: The aim of this study was to describe the approach used in a recent review about community wide interventions for increasing physical activity to categorise the intensity of interventions to assess whether this could help explain differences that existed in the outcomes reported.

Methods: A subjective criterion, by which each study was rated by two independent reviewers, was developed. The criteria were based on six characteristics and attributes that we hypothesised would be important. Each characteristic was assessed as 'more intensive’, 'less intensive’ or 'unclear’. It included: 1) development of community partnerships or coalition; 2) levels of intervention; 3) reach of strategies; 4) continuous provision of intervention; 5) cost; and 6) statement of intensity by the authors. The overall assessment of intensity for each study was categorised as 'high’, 'medium, 'low’ or 'unclear’.

Results: The tool was simple to apply. Nine of the 25 studies included in the review were classified as being 'high intensity’, 10 of 'medium intensity’ and six of 'low intensity’. Seven of the 25 studies reported some improved physical activity outcomes and the majority of these (n = 5) were classified as high intensity. Consistency between assessors will be investigated and reported.

Conclusions: Interpretation of the studies in this review was challenging due to the overall poor quality of the included studies, however assessment of intensity is potentially useful for understanding heterogeneity of effectiveness between public health studies. We recommend that intensity of a public health intervention be assessed in reviews of public health interventions where there is likely to be significant difference in the interventions and populations at which they are targeted.