A systematic review on the impact of mass media on health services utilisation

Tags: Poster
Grilli R, Freemantle N, Minozzi S, Domenighetti G, Finer D

Introduction/Objective: To review the available evidence on the effect of mass media (radio, TV, newspapers, magazines, leaflets, posters and pamphlets) on health services utilisation.

Methods: Unrestricted systematic literature search of experimental and rigorous quasi experimental (interrupted time series and controlled before-after studies) evaluations, assessing the impact of mass media either on objective measures of use of health services or on related health outcomes. Information on characteristics and content of the interventions was abstracted from original papers, as well as quantitative raw data on patterns of health services utilisation. Standardised regression coefficients representing intervention effect size were calculated for each study using appropriate statistical methods. The direction of intervention effect (eg positive or negative) was also standardised, so that a negative effect size always described a change in use of health services occurring in the intended direction. Effect sizes were then pooled across studies assessing the impact of mass media on similar aspects of care, using a random effects model.

Results: Out of 69 papers providing information on the impact of mass media on aspects of health services utilisation, 17 interrupted time series met our quality criteria. Fourteen evaluated the impact of formal mass media campaigns, 3 of media coverage of health related issues. The overall methodological quality was rather variable. Six studies did not perform any statistical analysis, and 7 used inadequate statistical tests (i.e. not taking into account the effect of time trend). All the studies but one concluded positively on the effect of mass media. These positive findings were confirmed by our re-analysis in 7 studies. Effect sizes were consistent across studies, always pointing toward the expected direction of change. The pooled effect sizes for studies assessing the impact of mass media on similar aspects of care revealed an effect upon the utilization of health services that could not be explained by chance alone, ranging from -1.96 (95%CI: -1.19 to -2.73) for campaigns promoting immunization programs, to -1.12 (95%CI: -0.49 to -2.36) for those concerning cancer screening.

Discussion: Despite the overall limited quality of primary research and its limited informativeness on key aspects of mass media effect, this review found evidence supporting the view that these channels of communication may have an important role in influencing the use of health care interventions. Those engaged in promoting a better uptake of research information in clinical practice should consider mass media as one of the tools that may encourage the use of effective services and discourage those of unproved effectiveness.