Abstract: Six studies met the inclusion criteria, including three RCTs, two cluster-RCTs and one ITS. All were conducted in the USA and comprised targeted mass media interventions for people of African descent (four studies), Spanish-language dominant Latino immigrants (one study), and Chinese immigrants (one study). The two latter studies offered the intervention in the participants’ first language (Spanish, Cantonese, or Mandarin). Three interventions targeted towards women only, one pregnant women specifically. We judged all studies as being at unclear risk of bias in at least one domain and three studies as being at high risk of bias in at least one domain. We categorised the findings into three comparisons. The first comparison examined mass media interventions targeted at ethnic minorities versus an equivalent mass media intervention intended for the general population. The one study in this category (255 participants of African decent) found little or no difference in effect on self-reported behavioural change for smoking and only small differences in attitudes to change between participants who were given a culturally specific smoking cessation booklet versus a booklet intended for the general population. We are uncertain about the effect estimates, as assessed by the GRADE methodology (very low quality evidence of effect). No study provided data for indicators of behavioural change or adverse effects. The second comparison assessed targeted mass media interventions versus no intervention. One study (154 participants of African decent) reported effects for our primary outcomes. Participants in the intervention group had access to 12 one-hour live programmes on cable TV and received print material over three months regarding nutrition and physical activity to improve health and weight control. Change in body mass index (BMI) was comparable between groups 12 months after the baseline (low quality evidence). Scores on a food habits (fat behaviours) and total leisure activity scores changed favourably for the intervention group (very low quality evidence). Two other studies exposed entire populations in geographical areas to radio advertisements targeted towards African American communities. Authors presented effects on two of our secondary outcomes, use of health promotion services and project costs. The campaign message was to call smoking quit lines. The outcome was the number of calls received. After one year, one study reported 18 calls per estimated 10,000 targeted smokers from the intervention communities (estimated target population 310,500 persons), compared to 0.2 calls per estimated 10,000 targeted smokers from the control communities (estimated target population 331,400 persons) (moderate quality evidence). The ITS study also reported an increase in the number of calls from the target population during campaigns (low quality evidence). The proportion of African American callers increased in both studies (low to very low quality evidence). No study provided data on knowledge and attitudes for change and adverse effects. Information on costs were sparse. The third comparison assessed targeted mass media interventions versus a mass media intervention plus personalised content. Findings are based on three studies (1361 participants). Participants in these comparison groups received personal feedback. Two of the studies recorded weight changes over time. Neither found significant differences between the groups (low quality evidence). Evidence on behavioural changes, and knowledge and attitudes typically found some effects in favour of receiving personalised content or no significant differences between groups (very low quality evidence). No study provided data on adverse effects. Information on costs were sparse. The available evidence is inadequate for understanding whether mass media interventions targeted toward ethnic minority populations are more effective in changing health behaviours than mass media interventions intended for the population at large. When compared to no intervention, a targeted mass media intervention may increase the number of calls to smoking quit line, but the effect on health behaviours is unclear. These studies could not distinguish the impact of different components, for instance the effect of hearing a message regarding behavioural change, the cultural adaptation to the ethnic minority group, or increase reach to the target group through more appropriate mass media channels. New studies should explore targeted interventions for ethnic minorities with a first language other than the dominant language in their resident country, as well as directly compare targeted versus general population mass media interventions.

Plain-language summary: We found six studies, all from the USA, four of which targeted African Americans and two which targeted Latino or Chinese immigrants. Of the studies, four were experimental (1693 volunteers) and two reported the results of large, targeted campaigns run in whole communities and cities. The evidence is current to August 2016. The available evidence is insufficient to conclude whether targeted mass media interventions for ethnic minority groups are more, less or equally effective in changing health behaviours than general mass media interventions. Only one study compared participants' smoking habits and intentions to quit following the receipt of either a culturally adapted smoking advice booklet or a booklet developed for the general population. They found little or no differences in smoking behaviours between the groups. When compared to no mass media intervention, a targeted mass media intervention may increase the number of calls to smoking quit lines, but the effect on health behaviours is unclear. This conclusion is based on findings from three studies. One study gave participants access to a series of 12 live shows on cable TV with information on how to maintain a healthy weight through diet and physical activity. Compared to women who did not watch the shows, participants reported slightly increased physical activity and some positive changes to their dietary patterns; however, their body weight was no different over time. Two other studies were large-scale targeted campaigns in which smokers were encouraged to call a quit line for smoking cessation advice. The number of telephone calls from the target population increased considerably during the campaign. This review also compared targeted mass media interventions versus mass media interventions with added personal interactions. These findings, based on three studies, were inconclusive. None of the studies reported whether the interventions could have had any adverse effects, such as possible stigmatisation or increased resistance to messages. Further studies directly comparing targeted mass media interventions with general mass media interventions would be useful. Few studies have investigated the effects of targeted mass media interventions for ethnic minority groups who primarily speak a non-dominant language. Our confidence in the evidence of effect on all main outcomes is low to very low. This means that the true effect may be different or substantially different from the results presented in this review. We have moderate confidence in the estimated increase in the number of calls to smoking quit lines.