Review of review-level evidence to inform the development of NICE public health guidance for the prevention of pre-diabetes among adults in high-risk groups more

[Excerpt from the executive summary]

1.1 Introduction
This report presents the findings of a systematic review of review-level evidence concerning the prevention of pre-diabetes (raised and impaired glucose levels) in populations/groups at higher risk (black and minority ethnic [BME] or low socioeconomic status [SES]) using community- and population-level interventions.

The primary research question for the review was:
What is known from review-level evidence about the effectiveness and cost-effectiveness of population- and community-level interventions to improve modifiable risk factors associated with pre-diabetes and type 2 diabetes among BME and low-income / low-SES groups?

The secondary research questions were:
What is known about promising ways to tailor interventions for diabetes risk factors to BME or low-income groups, for outcomes including improved BMI, physical activity levels, and blood pressure?
What are the barriers/facilitators to the effectiveness of interventions?

1.2 Methods
To locate evidence, a range of databases and websites indexing relevant literature were searched. Review reports were included if they:
1. were related to diabetes or pre-diabetes, obesity, healthy eating or dietary behaviour relevant to diabetes, or physical activity. Studies containing populations that already had diabetes were excluded;
2. were reviews of literature;
3. were published in 1999 or later;
4. were published in English;
5. included studies of adults (18-74 years);
6. included evaluations of interventions using any design (e.g. RCT, comparative trial, one-group);
7. had a focus on population- or community-level interventions; and
8. had a focus on either (i) low-SES or disadvantaged groups or (ii) any BME group relevant to the UK.

The quality of included reviews was assessed and data were extracted using adaptations of the standard tools for NICE public health evidence reviews of reviews.