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Database of Abstracts of Reviews of Effects (DARE): Quality-assessed Reviews [Internet]. York (UK): Centre for Reviews and Dissemination (UK); 1995-.

Database of Abstracts of Reviews of Effects (DARE): Quality-assessed Reviews [Internet].

Is the Global Solar UV Index an effective instrument for promoting sun protection? A systematic review

N Italia and EA Rehfuess.

Review published: 2012.

CRD summary

This review concluded that the Ultraviolet Index as implemented had not been successful at improving sun protection practices and reducing sun exposure among the population at large. These conclusions were based on an assessment of the evidence base located through extensive searches and despite some methodological shortcomings are likely to be reliable.

Authors' objectives

To evaluate the effectiveness of the Global Solar Ultraviolet Index as a health promotion instrument.


More than 12 key sources were searched including PubMed, EMBASE and public health databases. This was supplemented by extensive searching of the grey literature, reference checking and contact with experts in the area. English was the main search language but publications in other languages were not excluded. Search terms were reported and covered publications from 1995 onward (when the Ultraviolet Index was introduced).

Study selection

Randomised controlled trials, non-randomised comparative studies, case-control studies, cohort studies and cross-sectional studies were eligible for inclusion. Studies were required to have implemented an intervention (defined in the paper) relating to ultraviolet light exposure including use of the Ultraviolet Index or to have examined familiarity with the Ultraviolet Index. The impact of the Ultraviolet Index on any of the outcomes of familiarity, knowledge, attitude, behaviour or sun exposure (example outcome measures provided) was considered.

Nearly half of the included studies were from countries with high skin cancer rates. Studies were in Europe, Australia, New Zealand, Finland, Sweden and the Americas. One study focused on children (five to 12 years) and 24 studies were concerned with adults (participant ages ranged from 14 years to 79 years; mean values not reported). Around three-quarters of the included studies evaluated a media intervention; the others looked at general or personalised programme materials. Two studies used ultraviolet meters. The outcome of sun exposure was most commonly measured by self-report (questionnaires, on-line surveys or telephone surveys).

One reviewer assessed studies for inclusion.

Assessment of study quality

Two reviewers independently assessed study quality using a published tool with eight components (selection bias, study design, confounders, blinding, data collection methods, withdrawals and drop-outs, intervention integrity and analyses) resulting in an overall rating of weak, moderate or strong evidence. Discrepancies were resolved through discussion.

Data extraction

Two reviewers independently extracted data with any discrepancies resolved through discussion.

Methods of synthesis

A narrative synthesis was used to summarise findings in each of five outcome categories. For very different outcome measures, the reviewers summarised results using the descriptive labels of increase, decrease and no effect; no further details were reported.

Results of the review

Twenty-five studies (28,412 participants) were included: three RCTs, two non-randomised intervention studies and 20 cross-sectional studies. One RCT was rated as strong quality, one as moderate and one as weak. The two non-randomised intervention studies were rated as moderate and weak. Sixteen cross-sectional studies were rated as weak and four were rated as moderate.

Familiarity: Ultraviolet Index awareness (21 studies) varied considerably between countries with very low levels in Germany and Sweden and high levels in some recent Australian studies. Estimates obtained from strong or moderate studies ranged from 27% to 53%. Understanding of the Ultraviolet Index was found to be considerably less prevalent. When only studies rated strong or moderate were considered, estimates ranged from 17% to 55%. Generally, the percentage of the population that claimed to understand the Ultraviolet Index was greater than the percentage who could correctly describe or interpret it.

Knowledge and attitude: Three studies measured self-reported knowledge about ultraviolet radiation and skin cancer. Studies classified as strong or moderate suggested that the Ultraviolet Index had no influence on either outcome.

Behaviour: The impact of the Ultraviolet Index on sun protection behavior was explored by three RCTs and 11 cross-sectional studies. Studies collected data on general sun protection, protective clothing and sunscreen. Strong and moderate studies suggested that the Ultraviolet Index exerted no or only a limited influence on sun protection behaviours. Many people who claimed to use the Ultraviolet Index did not consider it regularly to plan their sun protection.

Sun exposure: Three RCTs and three cross-sectional studies examined sun exposure; one RCT was considered flawed due to use of apparently faulty ultraviolet light meters that gave erroneous readings. Based on strong and moderate studies, the Ultraviolet Index did not appear to influence sun exposure.

Authors' conclusions

The Ultraviolet Index as currently implemented had not been successful at improving sun protection practices and reducing sun exposure among the population at large.

CRD commentary

This review addressed a broad question with reasonably well-defined inclusion criteria and attempted to identify relevant literature through comprehensive searches without language or inappropriate date restrictions. Unpublished studies were included. Most of the review processes were performed in duplicate which helped to minimise reviewer error/bias; study selection was only carried out by one researcher. Study details were presented. A generic quality assessment tool was used which may have obscured differences between study designs; the authors acknowledged this potential shortcoming.

Use of a narrative synthesis appeared appropriate. Reviewers identified shortcomings in several studies – which clearly went beyond classification of quality based on study type alone – and took these flaws into account within the synthesis.

The authors' cautious conclusions appear to reflect the evidence as presented and can be considered reliable.

Implications of the review for practice and research

Practice: The authors recommend that if the Ultraviolet Index was to be more effectively employed: ratings should be part of a regular weather forecast; the value should be part of a safe sun package rather than presented as a standalone figure; and the Ultraviolet Index should be incorporated into comprehensive sun protection programmes.

Research: The authors recommend that well-conducted evaluation studies were needed to explore how the Ultraviolet Index could be used more effectively in the future.


Not reported.

Bibliographic details

Italia N, Rehfuess EA. Is the Global Solar UV Index an effective instrument for promoting sun protection? A systematic review Health Education Research 2012; 27(2): 200-213. [PubMed: 21730253]

Indexing Status

Subject indexing assigned by NLM


Female; Health Knowledge, Attitudes, Practice; Health Promotion; Humans; Male; Reference Values; Skin Neoplasms /prevention & control; Sunlight /adverse effects; Ultraviolet Rays /adverse effects /classification



Database entry date


Record Status

This is a critical abstract of a systematic review that meets the criteria for inclusion on DARE. Each critical abstract contains a brief summary of the review methods, results and conclusions followed by a detailed critical assessment on the reliability of the review and the conclusions drawn.

CRD has determined that this article meets the DARE scientific quality criteria for a systematic review.

Copyright © 2014 University of York.

PMID: 21730253

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