|An evidence synthesis of qualitative and quantitative research on component intervention techniques, effectiveness, cost-effectiveness, equity and acceptability of different versions of health-related lifestyle advisor role in improving health
|Carr SM, Lhussier M, Forster N, Geddes L, Deane K, Pennington M, Visram S, White M, Michie S, Donaldson C, Hildreth A
The authors concluded that there was insufficient evidence to support or refute the use of lifestyle advisors to promote health and improve quality of life. Most of the analyses were based on small numbers of studies and there was limited opportunity to assess the primary outcome. The authors' conclusion reflects the evidence presented and is likely to be reliable.
To evaluate the effectiveness of the health-related lifestyle advisor in improving the health and well-being of individuals and communities in the UK.
The review also explored the influence of intervention components and context on outcomes; analysed the cost-effectiveness of interventions; and reported the impact of the role on lifestyle advisors themselves. These aspects did not form part of this abstract.
Twenty electronic databases, such as MEDLINE, CINAHL, EMBASE, PsycINFO, Applied Social Sciences Index and Abstracts (ASSIA) and the Database of Abstracts of Reviews of Effects (DARE) were searched without language restrictions for published and unpublished literature from inception to September 2008. Search terms were reported. Further studies were sought from the reference lists of relevant studies, handsearching of selected journals, Internet/website sources and through contact with field experts.
Eligible for inclusion were studies that evaluated the role of the health-related lifestyle advisor in developed countries similar to the UK, that targeted adults and involved interventions aimed at improving health (such as physiological, behavioural change, beliefs and knowledge acquisition, health-care use, participation, effects on relatives/carers and adverse outcomes). Interventions were delivered in a paid or voluntary capacity by individuals or peer groups and could include advice communicated by post, online or electronically; and training/support or counselling to patients, communities, or members of the public. Eligible comparators were standard care or other types of lifestyle advisor.
A variety of lifestyle advisor models, delivery settings, target populations and outcomes were included. Interventions addressed chronic care, mental health, breastfeeding, smoking, diet and physical activity, cervical/breast screening and HIV infection prevention. Details on the content, provider, format, setting, intensity and duration of interventions were described in the report. Six studies were conducted in the UK. Two studies reported qualitative and quantitative data (this abstract focused only on the latter).
Two reviewers independently selected studies for inclusion. Discrepancies were resolved by consensus, and by consultation with a third reviewer if necessary.
Assessment of study quality
Quality assessment of quantitative studies was carried out using the Effective Public Health Practice Project, covering selection bias, study design, confounders, blinding, data collection methods, withdrawals and drop-outs, intervention integrity and statistical analysis. A recognised quality assessment tool was applied to the qualitative studies.
Two independent reviewers assessed study quality. Discrepancies were resolved by consensus and by consultation with a third reviewer if necessary.
Data were extracted or calculated to present effect sizes, including odds ratios (OR) and relative risks (RR), along with standard deviations (SD) and 95% confidence intervals (CI).
Data were extracted by one reviewer and checked by a second reviewer. Discrepancies were resolved by consensus, and by consultation with a third reviewer if necessary.
Methods of synthesis
A narrative synthesis was presented, structured by intervention focus.
Results of the review
Twenty-six studies (25,482 participants) were included. There were 22 randomised controlled trials (RCTs; 23,775 participants; sample size range 130 to 14,080); two controlled before and after studies (1,638 participants); and two studies that reported quantitative and qualitative data (69 participants). Sixteen studies were described as strong quality (14 RCTs; and the two mixed method studies) and 10 studies were described a moderate quality (eight RCTs; two controlled before and after studies).
Overall, evidence was variable. Sixteen quantitative studies reported a significant change in the primary outcome as a result of the health-related lifestyle advisor intervention. There was limited support for impact of lifestyle advisors on health knowledge, behaviours and outcomes. Intervention acceptability was high.
Chronic care (eight studies): None of the five studies that measured general health and quality of life showed any effect. Three studies showed increases in self efficacy, and three studies reported small reductions in overall blood sugar level (HbA1c)
Smoking (four studies): Three studies showed increased rates of smoking cessation. None of the studies measured general health or quality of life.
Breastfeeding (two studies): Both studies reported increased rates of breastfeeding and high levels of satisfaction with the intervention (although one study indicated the importance of appropriately trained peer counsellors). One study showed a decreased rate of diarrhoea in the baby's first three months. Neither study measured general health or quality of life.
Mental health (one study): Decreased levels of anxiety were reported. There was no significant effect on symptoms of depression.
Screening (four studies): Three studies showed increased rates of breast screening attendance. One study reported increased cervical screening attendance. Two studies reported increased knowledge of screening, and one study observed a reduction in barriers to screening. None of the studies measured general health or quality of life.
Diet and physical activity (five studies): Three studies showed no difference in physiological measures. One study reported a small significant difference in blood pressure. Three studies assessed physical activity levels; one reported a significant difference in favour of the lifestyle advisor compared with minimal intervention. None of the studies measured general health or quality of life.
HIV infection prevention (two studies): Increased sex- and drug-related behavioural risk reduction was reported in both studies. Neither of the studies measured general health or quality of life.
Further results were presented in the report.
Cost-effective analysis was undertaken. Lifestyle advisors were considered to have been cost-effective in chronic care and smoking cessation; inconclusive for breastfeeding and mental health; and not cost-effective for screening uptake and diet/physical activity. Interventions were cost-effective for HIV prevention, but this was not applicable in a UK context.
There was insufficient evidence to support or refute the use of lifestyle advisors to promote health and improve quality of life.
This review addressed a complex question, and the broadly-defined inclusion criteria resulted in a highly heterogeneous yield of studies. A range of data sources were used to identify relevant studies and efforts were made to minimise publication and language biases. The review process was conducted with sufficient measures to minimise error and bias, and appropriate quality assessment criteria were applied. Most of the analyses were based on small numbers of studies and there was limited opportunity to assess the primary outcome. Therefore, the authors' conclusion reflected the evidence presented and was likely to have been reliable.
Implications of the review for practice and research
Practice: Concluding from the wider review, the authors stated that low cost interventions were recommended. Recognition of the indigenous knowledge base of the lifestyle advisor; training of lifestyle advisors; message tailoring; clearer definitions of target groups, and evidence of characteristics and particular needs was required, with more explicit intervention approaches; and definitions of peer and lay characteristics in particular settings. The measurement of short-, medium- and long-term outcomes was also recommended.
Research: Drawing on the totality of the review, the authors made multiple wide-ranging recommendations for future areas and direction of research, including the conduct of future systematic reviews. This included taking account of needs assessment, broadened population focus and intervention aims, the measurement of outcomes including equity and continued evidence review.
Health Technology Assessment programme; National Institute for Health Research.
Carr SM, Lhussier M, Forster N, Geddes L, Deane K, Pennington M, Visram S, White M, Michie S, Donaldson C, Hildreth A. An evidence synthesis of qualitative and quantitative research on component intervention techniques, effectiveness, cost-effectiveness, equity and acceptability of different versions of health-related lifestyle advisor role in improving health. Health Technology Assessment 2011; 15(9): i-284
Subject indexing assigned by NLM
Chronic Disease /economics /prevention & control; Cost-Benefit Analysis; Counseling /economics /methods; Health Behavior; Health Knowledge, Attitudes, Practice; Health Personnel /economics; Life Style; Primary Prevention /economics /methods; Public Health Practice /economics; Quality of Life; Randomized Controlled Trials as Topic
Database entry date
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.