Background
Methods
Selection criteria
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Participants were adults age 18 years and above
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Must describe an intervention that applies health literacy concepts (compatible with the definition of health literacy as stated earlier [1]), or uses low literacy tools to improve health-related outcomes. We only included articles where health literacy was explicitly stated and a key component in how the intervention was designed
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Intervention target must be same person that the benefits are measured for
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Outcomes must be measured in terms of improvement in three areas, that we broadly summarise as ‘knowledge’, ‘behaviour’ or ‘patient well-being/health’. These are described in much more detail below.
Search strategy
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(randomized controlled trial[Publication Type] OR randomized[Title/Abstract]) AND
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("health-literacy"[All Fields] OR "health-literacy"[MeSH terms])
Study screening and data extraction
Assessment of trial quality
Evidence of efficacy
Demographics of participants and other study aspects
Results
Study characteristics
Demographics of participants and other study aspects
% Who are not the dominant ethnic group within that country
N = 38 | % Low income (<= US $20 k/year)
N = 18 | % With low or inadequate HL
N = 23 | % with < 12 years of eductn or GED
N = 33 | Mean age (yrs)
N = 40 | Gender % F
N = 39 | Latest observation point after intervention start (weeks)
N = 40 | % clearly used a validated HL instrument
N = 40 |
---|---|---|---|---|---|---|---|
57.7 (23–95) | 54.7 (30–76) | 43.3 (23–61) | 36.5 (3–64) | 52 (45–60) | 63.7 (60–77) | 23 (2–26) | 73 |
Methodological characteristics/Trial quality
Random sequence generation (selection bias) | Allocation concealment (selection bias) | Blinding of participants and personnel bias (performance bias) | Blinding of outcome assessment (detection bias) | Incomplete outcome data (attrition bias) | |
---|---|---|---|---|---|
High | 0 % | 15 % | 38 % | 25 % | 33 % |
Unclear | 28 % | 33 % | 40 % | 40 % | 0 % |
Low | 73 % | 53 % | 23 % | 35 % | 68 % |
Selective reporting bias
Study outcomes
Focus of the study | #SS | Knowledge outcomes | #SS | Behavioural outcomes | #SS | Health outcomes |
---|---|---|---|---|---|---|
Medication-related | 4 | 1 1 | 0 | Number of clinically important medication errors [67] | ||
Health-related | 4 | 1 | Glucose-self-monitoring [45] | 0 1 | Viral load (HIV) [31] | |
1 | ||||||
1 | Breast cancer knowledge [24] | 0 | Increase in discussion about screening decisions [41] | 0 | ||
1 | Sterilisation knowledge [30] | 0 | ||||
1 | Hypertension knowledge [34] | 0 | ||||
1 | Recognition of heart attack symptoms [71] | 1 | Improved inhaler technique (COPD) [72] | |||
0 | 1 | Creation of self-management plan for asthma [73] | 1 | Asthma-impact on quality of life indicators [73] | ||
0 | Recognition of stroke symptoms [71] | 3 | 0 | Improvement in LDL-cholesterol [36] | ||
Mental health related | 4 | 5 | 1 0 | |||
2 | ||||||
Behaviour/lifestyle-related | 1 | 3 | ||||
1 | Understanding labels [29] | 2 | 1 | Weight loss [28] | ||
0 | Recall of healthy lifestyle advice [65] | 0 | Attempts to comply with multifactor health lifestyle advice [65] | 0 | Folate B12 and homocysteine concentration in blood [48] | |
0 | Reduced smoking [28] | |||||
0 | Reduced alcohol consumption [32] | |||||
0 | Appointment keeping [63] | |||||
1 | Home safety actions [46] |
Evidence of efficacy
Area | None | 1 outcome | 2 outcomes | 3 outcomes | Totals |
---|---|---|---|---|---|
Knowledge | 42.5 % | 32.5 % | 12.5 % | 12.5 % | 100 % |
Behaviour | 67.5 % | 15 % | 10 % | 7.5 % | 100 % |
Health | 92.5 % | 5 % | 2.5 % | 0 % | 100 % |
Follow-up analyses
Discussion
“…simply represent wasted effort because the questions they ask and the comparisons and outcomes they choose to study are clinically irrelevant. Looking at the many thousands of clinical trials launched annually, this irrelevance may be actually the biggest source of waste in randomized controlled trials…”