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. 2018 Apr 10;2018(4):CD009877. doi: 10.1002/14651858.CD009877.pub2

Summary of findings 3. Progressive computer glasses with intermediate distance focus versus monofocal computer glasses.

Progressive computer glasses plus intermediate focus compared with monofocal computer glasses for asthenopia
Patient or population: computer workers
Settings: workplace
Intervention: progressive computer glasses with intermediate distance focus
Comparison: monofocal computer glasses
Outcomes Illustrative comparative risks* (95% CI) No of participants
 (studies) Quality of the evidence
 (GRADE) Comments
Assumed risk2 Corresponding risk
Monofocal computer glasses Progressive computer glasses
Asthenopia (change from baseline to 12 months)
VAS scale 0 to 100
12 months' follow‐up
The mean asthenopia change score in the control group was 2.51 The mean asthenopia change score in the intervention group was
 1.44 score points higher (6.95 lower to 9.83 higher) 64
 (1) ⊕⊕⊝⊝
 low1 Change scores based on imputed correlation coefficient (0.7). Sensitivity analysis revealed no change
Headache (change from baseline to 12 months)
VAS scale 0 to 100
12 months' follow‐up
The mean headache change score in the control group was −3.42 The mean headache change score in the intervention group was
 10.73 score points higher (2.02 higher to 19.44 higher) 64
 (1) ⊕⊝⊝⊝
 very low3 Change scores based on imputed correlation coefficient (0.7). Sensitivity analysis revealed different results for values of 0 and 0.9
*The basis for the assumed risk (e.g. the median control group risk across studies) is provided in footnotes. The corresponding risk (and its 95% confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI).
 CI: Confidence interval
GRADE Working Group grades of evidence
 High quality: further research is very unlikely to change our confidence in the estimate of effect.
 Moderate quality: further research is likely to have an important impact on our confidence in the estimate of effect and may change the estimate.
 Low quality: further research is very likely to have an important impact on our confidence in the estimate of effect and is likely to change the estimate.
 Very low quality: we are very uncertain about the estimate.

1 We downgraded the quality of evidence with one level because of risk of bias and with one level because of imprecision (less than 300 participants).

2 This is the mean change score in the control group.

3 We downgraded the quality of evidence with one level because of risk of bias and with one level because of imprecision (less than 300 participants) and with one level again because of inconsistency in the sensitivity analysis.