The Basic VRS-Effect Study: Clinical Trial Outcomes and Cost-Effectiveness of Low Vision Rehabilitation in Portugal
ISRCTN10894889 | Basic VRS-Effect Study | Hernández-Moreno L et al. (2023)
Hernández-Moreno L, Senra H, Marques AP, Perdomo NM, Macedo AF. The Basic VRS-Effect Study: Clinical Trial Outcomes and Cost-Effectiveness of Low Vision Rehabilitation in Portugal. Ophthalmology Therapy, 2023; 12:307–323.
Locations
Conducted in Portugal
Study Period
Not reported
Study Design
Randomized, controlled, parallel-group trial, 1:1 allocation ratio
Study Population
Experimental Group
Control Group
Follow-up Time: 36 weeks
Outcomes
Durability
Not reported.
Vision
Visual Ability
The Change in visual ability at Week 12 (Primary Outcome):
• Immediate intervention group: 0.91 logits (SD = 1.24)
• Delayed intervention: 0.45 logits (SD = 8.88)
• A linear mixed model (LMM) with visual ability as a dependent variable revealed the effect of arm was not statistically significant (p = 0.059)
LMM with VA in the better-seeing eye as a dependent variable:
• Factor time (F (3,69) = 3.63, p<0.017)
• The effects of interaction time * arm (p<0.54)
• Factor arm (p = 0.07) was not statistically significant
LMM for near VA as dependent variable:
• Factor time (F(3,69) = 49.77, p<0.001)
• For interaction time * arm (F(1,69) = 82.61, p<0.001)
• The effect of arm was not statistically significant (p=0.45)
Contrast Sensitivity
No significant changes in contrast sensitivity after intervention.
Critical Print Size
For critical print size as a dependent variable, the main effect time in weeks was statistically
Significant (F(3,53) = 77.82, p<0.001)
Other
Quality of Life (QoL)
EQ-5D-5L Index Change in health-related QoL (EQ-5D-5L) after 12 weeks:
• Immediate intervention group: QALY gain: 0.102 (p = 0.008)
• Delayed intervention: No significant change (p = 0.477)
• The difference: statistically significant (Mann-Whitney U test, Z = - 2.007, p = 0.045).
Quality-Adjusted Life Years (QALYs)
Change in QALY based on near vision after 12 weeks:
• Immediate intervention group: QALY gain: 0.077 (p < 0.001)
• Delayed intervention: QALY gain: -0.008 (p = 0.490)
• The difference: statistically significant (independent t-test, t(36) = 4.611, p<0.001).
Economic Outcomes
Cost of intervention
• Mean cost: €118.79 (SD = 24.37), range: €103.12–€199.27.
Cost-effectiveness (ICER) based on EQ-5D-5L
• 30,421€/QALY (median: 23,054€/QALY); cost-effective at 2× Portugal GDP per capita (€38,862) threshold
Cost-effectiveness (ICER) based on near vision
1186€/QALY, demonstrating high cost-effectiveness.
Immunognicity
Not reported.
Pharmokinetics
Not reported.
Anatomic
Not reported.
Safety
Not reported.
Conclusion
Basic vision rehabilitation significantly improves visual ability, critical print size, and quality of life in patients with vision impairment. The intervention is cost-effective, supporting its inclusion in clinical care pathways.
Risk of Bias Assessment for Primary Outcome
Randomization Process
High risk
Note: No information on randomization method or allocation concealment.
According to Table 1, the socio-demographic characteristics of the participants at baseline look not comparable between the two groups (e.g., female: 43% vs. 63%)
Missing Outcome Data
High risk
Note: Total missingness of about 15% and unbalanced between the two groups (8.7% vs. 21.7%.
.
Selection of the Reported Results
Low risk Note: Registration with protocol
Deviations from Intended Observations
High risk Note: The study is an open-label study. No information on whether deviations arose because of the trial context. In addition, there is no information on whether there is a substantial impact (on the result) of the failure to analyse participants in the group to which they were randomized with a total missingness of about 15%.
Measurement of the Outcome
Some concerns Note: No information on if the assessors were blinded to the intervention. However, it is unlikely that the assessment would be influenced by knowledge of the intervention.
Overall
High risk
Categories: Dry AMD