Visual analogue scales for interstitial lung disease: a prospective validation study.

Area of Science:

• Pulmonary Medicine
• Clinical Assessment Tools
• Interstitial Lung Disease (ILD)

Background:

• Visual analogue scales (VAS) are widely used for symptom assessment but lack validation in interstitial lung disease (ILD).
• Simple, validated tools are needed for non-specialist clinicians to monitor ILD disease burden.
• Assessing ILD progression and treatment response requires reliable symptom measurement.

Purpose of the Study:

• To validate VAS for assessing changes in dyspnoea, cough, and fatigue in ILD patients.
• To establish the minimal clinically important difference (MCID) for these VAS symptom assessments.
• To provide a tool for remote ILD patient monitoring.

Main Methods:

• 64 ILD patients completed VAS for dyspnoea, cough, and fatigue at baseline and 3-6 months.
• Baseline assessments included King's Brief ILD questionnaire (K-BILD), lung function, and 6-minute walk test (6MWT).
• MCID was determined by analyzing VAS change in patients reporting a 'small but just worthwhile' symptom improvement, validated in a separate cohort.

Main Results:

• VAS demonstrated significant differences between patients reporting symptom change versus no change (P < 0.01).
• MCID estimates: 22.0 mm for VAS Dyspnoea and 14.5 mm for VAS Fatigue.
• VAS Dyspnoea changes correlated significantly with K-BILD, forced vital capacity, and 6MWT, but VAS Cough did not reach significance.

Conclusions:

• VAS is a valid tool for tracking dyspnoea and fatigue changes in ILD patients.
• Established MCID values (22.0 mm for dyspnoea, 14.5 mm for fatigue) provide benchmarks for clinical significance.
• Validated VAS can support ILD management outside specialist centers.