Minimal important difference for London Chest Activity of Daily Living scale in patients with chronic obstructive pulmonary disease

Objectives

To determine the minimal important difference (MID) for the London Chest Activity of Daily Living scale (LCADL) in patients with chronic obstructive pulmonary disease (COPD), focusing on the percentage of the total score (LCADL_%total), using an anchor-based method in addition to distribution-based methods.

Design

Non-controlled before-and-after study.

Setting

Two outpatient centres.

Participants

Seventy-seven patients with COPD (GOLD II–IV, 47 males, forced expiratory volume in 1 second mean 37 (SD 14) % predicted).

Interventions

Aerobic training and localised training for upper and lower limbs was conducted for 24 sessions, three times per week.

Main outcome measures

The main outcome was LCADL score pre- and post-exercise training. The MID was established using distribution and anchor-based methods. The modified Saint George Respiratory Questionnaire was the anchor for the analysis of sensitivity and specificity of the MID.

Results

The established MIDs ranged from −2.1 to −5.9 points for LCADL_total and from −2 to −6 points for LCADL_%total. The receiver operating characteristic curve indicated a cut-off point of −3 points for LCADL_total (sensitivity 51%, specificity 82%; P = 0.01) and −4 points for LCADL_%total (sensitivity 56%, specificity 82%; P = 0.04).

Conclusions

The present findings suggest −3 points and −4 points as the MIDs for LCADL_total and LCADL_%total, respectively.

Clinical trial registration number

ClinicalTrials.gov NCT03251781.

Minimal important difference for London Chest Activity of Daily Living scale in patients with chronic obstructive pulmonary disease