4 Efficacy
This section describes efficacy outcomes from the published literature that the Committee considered as part of the evidence about this procedure. For more detailed information on the evidence, see the overview.
4.1
A randomised controlled trial of 47 patients compared patients with emphysema treated by endobronchial nitinol coils (n=24) against patients who had usual care (n=23; treatment included inhalers, bronchodilators, inhaled steroids and pulmonary rehabilitation). Mean baseline St George's Respiratory Questionnaire scores (scores range from 0 to 100 with lower scores indicating better quality of life) decreased by 8.11 points (from 65.17) in the endobronchial nitinol coil group and increased by 0.25 points (from 53.12) in the usual care group at 3‑month follow‑up (p value between groups=0.04).
4.2
In a case series of 60 patients, mean St George's Respiratory Questionnaire scores decreased by 11.1 points (from 61.5) at 12‑month follow‑up (p<0.05).
4.3
In a case series of 38 patients, median St George's Respiratory Questionnaire scores decreased by 4.2 points (from 63.2) at 1‑year follow‑up (p<0.05). At 2‑year follow‑up, median St George's Respiratory Questionnaire scores decreased from baseline by 8.0 points (p<0.05). At 3‑year follow‑up, median St George's Respiratory Questionnaire scores decreased from baseline by 7.2 points (not significant).
4.4
In the randomised controlled trial of 47 patients with emphysema treated by endobronchial nitinol coils or usual care, mean modified Medical Research Council dyspnoea scores (ranging from 0 to 4, with lower scores indicating decreasing breathlessness) decreased by 0.24 points and 0.09 points respectively, at 3‑month follow‑up (p value between groups not significant). Baseline values were not reported.
4.5
In the case series of 38 patients, median Medical Research Council dyspnoea scores decreased by 0.5 points (from 3.0) at 3‑year follow‑up (p<0.05).
4.6
In a case series of 10 patients, median clinical chronic obstructive pulmonary disease (COPD) questionnaire scores (ranging from 0 to 6, with lower scores indicating decreasing COPD severity) decreased from 3.0 to 2.3 at 6‑month follow‑up (p value not significant).
4.7
In the randomised controlled trial of 47 patients with emphysema treated by endobronchial nitinol coils or usual care, mean baseline forced expiratory volumes in 1 second (FEV1) were 0.72 litres and 0.78 litres respectively. At 3‑month follow‑up, FEV1 increased by 14.19% and 3.57% respectively (p value between groups=0.03).
4.8
In a case series of 16 patients, the mean distance walked in 6 minutes increased by 35.4 metres (from 338 metres), 1 month after an initial endobronchial nitinol coil treatment, and by 69.8 metres 1 month after a second endobronchial nitinol coil treatment (p values<0.05). The mean distance walked in 6 minutes increased from baseline by 84.4 metres 6 months after a final endobronchial nitinol coil treatment (p<0.05).
4.9
Specialist advisers listed key efficacy outcomes as reduction in the frequency of COPD exacerbations, as well as improvements in exercise capacity (for example, 6‑minute walk test), lung function (for example, forced expiratory volume in 1 second, forced vital capacity and residual volume) and quality of life (for example, St George's Respiratory Questionnaire).