NETT 2003.
| Methods | Randomised controlled trial Method of randomisation: computer‐generated random number sequence Allocation concealment: adequate Outcome assessor blinding: not described | |
| Participants | Screened: 3777
Randomised: 1218 (LVRS 608; control 610)
Mean age in years: 66.6
Emphysema: heterogeneous and homogenous
Diagnosis: CT scan
Entry criteria: FEV1 ≤ 45 % predicted (≥ 15 % predicted among participants ≥ 70 years of age); TLC ≥ 100% predicted; RV ≥ 150% predicted; partial pressure of resting arterial carbon dioxide ≤ 60 mmHg; resting partial pressure of arterial oxygen ≥ 45 mmHg; ability to walk ≥ 140 metres in 6 minutes; ability to complete 3 minutes on a bicycle ergometer; abstinence from smoking for 6 months before randomisation Exclusion criteria: concurrent medical conditions precluding surgery or that might interrupt follow‐up SGRQ total score in units (SD): 52.5 (12.6) for LVRS vs 53.6 (12.7) for control 6MWD in metres (SD): 370.78 (95.28) for LVRS vs 377.55 (96.32) for control FEV1 in % predicted (SD): 26.8 (7.4) for LVRS vs 26.7 (7.0) for control RV in % predicted (SD): 220.5 (49.9) for LVRS vs 223.4 (48.9) for control TLC in % predicted (SD): 128 (15.3) for LVRS vs 128.5 (15.0) for control PaO2 in mmHg: 64.5 for LVRS vs 64.2 for control PaCO2 in mmHg: 43.3 for LVRS vs 43.0 for control DLCO in % predicted: 28.3 for laser vs 28.4 for control |
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| Interventions | LVRS via VATS or MS vs usual medical care according to ATS recommendations Usual care tailored to each participant in the control group included smoking cessation (for those resuming smoking during course of the study); drug therapies (including CS and inhaled bronchodilators); LTOT; immunisations; and continued pulmonary rehabilitation. Pulmonary rehabilitation: 3 phases: prerandomisation (6 to 10 weeks); post randomisation: 8 to 9 weeks) and long‐term maintenance (duration of the trial). PR consisted of physical, educational and psychosocial components (including nutritional counselling). Offered to both treatment groups |
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| Outcomes | Mortality; exercise capacity; quality of life; FEV1; FVC; RV; cost; complications; length of hospital stay | |
| Notes | Funding received by National Heart, Lung and Blood Institute (NHLBI) | |
| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Random sequence generation (selection bias) | Unclear risk | Randomisation mentioned but methods not described |
| Allocation concealment (selection bias) | Unclear risk | Not reported |
| Blinding of participants and personnel (performance bias) All outcomes | High risk | Study is indicated to be unmasked |
| Blinding of outcome assessment (detection bias) All outcomes | Unclear risk | No mention of blinding for outcome assessors |
| Incomplete outcome data (attrition bias) All outcomes | Unclear risk | Methods of handling outcome data missing from questionnaires (if any) not described |
| Selective reporting (reporting bias) | Low risk | Prespecified published protocol is not available for comparison, but rationale behind the trial is published. |
| Other bias | Low risk | No other biases identified |