Benzo 2011.

Study characteristics
Methods	2 randomised controlled trials Setting: USA (University of Pittsburgh and Mayo Clinic) Study duration Study 1: 18 months. Exercise training for 4 weeks Study 2: 1 year. Exercise training for 1 week
Participants	Participants undergoing lung cancer resection by open thoracotomy (segmentectomy, lobectomy or pneumonectomy) or by VATS (at least lobectomy), with moderate‐to‐severe chronic obstructive pulmonary disease. Study 1: 9 participants randomised in 18 months from a large surgical practice (5 hospitals: academic (3) and community (2)). Study 2: 19 participants (mean age: control group: 72 (SD 7) years: exercise group: 70 (SD 9) years) were randomised in 1 year from 1 site (Mayo Clinic). 2 were considered inoperable and therefore, postoperative data were missing.
Interventions	Study 1 Control (4 participants): usual care, details not reported. Exercise (5 participants): 4 weeks of preoperative pulmonary rehabilitation that followed American Thoracic Society/ European Respiratory Society guidelines on exercise prescription (details on exercise training programme not reported). Study 2 Control (9 participants): usual care, details not reported. Exercise (10 participants): twice‐daily, 10‐session preoperative pulmonary rehabilitation that included 20 minutes of lower extremity endurance training on a treadmill, upper extremity endurance training on an arm ergometer, strengthening exercises for upper and lower limbs with Thera‐band (every second day), 15–10 minutes of inspiratory muscle training, 10 minutes of pursed‐lip breathing and prescription of weekend exercises based on their performance during the pulmonary rehabilitation programme.
Outcomes	Both studies Hospital length of stay Postoperative pulmonary complications (defined as pneumonia (new infiltrate + either fever (> 38.5 °C) and white cell count > 11,000/mm3, or fever and purulent secretions), severe atelectasis (requiring bronchoscopy), prolonged chest tubes (> 7 days), and prolonged mechanical ventilation (> 24 hours))
Notes	Study 1 had poor recruitment (providers were unwilling to delay the curative surgery for 4 weeks) and was stopped, due to low likelihood of meaningful accrual during the funding period. Therefore, only data from study 2 were extracted for this systematic review.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Comment: insufficient information to permit judgement.
Allocation concealment (selection bias)	Unclear risk	Comment: insufficient information to permit judgement.
Blinding of participants and personnel (performance bias) All outcomes	High risk	Comment: no blinding.
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Quote: "Outcomes were obtained using chart review by a nurse trained in the abstraction of the desired outcomes from the medical records and blinded to the treatment".
Incomplete outcome data (attrition bias) All outcomes	Low risk	Quote: "Two patients (one on each arm) were missing length of stay data; because they were considered inoperable once they were in the operating room and were excluded from the outcome analysis". Comment: missing outcome data balanced in numbers across intervention groups, with similar reasons for missing data across groups.
Selective reporting (reporting bias)	High risk	Quote: "Patients did not improve the shuttle walk test after the short term PR [pulmonary rehabilitation] (P = NS [not significant])". Comment: 1 outcome of interest in the review (exercise capacity) was reported incompletely, so it could not be entered in a meta‐analysis.
Other bias	High risk	Comment: study 1 ceased early due to poor recruitment.