Weller 1980.
| Study characteristics | ||
| Methods | RCT. Design: double‐blind, cross‐over with 2 arms. Duration: 2‐month baseline periods preceding and following 2x 8‐week treatment periods. Location: UK. |
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| Participants | Total participants recruited: n = 29. Diagnosis was confirmed in all by history, examination, and a sweat test. 27 (13 males, 14 females) completed the trial aged 6 to 15 years (mean 10.7 years); of these 27 participants, 22 were chronic sputum producers. Baseline characteristics Age, mean (SD); sputum producers 10.9 (2.1) years, range (6.5 ‐ 15); sputum non‐producers 9.8 (2.8) years range (6.1 ‐ 12.25). FVC % predicted, mean (SD): sputum producers 76% (15.9), range (38 ‐ 101); sputum non‐producers 88% (10.1), range (76 ‐ 104). PEFR % predicted, mean (SD): sputum producers 80% (21.5), range (27 ‐ 113); sputum non‐producers 96% (11.6), range (78 ‐ 107). |
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| Interventions | No reported pretreatment. Group 1: 3 mL sodium‐2‐mercaptoethane sulphonate (Mistabron) 20% 2x daily after physiotherapy. Group 2: 3 mL HS 7% 2x daily after physiotherapy. Inhalations via a Wright nebuliser operated by an air compressor (Aerolyser Electric Inhaler, Aerosol Products (Colchester) Ltd) producing a flow of 8 L/min. |
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| Outcomes | PEFR, FVC, V max 50% VC, RV/TLC. Diary card to record sputum volume, sputum colour, and cough frequency. At monthly clinic visits: sputum cultures, pulmonary function tests (PEFR, FVC, Vmax50%VC, RV/TLC). At beginning and end of trial: CXRs(Chrispin Norman score), full blood count, liver function tests and plasma electrolytes including creatinine. |
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| Notes | Participants divided into sputum producers and non‐sputum producers. Sample size calculation not undertaken. |
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| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Random sequence generation (selection bias) | Unclear risk | Stated that order of treatment was randomised, but no details given as to randomisation process. |
| Allocation concealment (selection bias) | Unclear risk | No detail provided. |
| Blinding of participants and personnel (performance bias) All outcomes | High risk | Described as double‐blind, but participants could discern difference in taste of interventions. |
| Blinding of outcome assessment (detection bias) All outcomes | Unclear risk | Described as double‐blind, but not clear whether outcome assessors were one of the parties blinded. |
| Incomplete outcome data (attrition bias) All outcomes | Low risk | Clear description of dropouts and withdrawals (see below) but it was not stated if an ITT analysis had been performed. 2 participants withdrawn from trial: 1 due to an acute exacerbation during the second treatment period (saline inhalations) for which she received other inhalational treatment (antibiotics and bronchodilators); and 1 did not take her inhalations correctly and was admitted to hospital early in the trial, during saline therapy, both for more intensive medical treatment and for psychiatric reasons (also received other inhalational treatment). |
| Selective reporting (reporting bias) | Low risk | All outcomes stated in the methods were described in the results. |
| Other bias | Low risk | Washout period: 2‐month baseline periods preceding and following 2x 8‐week treatment periods. Sample size calculation not undertaken. |
BD: bronchodilator BMI: body mass index CF: cystic fibrosis CFQ‐R: Cystic Fibrosis Questionnaire ‐ Revised CFTR: cystic fibrosis transmembrane conductance regulator CFU: colony forming units CXR: chest x‐ray FEF25%-75%: mid‐peak expiratory flow FEV1: forced expiratory volume at 1 second FEV0.75: forced expiratory volume at 0.75 seconds FiO2: fraction of inspired oxygen FVC: forced vital capacity HA: hyaluronic acid HS: hypertonic saline IS: isotonic saline ITT: intention‐to‐treat LCI: lung clearance index LCI2-5: number of lung volume (functional residual capacity) turnovers needed to clear the tracer gas to one‐fortieth of the starting concentration MCC: mucociliary clearance MDI: metered dose inhaler MRI: magnetic resonance imaging N2: nitrogen NaCl: sodium chloride PEFR: peak expiratory flow rate PFT: pulmonary function test QOL: quality of life rhDNase: deoxyribonuclease RV: residual volume SEM: standard error of the mean SF6: sulfur hexafluoride TLC: total lung capacity VAS: visual analogue scale VC: vital capacity