Chen 2015.
| Methods | Randomised, parallel‐group study. | |
| Participants |
N = 85 participants with new SAHS diagnosis. Inclusion criteria: AHI >15, daytime sleepiness, two major symptoms of the syndrome, lived within 100 miles from Zhejiang. Exclusion criteria: previously received CPAP therapy, suffering with COPD, asthma, or neurological problems. Baseline characteristics: 38.3% female. Mean age 50.4 (NR). Mean AHI 54.5. Mean ESS 13. Mean BMI 32.5. Country: China |
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| Interventions | 85 participants were randomised to nurse‐led intensive vs standard support, of which 5 refused to participate (group allocation of refusals not reported), resulting in n = 40 receiving intervention and n = 40 receiving control condition. Intervention: hospital health education, consisting of pre‐treatment 30‐minute educational video that explained the pathogen, mechanism, risks, benefit, and treatment methods for SAHS; personalised guidance from a nurse; and an SAHS Health education Manual. In addition, several patient self‐management interventions were delivered including: 15‐minute interview with nurse for troubleshooting within 5 days of receiving CPAP treatment, nurse home visits after CPAP treatment was initiated, healthy lifestyle (diet, exercise) guidance, and a psychological intervention, informing patients of the importance of maintaining a good mental state for disease rehabilitation, and teaching the patients methods and techniques on how to respond to anxiety and depression. Finally, each participant in the intervention arm received a ˜30‐minute consultation with sleep physician within 1 month of CPAP initiation. Control: ˜30‐minute consultation with sleep physician at 1, 3, 6 and 12 months. Study duration: 12 months. |
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| Outcomes |
The data regarding the usage of CPAP by the patients were recorded and handled with professional software) at each clinical visit. All participants underwent a daytime function testing at the beginning and after 12 months of the initiation of CPAP treatment. Function testing included the following steps: an in‐house questionnaire was given to assess the severity of sleep apnoea symptoms. |
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| Notes | ||
| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Random sequence generation (selection bias) | Low risk | "This study was designed as a randomised, single‐blinded, prospective trial of nurse‐led intensive vs standard support.... The included patients were randomised into two groups via a predetermined balanced block which was generated by tossing a coin: standard support group and intensive support group." |
| Allocation concealment (selection bias) | Unclear risk | No reference to block sizes to or other allocation concealment methods. |
| Blinding (performance bias and detection bias) All outcomes | High risk | No evidence of blinding of personnel or outcome assessors. Study had subjective outcomes, so knowing group assignment could influence these outcomes. Study says that "patients were blinded to the allocation and did not know to which group they were assigned", but did not explain how this was performed or maintained. |
| Incomplete outcome data (attrition bias) All outcomes | Unclear risk | Data available for 80 of 85 (94%) of randomised participants. However, it is not clear to which group these 5 missing participants belonged to ‐ there is the possibility that all 5 came from one group, which would results in 12.5% (5/40) withdrawals. This would not be critical for measuring CPAP adherence (as it is objective and can be predicted to be 0 for those who refuse to participate), but it would be critical for subjective outcomes. |
| Selective reporting (reporting bias) | High risk | No protocol, abstract, clinical trials entry available for comparison. Results presented were not consistent with the plan specified in the Methods section of the publication. |
| Other bias | Low risk | No baseline imbalances or reported deviations from intended intervention. Although there is the issue of the 5 missing participants, this is already covered in the "Incomplete Outcome Data" domain (do not want to double count). |
| Bias arising from the randomisation process (ROB2, primary outcome) | Unclear risk | Regarding the randomisation procedures, authors report: "This study was designed as a randomised, single‐blinded, prospective trial of nurse‐led intensive vs standard support.... The included patients were randomised into two groups via a predetermined balanced block which was generated by tossing a coin: standard support group and intensive support group." No reference to block sizes to or other allocation concealment methods. |
| Bias due to deviations from intended interventions (ROB2, primary outcome) | Unclear risk | Authors report: "Patients were blinded to the allocation and did not know to which group they were assigned." No information was provided as to how blinding was performed/maintained. After randomisation, n = 5 participants 'refused to participate.' No further information was provided, including: group allocation of dropouts, reasons for refusal. This suggests the possibility that the deviation arose because of experimental context/expectation of differences between groups (e.g. disappointment about assignment). mITT used. |
| Bias due to missing outcome data (ROB2, primary outcome) All outcomes | Low risk | Data available for 80 of 85 (94%) of participants. |
| Bias in measurement of the outcome (ROB2, primary outcome) All outcomes | Low risk | Outcome measured using objective CPAP usage data. Each intervention group outcome data ascertained via automated CPAP device monitoring; devices identical or sufficiently similar (i.e. similar distributions of CPAP device make) across groups. Outcome "assessor" is CPAP device: no knowledge of allocation possible. |
| Bias in selection of the reported result (ROB2, primary outcome) All outcomes | Unclear risk | No protocol, abstract, clinical trials entry available for comparison. Results presented were not consistent with the plan specified in the Methods section of the publication. Description of intended outcome measurements (time points) was very limited: "All participants underwent a daytime function testing at the beginning and after 12 months of the initiation of CPAP treatment. Function testing included the following steps: an in‐house questionnaire was given to assess the severity of sleep apnoea symptoms; Epworth and Stanford sleepiness scales were calculated to assess sleepiness; mood was evaluated using the Hospital Anxiety and Depression Scale; and quality of life was measured by the Short Form‐36." This suggests 12‐month CPAP usage is intended primary outcome. Results section (text) for CPAP usage reported: "The average compliance was 2.2 hours (51%) longer among participants in the intensive support group than those in the standard support group; this difference was statistically significant between the two groups (Table 13 and Figure 2)." Authors provide no time point reference for this single outcome value, but based on results table, this corresponds to the 3‐month outcome point. The full results table presents CPAP usage outcome data at 1, 3, 6 and 12 month time points. Taken together, this report suggests there was no pre‐determined outcome assessment plan (particularly with regard to time points). |
| Overall risk of bias (ROB2, primary outcome) Machine usage | High risk | ‐ |