FIGURE 1.
Flow diagram indicating patient screening, recruitment, randomisation and follow-up. Missing sleep study data occurred in one cognitive behavioural therapy for insomnia (CBTi) study pre-treatment, and five CBTi and two control studies post-treatment (there were no significant between-group differences in rates of missing sleep study data pre- or post-treatment; both Fisher's exact p>0.05). 71 CBTi and 73 control patients had available sleep study data for mixed model analyses. ISI: insomnia severity index; OSA50: obstructive sleep apnoea 50 questionnaire; AHI: apnoea–hypopnoea index; CPAP: continuous positive airway pressure.