Experimental design:
People referred for pulmonary rehabilitation in two centres will be offer to participate in the study. Those people who will agree to participate and give their formal consent will be asked to answer two questionnaires about urinary incontinence symptoms (see outcomes) to assess the prevalence and the type of these symptoms.
They will subsequently participate in their usual pulmonary rehabilitation program consisting in 90min sessions (including endurance training, muscle strengthening and self-management), 3x/week for 8weeks (centre 1) or 2x60min sessions (including the same components), 3x/week for 8weeks (centre 2).
The effects of the pulmonary rehabilitation program on usual clinical outcomes (according to each centre routine practice; tests may differ between centres) will be compared between those people with or without urinary incontinence symptoms.
As no prevalence data about urinary incontience was available at the time of study design, we planned to recruit the first 100 participants within the first year and to update the sample size calculation based on these preliminary data.
Among the 70 people actually included, 21 (30%) experienced urinary incontinence. Therefore, assuming a true prevalence of 30% in this population and a total width for the 95% confidence interval of 10%, we planned to recruit a total 341 participants.
The ethical approval to recruit this updated number of participants and to increase the duration of recruitment accordingly was obtained.