A pilot study of respiratory muscle training to improve cough effectiveness and reduce the incidence of pneumonia in acute stroke: study protocol for a randomized controlled trial

Table 1 Sample-size calculation

Expected treatment effect (L/min)	Expected SD within group (L/min)
Expected treatment effect (L/min)	50	100	150	200	250	300
50	15	58	125	250	400	600
100	5	15	35	60	95	125
150	<5	8	15	26	42	58
200	<5	5	10	16	24	34

Estimates of required number of participants per study group to give 80% power at the 5% significance level, according to different expected treatment-effect sizes and different expected group standard deviations (SDs) of the primary outcome (peak expiratory cough flow (PECF) of voluntary cough).

ISSN: 1745-6215