A topic in Clinical Evidence summarizes the results of systematic reviews and a number of mostly relatively small RCTs. Several RCTs found that ipratropium improved FEV1 compared to placebo. According to a systematic review (search date 1999) ipratropium improved exercise capacity compared with placebo in 16 of 17 studies. Three RCTs (total n=935) found that tiotropium improved FEV1 compared to placebo at 4 to 13 weeks. One large RCT (n=5887) found that adding ipratropium to a smoking cessation program had no significant impact compared with smoking cessation program alone on decline in FEV1 over 5 years. Two RCTs found that tiotropium reduced exacerbations and hospital admissions compared with placebo (exacerbations per patient per year in the first RCT: 0.76 vs 0.95, p<0.05; hospitalizations 5.5% vs 9.4%, p<0.05) and one found tiotropium more effective than ipratropium (exacerbations 0.73 vs 0.96, p=0.006; quality of life p>0.001).