With the aging of the population, the interest in clinical trials concerning frail elderly patients has increased. Evidence-based practice for the elderly patient is difficult because elderly patients, especially the frail, are often excluded from clinical trials. To facilitate the participation of frail elderly patients in clinical trials, investigators should be more aware of possible barriers when setting up research. While conducting a trial entitled 'A randomized controlled trial of geriatric liaison intervention in frail surgical oncology patients' (LIFE) the main problem was low inclusion rates. This was due to: 1) limited physical and cognitive. reserve of frail elderly patients making participation and extra visits to the hospital ...