BackgroundWhen medical wards become saturated, the common practice is to resort to outlying patients in another ward until a bed becomes free.ObjectivesCompare the quality of care provided for inpatients who are outlying (O) in inappropriate wards because of lack of vacant beds in appropriate specialty wards to the care given to non outlying (NO) patients.MethodsWe propose a matched-pair cluster study. The exposed group consisted of inpatients that were outliers in inappropriate wards because of lack of available beds. Non-exposed subjects (the control group) were those patients who were hospitalized in the ward that corresponded to the reason for their admission. Each patient of the exposed group was matched to a specific control subject. The principal objective was to prospectively measure differences in the length of hospital stays, the secondary objectives were to assess mortality, rate of re-admission at 28 days, and rate of transfer into intensive care.Results238 were included in the NO group, 245 in the O group. More patients in the O group (86% vs 76%) were transferred into a ward with prescription completed. O patients remained in hospital for 8 days [4-15] vs 7 days [4-13] for NO patients (p = 0.04). 124 (52%) of the NO patients received heparin-based thromboembolic prevention during their stay in hospital vs 104 (42%) of the O patient group (p = 0.03). 66 (27%) O patients were re-admitted to hospital within 28 days vs 40 (17%) NO patients (p = 0.008).ConclusionO patients had a worse prognosis than NO patients.