Met and unmet demand for hospital beds. Some recent evidence.

Many commentators have noted the interrelation of demand and supply of hospital beds and have suggested that an increase in the supply of hospital beds tends to generate additional demand either in the form of more patients admitted or patients treated for longer periods of time or some combination of the two. We can report that the bed use rate can be predicted more accurately in terms of the five-seventh rule, that is if a National Health Service bed is made available for an additional week, then for five out of seven days it will be occupied. This rule was found to apply at both regional and district level. Variation in admission rates was also investigated and it was found that a large proportion of the observed variation could be explained in terms of one variable--bed supply. In view of the Resource Allocation Working Party's proposals, the relationship between the overall standardized mortality ratio and bed supply, admissions rate and bed use rate was investigated. No significant effect, however, was discovered. In other words, it is bed supply which strongly influences the demand for hospital care and not the overall standardized mortality ratio.