Nursing home characteristics and the development of pressure sores and disruptive behaviour.

Objective: To determine how nursing home characteristics affect pressure sores and disruptive behaviour.

Method: Residents (n = 5518, aged > or =60 years) were selected from 70 nursing homes in the National Health Care chain. Homes were classified as high- or low-risk based on incidence tertiles of pressure sores or disruptive behaviour (1989-90). Point-prevalence and cumulative incidence of pressure sores and disruptive behaviour were examined along with other functional and service variables.

Results: The overall incidence of pressure sores was 11.4% and the relative risk was 4.3 times greater in high- than low-risk homes; for disruptive behaviour, the incidence was 27% and the relative risk was 7.1 times greater in the high-risk group. At baseline, fewer subjects in homes with a high risk of pressure sores were white or in restraints, but more had received physician visits monthly and had had problems with transfers and eating. High-risk homes also had fewer beds and used less non-licensed nursing staff time. At follow-up (1987-90), 52% of homes in the low-risk group and 35% of those in the high-risk group had maintained their risk status; low-risk homes were more likely to have rehabilitation and maintenance activities. Having multiple clinical risk factors was associated with more pressure sores in high- (but not low-) risk homes, suggesting a care-burden threshold. By logistic regression, the best predictor of pressure sores was a home's prior (1987-88) incidence status. Interestingly, 67% of homes with a high risk of pressure sores were also high-risk for disruptive behaviour, while only 27% of homes with a low risk of pressure sores were high-risk for disruptive behaviour. A threshold effect was also observed between multiple risk factors and behaviour. More homes with a high risk of disruptive behaviour (68%) remained at risk over 4 years, and the best predictor of outcome was a home's previous morbidity level.

Conclusion: Nursing-home characteristics may have a greater impact than clinical factors on pressure sores and disruptive behaviour in long-stay, institutionalized elders.