A systematic Delirium Abatement Program (DAP) (16
) for new admissions to PACs did not shorten the duration of delirium. DAP facility nurses detected substantially more delirium than usual care nurses, and subsequent paperwork for which the facilities received incentive payments was completed in a high proportion of participants in whom delirium was detected. However, other delirium management practices for which the facilities did not receive incentives, such as nurses contacting physicians about delirium, were not performed at a higher rate at DAP sites than at usual care sites. We believe that it was this failure of the DAP facility staff to execute key steps in the intervention that explains our negative results.
Our trial should be interpreted in the context of other reported delirium interventions and the current U.S. skilled nursing facility environment. In 1999, Inouye and colleagues reported that the Hospital Elder Life Program successfully prevented incident delirium in hospitalized elders admitted to the general medical service (40% risk reduction). (10
) This study employed Elder Life specialists funded by the study to carry out the intervention and achieved very high 87% adherence. Subsequently, we demonstrated that proactive geriatrics consultation reduced the incidence of delirium among elderly hip fracture patients (36% risk reduction). (11
) Our study also had very high adherence (77%) with consultant’s recommendations. Neither of these interventions had an effect on the duration of delirium once it developed. Studies that have specifically attempted to reduce the duration of established delirium have been less successful. Cole et al. found that a specialized consultation service did not reduce the duration of delirium. (31
) Notably, adherence to consultant’s recommendations was lower than in the 2 successful delirium prevention trials.
More recently, two interventions performed outside of the U.S. successfully shortened the duration of delirium. Lundstrom and colleagues, in Sweden, demonstrated that care on a specialized ward shortened the duration of delirium among elderly general medicine patients. (32
) The intervention ward employed many of the same components as the DAP, but also involved a complete reorganization of nursing care. The mean length of stay in this study (in excess of 10 days) far exceeds that in U.S. hospitals. Kalisvaart and colleagues, in the Netherlands, found that 3 days of low-dose haloperidol, given prophylactically to high-risk hip surgery patients, shortened the duration of delirium. (33
) Interestingly, both of these interventions began before delirium developed. Currently, there is no successful model shortening the duration of established delirium.
Seeking “real world” relevance, we did not select specialized, high quality facilities for our study. For-profit companies managed all eight facilities, and six of the eight had for-profit ownership. The average state inspection deficiency score for participating facilities was comparable to the overall state average. (17
) Typical of skilled nursing facilities, our sites were plagued with staff turnover, understaffing, and use of agency personnel. (34
) Moreover, all but one site underwent turnover of key administrative leadership during our trial. Lack of stable facility leadership and nursing personnel made adoption of the DAP more challenging. Exit interviews conducted with nurses suggested that insufficient staffing and lack of continuity-of-care reduced adherence. (36
) Analysis of our data suggests that incentive payments may have driven the modest behavioral change seen the trial.
Our trial has several important strengths. First, we screened nearly 5000 new PAC admissions with detailed mental status assessments, and our final sample of 457 represents the largest cohort of delirious patients ever enrolled in a research study. Second, our initial screening and outcome assessments were based on valid and highly reliable delirium assessments and outcomes were assessed blinded to intervention status. Third, though the cohort was enrolled in the PAC setting, participants were interviewed at follow-up regardless of setting. Finally, the DAP intervention was developed using published “best practices” for the detection and management of delirium (12
) and our team included the developers of the federally-mandated long term care resident assessment instrument. (15
Our results should be interpreted in light of several limitations. Given the nature of the DAP, we felt that cluster randomization was the only feasible allocation approach. While this led to a baseline imbalance in several variables, including pre-illness dementia, adjusting for or stratifying by these variables did not alter the study results. The clustering effect also widened the confidence intervals around the intervention effect (), but it is unlikely that increased sample size or improved statistical power would have altered our primary findings. While the DAP was intended to be implemented as a quality improvement intervention on a facility-wide basis, we were only able to ascertain adherence and outcomes in trial participants whose proxies provided informed consent to allow us to review medical records. We also only assessed outcomes at two weeks and one month and therefore may have missed fluctuations in delirium status between these time points.
Finally, and most importantly, we cannot determine whether the DAP would have shortened delirium had research-funded staff directly carried out all intervention steps. We carefully considered this approach when designing the trial, but rejected it because it would have been exceedingly logistically difficult and resource intensive to integrate research staff into clinical nursing practice at four DAP facilities. Our results demonstrate lack of effectiveness using skilled nursing facility-based staff working under current realities. However, our trial does not address the “proof of principle” question of whether the natural history of delirium in PAC can be altered by a systematic multi-component intervention.
In conclusion, our large, rigorously performed cluster randomized controlled trial demonstrated that the DAP did not shorten the duration of delirium in newly admitted PAC patients. Yet, the high prevalence, persistence and morbidity of delirium in PAC compel us to continue to design and test intervention strategies to improve the outcomes of these vulnerable patients. Our trial demonstrates that these strategies should be tested under carefully controlled conditions ensuring implementation of key intervention steps. The results of such a trial would tell us definitively whether the trajectory of patients admitted to PAC with delirium can be altered for the better.