Patient safety, cost-effectiveness, and quality of life: reduction of delirium risk and postoperative cognitive dysfunction after elective procedures in older adults-study protocol for a stepped-wedge cluster randomized trial (PAWEL Study)

Abstract

Background: Postoperative delirium is a common disorder in older adults that is associated with higher morbidity and mortality, prolonged cognitive impairment, development of dementia, higher institutionalization rates, and rising healthcare costs. The probability of delirium after surgery increases with patients' age, with pre-existing cognitive impairment, and with comorbidities, and its diagnosis and treatment is dependent on the knowledge of diagnostic criteria, risk factors, and treatment options of the medical staff. In this study, we will investigate whether a cross-sectoral and multimodal intervention for preventing delirium can reduce the prevalence of delirium and postoperative cognitive decline (POCD) in patients older than 70 years undergoing elective surgery. Additionally, we will analyze whether the intervention is cost-effective.

Methods: The study will be conducted at five medical centers (with two or three surgical departments each) in the southwest of Germany. The study employs a stepped-wedge design with cluster randomization of the medical centers. Measurements are performed at six consecutive points: preadmission, preoperative, and postoperative with daily delirium screening up to day 7 and POCD evaluations at 2, 6, and 12 months after surgery. Recruitment goals are to enroll 1500 patients older than 70 years undergoing elective operative procedures (cardiac, thoracic, vascular, proximal big joints and spine, genitourinary, gastrointestinal, and general elective surgery procedures).

Discussion: Results of the trial should form the basis of future standards for preventing delirium and POCD in surgical wards. Key aims are the improvement of patient safety and quality of life, as well as the reduction of the long-term risk of conversion to dementia. Furthermore, from an economic perspective, we expect benefits and decreased costs for hospitals, patients, and healthcare insurances.

Trial registration: German Clinical Trials Register, DRKS00013311 . Registered on 10 November 2017.

Keywords: Cost-effectiveness; Cross-sectoral care; Delirium prevention; Dementia; Elective surgery; Older patients; Postoperative cognitive dysfunction; Quality of life.

Fig. 1

Timeline and randomization

Fig. 2

Recruitment procedure. PAWEL Patient safety, cost-effectiveness and quality of life: reduction of delirium risk and post-operative cognitive dysfunction after elective procedures in the elderly

Fig. 3

Standard Protocol Items: Recommendations for Interventional Trials figure of enrollment, intervention, and assessments. CSHA Clinical Frailty Scale of the Canadian Study of Health and Aging, EQ-5D-5L EuroQol five dimensions questionnaire, G-ZBI German Zarit Burden interview, I-CAM-S I-Confusion Assessment Method-based scoring system for delirium severity, IQCODE Informant Questionnaire on Cognitive Decline in the Elderly, MNA-SF Mini Nutritional Assessment Short Form, MoCA Montreal-Cognitive Assessment, NOSGER II Nurses’ Observation Scale for Geriatric Patients, NRS Pain Numerical Rating Scale of Pain, NuDESC Nursing Delirium Screening Scale, PHQ-4 Patient Health Questionnaire, PSQI (Basic) Pittsburgh Sleep Quality Index (Basic), RASS Richmond Agitation–Sedation Scale, SF-12 12-Item Short Form Survey, SMI subjective memory impairment, TMT Trail Making Test, V1/V2/V3 parallel versions of the MoCA, STOP BANG Sleep Apnea Questionnaire (snoring, tiredness, observed apnea, blood presure, body mass index, age, neck circunference, gender)