Assessment of cognitive function in elderly patients with hip fractures

Sammanfattning: Impaired cognitive function is common among elderly patients. The aim of this thesis was to illuminate the documentation of cognitive function in elderly patients with hip fractures and to study the effect of cognitive function on the outcome in this patient group. The Short Portable Mental State Questionnaire (SPMSQ) was used to assess the patients cognitive function in all four papers included in this thesis. In Paper I the nurses documentation of their assessment of the patients cognitive function in their nursing records was compared with the assessment of cognitive function according to the SPMSQ. The nurses assessment of cognitive function was lacking for 12% of the patients. In 24% of the cases this assessment was not in accordance with the SPMSQ results. In the majority of the cases the nurses had assessed the patients as having normal cognitive function despite the fact that they had impaired cognitive function according to the SPMSQ. In Paper II we analyzed the frequency of pressure ulcers in relation to the patients cognitive status according to the SPMSQ. In addition, we also investigated to what extent this information was passed on to the next caregiver. The incidence of pressure ulcers was increased in patients with severe cognitive dysfunction compared to all others, 23% and 14%, respectively. Information concerning the presence of pressure ulcers in the nurses report to the next caregiver was lacking for 42% of the patients with such ulcers. Paper III examined the influence of cognitive function on the outcome after a hip fracture. Patients with severe cognitive dysfunction had a significantly worse outcome compared to other patients with regard to mortality, walking ability, ADL function and the health-related quality of life one year after the fracture. Paper IV focused on predictors of mortality among elderly patients with hip fractures. In a consecutive series of 1944 patients with hip fractures, 45% had an intact cognitive function, 32% a mild or moderate cognitive impairment and 24% a severe cognitive impairment according to the SPMSQ. Mortality during hospitalization amounted to 4%, to 16% at 4 months and to 38% at 24 months. The analyses showed that the combination of an assessment of cognitive function according to the SPMSQ and an assessment of physical health according to the ASA (American Society of Anesthesiologists) could effectively identify patients at risk for increased mortality. In conclusion, the results of this thesis showed that, in elderly patients with hip fractures, the patient s cognitive function has a major impact on the outcome in terms of developing pressure ulcers, post-fracture walking ability, ADL function, and mortality. The assessment of cognitive function can be improved by using a validated assessment tool and our results indicate that the SPMSQ is a suitable instrument for this purpose. The combined use of the ASA classification for assessing physical health and the SPMSQ for assessing cognitive function could effectively identify hip fracture patients at risk for increased mortality and thereby also make it possible to take measures to improve their outcome.