THE NEW MOBILITY SCORE AS A PREDICTOR OF EARLY INDEPENDENCY IN BASIC MOBILITY AFTER HIP FRACTURE SURGERY

Abstract

Background and Purpose: If hip fracture patients are to return directly to their own home in the community, instead of transfer to a secondary rehabilitation unit or nursing home, the regain of independency in basic mobility is necessary. Therefore a method for an early, quick and valid prediction of short-term rehabilitation outcome is important for ward personnel to adjust and plan expectations and rehabilitation needs for each patient. This study validates the New Mobility Score(1) as a predictor of the postoperative day of independency in basic mobility, functional mobility at discharge and discharge status.

Subjects: Six hundred and one consecutive unselected hip fracture patients admitted to a special hip fracture unit in an orthopaedic ward.

Methods: The New Mobility Score that describes the prefracture functional level was recorded on admission, while functional mobility was evaluated by the Timed ‘Up & Go’ Test. All patients followed a well defined multi-modal fast track rehabilitation program including intensive physiotherapy. The New Mobility Score is a composite score of the patient’s ability to perform: indoor walking, outdoor walking and shopping before the hip fracture, providing a score between zero and three (0: not at all, 1: with help from another person, 2: with an aid, 3: no difficulty) for each function, resulting in a total score from 0 to 9, with nine indicating a high prefracture functional level. The correlations of the New Mobility Score to all outcome parameters and between groups were examined and for those that significantly predicted the individual outcome, the predictive value and likelihood ratios with 95% CI were calculated. Correlations were measured by the Spearman’s rho with a level of significance of 0.05.

Results: The New Mobility Score was assessed on all 601 patients, but only those 436 (73%) admitted from own home were included in analyses. The New Mobility Score was a significant predictor (P< 0.001) for postoperative day of independency in basic mobility (rho=0.422), Timed ‘Up & Go’ Test performances (−0.301) and length of stay (−0.438). A cutoff point of 7 gave the highest negative predictive value (0.95 and 0.91*) and sensitivity (0.91) of the New Mobility Score to patients not achieving independency in basic mobility and to patients not being discharged directly to own home* with a negative likelihood ratio of 0.2.

Discusssion and conclusion: The results suggest that the New Mobility Score is a valid and easily applicable score that provides the ward personal with a predictive value of the short-term potential of independency in functional mobility during admission and discharge status.