Application of the Clinical Frailty Score and body composition and upper arm strength in haemodialysis patients.

BACKGROUND

To improve outcomes, simple screening tests are required to detect patients at increased risk of mortality. As patients with muscle weakness and wasting are at increased risk of death, we wished to review the use of the Clinical Frailty Score (CFS).

PATIENTS AND METHODS

Dialysis staff graded haemodialysis (HD) patients attending for routine outpatient sessions using the CFS, a functional scoring scale, for patients who require help with their instrumental activities of daily living, classified as clinically frail with scores >4, which were compared with contemporaneous Stoke-Davies comorbidity scores, post-HD body composition measured by bioimpedance, hand grip strength (HGS) and standard laboratory investigations.

RESULTS

The results from 2089 patients (60.2% male) were reviewed, with 890 (42.6%) classified as frail. Frail patients were older [mean ± standard deviation (SD) 71.5 ± 15.6 versus 59.1 ± 15.6 years) and female (50.7% versus 37.3%) and had greater comorbidity {median 2 [interquartile range (IQR) 1-3] versus 1 [0-2]}, body mass index (BMI) (26.0 ± 6.7 versus 25.5 ± 5.4 kg/m),  C-reactive protein (CRP) [8 (IQR 3-20) versus 5 (2-11) mg/L], lower serum albumin (37.6 ± 4.7 versus 40.1 ± 4.7 g/L),  lean BMI (8.9 ± 1.7 versus 9.7 ± 1.6 kg/m) and HGS [13.4 (IQR 9.6-18.8) versus 20.9 (14.5-29) kg] (all P < 0.001). Frailty was independently associated in a multivariable logistic model with age {odds ratio [OR] 2.33 [95% confidence limit (CL) 2.01-2.7]}, body fat mass [OR 1.02 (CL 1.01-1.03)], log CRP [OR 1.63 (CL 1.28-2.07)] (all P < 0.001) and comorbidity [OR 1.45 (CL 1.17-1.8); P = 0.001] and negatively associated with albumin [OR 0.95 (CL 0.92-0.98) and HGS [OR 0.91 (CL 0.9-0.93)] (both P < 0.001).

CONCLUSION

Frail patients are at increased risk of mortality and, as such, simple reliable screening tools are required to rapidly detect patients at risk. The CFS is a useful screening tool that can be readily performed by dialysis staff to identify frail patients. Frailty in HD patients was associated with increasing age, comorbidity, fat weight and inflammation and reduced muscle strength and muscle mass. There is an overlap between frailty and both sarcopenia and protein energy wasting, which requires additional assessments, potentially including body composition, strength, dietary assessments and laboratory investigations. In addition, as the CFS offers a scale, patient trajectories can potentially be serially monitored over time, thus allowing patient-specific interventions or holistic care plans.