Model Predicts Fatigue in Primary Biliary Cirrhosis
Model based on daytime sleepiness and autonomic dysfunction
WEDNESDAY, Feb. 13 (HealthDay News) -- A model based on daytime sleepiness and autonomic dysfunction predicts fatigue in patients with primary biliary cirrhosis, researchers report in the February issue of Clinical Gastroenterology and Hepatology.
Julia L. Newton, M.D., Ph.D., from Newcastle University in the United Kingdom, and colleagues developed a predictive model for fatigue based on daytime hypersomnolence (based on the Epworth Sleepiness Scale or ESS) and autonomic dysfunction (based on the Orthostatic Grading Scale or OGS) using data from 124 patients with primary biliary cirrhosis.
The researchers found that a composite criterion based on both daytime hypersomnolence and autonomic dysfunction had a sensitivity of 0.71 and a specificity of 0.80. The criterion was met by 97 percent of fatigued patients and none of the non-fatigued patients. The study results suggest that there is a threshold effect for fatigue in primary biliary cirrhosis, because having both daytime hypersomnolence and autonomic dysfunction was not associated with more severe fatigue. The predictive value of the model was similar in an independent group of 114 patients.
"A significant proportion of fatigue in primary biliary cirrhosis associates with one or both of autonomic dysfunction (OGS of 4 or greater) and sleep disturbance (ESS of 10 or greater)," Newton and colleagues conclude. "Those meeting both ESS and OGS criteria were not more severely fatigued than those meeting the diagnostic criterion for either alone. A threshold effect for fatigue has implications for potential therapeutic interventions."