Nausea was improved in the PREFER group ( 2.42.7 vs. 1.71.7 , P = 0.02 ) , and total symptom burden , self-efficacy , and quality of life improved by 18 % ( P = 0.035 ) , 17 % ( P = 0.041 ) , and 24 % ( P = 0.047 ) , respectively .