At baseline , hot flashes contributed most strongly to poor sleep ( correlation coefficient r = -@ , P < @ ) , somatic symptoms such as muscle pains ( r = -@ , P < @ ) , menstrual cycle-resembling complaints ( r = -@ , P < @ ) , anxiety and fears ( r = -@ , P < @ ) , decreased memory and concentration ( r = -@ , P = @ ) , and sexual behavior ( r = -@ , P = @ ) .