Chronic and persistent pain, which is a problem for the individual who suffers and the society that has to deal with it, has become increasingly appreciated. Over the last three decades, several books and journals have been specifically devoted to the topic of pain, especially chronic and persistent pain. It has been increasingly recognized that chronic and persistent pain, unlike acute pain, involves significant psychosocial factors and requires treatment strategies that deal with these issues. All measurements and factors that affect improvement seem to be in the psychosocial area rather...