The validity and reliability of this questionnaire was reported by Ferrans and Powers in 1985 and 1992 [27,28]. This questionnaire was translated into Persian by Rambod and its validity and reliability have been confirmed [3]. The possible range for the final scores is the same for all four subscales and for the overall (total) score. Total scores may be classified in three levels: desirable (score: 20 - 30), relatively desirable (score: 10 - 19) and unfavorable (score: 0 - 9).