References
- Slappendel R, Simpson K, Dubois D, et al. Validation of the PAC-SYM questionnaire for opioid-induced constipation in patients with chronic low back pain. Eur J Pain 2005;10:209-17
- Moulin DE, Iezzi A, Amireh R, et al. Randomised trial of oral morphine for chronic non-cancer pain. Lancet 1996;347:143-7
- Kalso E, Edwards JE, Moore RA, et al. Opioids in chronic non-cancer pain: systematic review of efficacy and safety. Pain 2004;112:372-80
- Meissner W, Leyendecker P, Mueller-Lissner S, et al. A randomised controlled trial with prolonged-release oral oxycodone and naloxone to prevent and reverse opioid-induced constipation. Eur J Pain 2009;13:56-64
- Lewis SJ, Heaton KW. Stool form scale as a useful guide to intestinal transit time. Scand J Gastroenterol 1997;32:920-4
- Leidy NK, Revicki DA, Geneste B. Recommendations for evaluating the validity of quality of life claims for labeling and promotion. Value Health 1999;2:113-27
- Revicki DA, Osoba D, Fairclough D, et al. Recommendations on health-related quality of life research to support labeling and promotional claims in the United States. Qual Life Res 2000;9:887-900
- Rentz AM, Yu R, Muller-Lissner S, et al. Validation of the Bowel Function Index to detect clinically meaningful changes in opioid-induced constipation. J Med Econ 2009;12:371-83
- Frank L, Flynn J, Rothman M. Use of a self-report constipation questionnaire with older adults in long-term care. Gerontologist 2001;41:778-86
- Patrick DL, Burke LB, Powers JH, et al. Patient-reported outcomes to support medical product labeling claims: FDA perspective. Value Health 2007;10(Suppl. 2):S125-37
- Cronbach L. Coefficient alpha and the internal structure of tests. Psychometrika 1951;16:297-334
- Hays RD, Anderson RT, Revicki DA. Assessing reliability and validity of measurement in clinical trials. In: Staquet MJ, Hays RD, Fayers PM, eds. Quality of Life Assessment in Clinical Trials: Methods and Practice. Oxford: Oxford University Press, 1998
- Nunnally JC, Bernstein IH. Psychometric Theory, 3rd edn. New York: McGraw-Hill, 1994
- Cohen J. Statistical Power Analysis for the Behavioral Sciences, 2nd edn. Hillsdale, NJ: Lawrence Erlbaum Associates, 1988
- Hays RD, Revicki DA. Reliability and validity (including responsiveness). In: Fayers P, Hays RD, eds. Assessing Quality of Life in Clinical Trials, 2nd edn. New York: Oxford University Press, 2005:25-39
- Stewart AL, Hays RD, Ware JE. Methods of validating MOS health measures. In: Stewart AL, Ware JE, eds. Measuring Functioning and Well-being: The Medical Outcomes Study Approach. Durham, NC: Duke University Press, 1992