21. Beneciuk JM, Lentz TA, He Y, Wu SS, George SZ. Prediction of persistent
musculoskeletal pain at 12 months: a secondary analysis of the Optimal
Screening for Prediction of Referral and Outcome (OSPRO) validation cohort
study. Phys Ther. 2018;98:290 – 301.
22. Freburger JK, Holmes GM, Agans RP, Jackman AM, Darter JD, Wallace AS, et
al. The rising prevalence of chronic low back pain. Arch Intern Med. 2009;
169:251– 8.
23. Carey TS, Freburger JK, Holmes GM, Jackman A, Knauer S, Wallace A, et al.
Race, care seeking, and utilization for chronic back and neck pain:
population perspectives. J Pain Off J Am Pain Soc. 2010;11:343 – 50.
24. Jensen MP, Turner JA, Romano JM, Fisher LD. Comparative reliability and
validity of chronic pain intensity measures. Pain. 1999;83:157 – 62.
25. Bolton JE. Accuracy of recall of usual pain intensity in back pain patients.
Pain. 1999;83:533 – 9.
26. Childs JD, Piva SR, Fritz JM. Responsiveness of the numeric pain rating scale
in patients with low back pain. Spine. 2005;30:1331 – 4.
27. Vernon H. The neck disability index: state-of-the-art, 1991-2008. J Manip
Physiol Ther. 2008;31:491 – 502.
28. Vernon H, Mior S. The neck disability index: a study of reliability and validity.
J Manip Physiol Ther. 1991;14:409 – 15.
29. Hudson-Cook N, Tomes-Nicholson K, Breen A. A revised Oswestry disability
questionnaire. In: Roland M, Jenner J, editors. Back pain: new approaches to
rehabilitation and education. New York: Manchester University Press; 1989.
p. 187 – 204.
30. Fritz JM, Irrgang JJ. A comparison of a modified Oswestry low back pain
disability questionnaire and the Quebec back pain disability scale. Phys
Ther. 2001;81:776 – 88.
31. Beaton DE, Wright JG, Katz JN, Upper Extremity Collaborative Group.
Development of the QuickDASH: comparison of three item-reduction
approaches. J Bone Joint Surg Am. 2005;87:1038 – 46.
32. Irrgang JJ, Anderson AF, Boland AL, Harner CD, Kurosaka M, Neyret P, et al.
Development and validation of the international knee documentation
committee subjective knee form. Am J Sports Med. 2001;29:600 – 13.
33. Butera KA, Lentz TA, Beneciuk JM, George SZ. Preliminary evaluation of a
modified STarT back screening tool across different musculoskeletal pain
conditions. Phys Ther. 2016;96:1251 – 61.
34. Charlson ME, Pompei P, Ales KL, MacKenzie CR. A new method of classifying
prognostic comorbidity in longitudinal studies: development and validation.
J Chronic Dis. 1987;40:373 – 83.
35. Katz JN, Chang LC, Sangha O, Fossel AH, Bates DW. Can comorbidity be
measured by questionnaire rather than medical record review? Med Care.
1996;34:73– 84.
36. George SZ, Beneciuk JM, Bialosky JE, Lentz TA, Zeppieri G, Pei Q, et al.
Development of a review-of-systems screening tool for orthopaedic
physical therapists: results from the Optimal Screening for Prediction of
Referral and Outcome (OSPRO) cohort. J Orthop Sports Phys Ther. 2015;45:
512– 26.
37. Lentz TA, Beneciuk JM, Bialosky JE, Zeppieri G, Dai Y, Wu SS, et al.
Development of a yellow flag assessment tool for orthopaedic physical
therapists: results from the Optimal Screening for Prediction of Referral and
Outcome (OSPRO) cohort. J Orthop Sports Phys Ther. 2016;46:327 – 43.
38. Beneciuk JM, Fritz JM, George SZ. The STarT back screening tool for
prediction of 6-month clinical outcomes: relevance of change patterns in
outpatient physical therapy settings. J Orthop Sports Phys Ther. 2014;44:
656– 64.
39. Myers RH. Classical and modern regression with applications. 2nd ed. Pacific
Grove: Duxbury Press; 2000.
40. Weuve J, Tchetgen Tchetgen EJ, Glymour MM, Beck TL, Aggarwal NT,
Wilson RS, et al. Accounting for bias due to selective attrition: the example
of smoking and cognitive decline. Epidemiol Camb Mass. 2012;23:119 – 28.
41. Hernán MA, Hernández-Díaz S, Robins JM. A structural approach to
selection bias. Epidemiol Camb Mass. 2004;15:615 – 25.
42. Kent P, Keating JL, Leboeuf-Yde C. Research methods for subgrouping low