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Computerized adaptive test for patients with foot or ankle impairments produced valid and responsive measures of function

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Abstract

Objective

We tested the item response theory (IRT) model assumptions of the original item bank, and evaluated the practical and psychometric adequacy, of a computerized adaptive test (CAT) for patients with foot or ankle impairments seeking rehabilitation in outpatient therapy clinics.

Methods

Data from 10,287 patients with foot or ankle impairments receiving outpatient physical therapy were analyzed. We first examined the unidimensionality, fit, and invariance IRT assumptions of the CAT item bank. Then we evaluated the efficiency of the CAT administration and construct validity and sensitivity of change of the foot/ankle CAT measure of lower-extremity functional status (FS).

Results

Results supported unidimensionality, model fit, and invariance of item parameters and patient ability estimates. On average, the CAT used seven items to produce precise estimates of FS that adequately covered the content range with negligible floor and ceiling effects. Patients who were older, had more chronic symptoms, had more surgeries, had more comorbidities, and did not exercise prior to receiving rehabilitation reported worse discharge FS. Seventy-one percent of patients obtained statistically significant change at follow-up. Change of 8 FS units (scale 0–100) represented minimal clinically important improvement.

Conclusions

We concluded that the foot/ankle item bank met IRT assumptions and that the CAT FS measure was precise, valid, and responsive, supporting its use in routine clinical application.

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Abbreviations

ANCOVA:

Analyses of covariance

AUC:

Area under the ROC curve

CAT:

Computerized adaptive testing

CI:

Confidence interval

CPT:

Current procedural terminology

CSEM:

Conditional standard error of measurement

df:

Degrees of freedom

DIF:

Differential item functioning

FCI:

Functional comorbidity index

FOTO:

Focus on Therapeutic Outcomes, Inc.

FS:

Functional status

GROC:

Global rating of change

HMO:

Health maintenance organization

ICD-9:

International classification of disease, 9th revision

IRT:

Item response theory

LEFS:

Lower-Extremity Functional Scale

Max:

Maximum

Min:

Minimum

MDC:

Minimal detectable change

MCII:

Minimal clinically important improvement

P:

Probability

PPO:

Preferred provider organization

PRO:

Patient-reported outcome

RCI:

Reliable change index

ROC:

Receiver-operating-characteristic analysis

SD:

Standard deviation

SE:

Standard error

SEM:

Standard error of measurement

t :

t-Test

References

  1. Wainer, H. (Ed.). (2000). Computerized adaptive testing. A primer (2nd ed.). Mahway, NJ: Lawrence Erlbaum.

    Google Scholar 

  2. Hambleton, R. K., Swaminathan, H., & Rogers, H. J. (1991). Fundamentals of item response theory. Newbury Park, CA: Sage.

    Google Scholar 

  3. Hays, R. D., Morales, L. S., & Reise, S. P. (2000). Item response theory and health outcomes measurement in the 21st century. Medical Care, 38(9 Suppl), II28–II42.

    PubMed  CAS  Google Scholar 

  4. Sands, W. A., Waters, B. K., & McBride, J. R. (Eds.). (1997). Computerized adaptive testing. From inquiry to operation. Washington, DC: American Psychological Association.

    Google Scholar 

  5. Lord, F. M., & Novick, M. R. (1968). Statistical theories of mental test scores. Reading, MA: Addison-Wesley.

    Google Scholar 

  6. Lord, F. (1970). Some test theory for tailored testing. In W. Holtzman (Ed.), Computer-assisted instruction, testing, and guidance (pp. 139–183). New York, NY: Harper and Row.

    Google Scholar 

  7. Ware, J. E., Bjorner, J. B., Jr., & Kosinski, M. (2000). Practical implications of item response theory and computerized adaptive testing: A brief summary of ongoing studies of widely used headache impact scales. Medical Care, 38(9 Suppl), II73–II82.

    PubMed  Google Scholar 

  8. Ware, J. E., Jr., Kosinski, M., Bjorner, J. B., Bayliss, M. S., Batenhorst, A., Dahlof, C. G., et al. (2003). Applications of computerized adaptive testing (CAT) to the assessment of headache impact. Quality of Life Research, 12(8), 935–952. doi:10.1023/A:1026115230284.

    Article  PubMed  Google Scholar 

  9. Jette, A. M., Haley, S. M., Tao, W., Ni, P., Moed, R., Meyers, D., et al. (2007). Prospective evaluation of the AM-PAC-CAT in outpatient rehabilitation settings. Physical Therapy, 87(4), 385–398.

    PubMed  Google Scholar 

  10. McHorney, C. A. (1997). Generic health measurement: Past accomplishments and a measurement paradigm for the 21st century. Annals of Internal Medicine, 127(8 Pt 2), 743–750.

    PubMed  CAS  Google Scholar 

  11. Patrick, D. L., & Chiang, Y. P. (2000). Convening health outcomes methodologists. Medical Care, 38(9, Suppl), II3–II6.

    PubMed  CAS  Google Scholar 

  12. Revicki, D. A., & Cella, D. F. (1997). Health status assessment for the twenty-first century: Item response theory, item banking and computer adaptive testing. Quality of Life Research, 6(6), 595–600. doi:10.1023/A:1018420418455.

    Article  PubMed  CAS  Google Scholar 

  13. Haley, S. M., Ni, P., Hambleton, R. K., Slavin, M. D., & Jette, A. M. (2006). Computer adaptive testing improved accuracy and precision of scores over random item selection in a physical functioning item bank. Journal of Clinical Epidemiology, 59(11), 1174–1182. doi:10.1016/j.jclinepi.2006.02.010.

    Article  PubMed  Google Scholar 

  14. Hart, D. L., Cook, K. F., Mioduski, J. E., Teal, C. R., & Crane, P. K. (2006). Simulated computerized adaptive test for patients with shoulder impairments was efficient and produced valid measures of function. Journal of Clinical Epidemiology, 59(3), 290–298. doi:10.1016/j.jclinepi.2005.08.006.

    Article  PubMed  Google Scholar 

  15. Hart, D. L., Mioduski, J. E., & Stratford, P. W. (2005). Simulated computerized adaptive tests for measuring functional status were efficient with good discriminant validity in patients with hip, knee, or foot/ankle impairments. Journal of Clinical Epidemiology, 58(6), 629–638. doi:10.1016/j.jclinepi.2004.12.004.

    Article  PubMed  Google Scholar 

  16. Hart, D. L., Mioduski, J. E., Werneke, M. W., & Stratford, P. W. (2006). Simulated computerized adaptive test for patients with lumbar spine impairments was efficient and produced valid measures of function. Journal of Clinical Epidemiology, 59(9), 947–956. doi:10.1016/j.jclinepi.2005.10.017.

    Article  PubMed  Google Scholar 

  17. Ware, J. E., Gandek, B., Sinclair, S. J., & Bjorner, J. (2005). Item response theory in computer adaptive testing: Implications for outcomes measurement in rehabilitation. Rehabilitation Psychology, 50, 71–78. doi:10.1037/0090-5550.50.1.71.

    Article  Google Scholar 

  18. Deutscher, D., Hart, D. L., Dickstein, R., Horn, S. D., & Gutvirtz, M. (2008). Implementing an integrated electronic outcomes and electronic health record process to create a foundation for clinical practice improvement. Physical Therapy, 88(2), 270–285.

    PubMed  Google Scholar 

  19. Hart, D. L., & Connolly, J. B. (2006). Pay-for-performance for physical therapy and occupational therapy: Medicare part B services. Grant #18-P-93066/9-01. Health & Human Services/Centers for Medicare & Medicaid Services.

  20. Hart, D. L., Wang, Y. C., Stratford, P. W., & Mioduski, J. E. (2008). Computerized adaptive test for patients with knee impairments produced valid and responsive measures of function. Journal of Clinical Epidemiology, July 9. doi:10.1016/j.jclinepi.2008.01.005.

  21. Hart, D. L., Wang, Y. C., Stratford, P. W., & Mioduski, J. E. (2008). Computerized adaptive test for patients with hip impairments produced valid and responsive measures of function. Archives of Physical Medicine and Rehabilitation, i.

  22. Rose, M., Bjorner, J. B., Becker, J., Fries, J. F., & Ware, J. E. (2008). Evaluation of a preliminary physical function item bank supported the expected advantages of the Patient-Reported Outcomes Measurement Information System (PROMIS). Journal of Clinical Epidemiology, 61(1), 17–33. doi:10.1016/j.jclinepi.2006.06.025.

    Article  PubMed  CAS  Google Scholar 

  23. Cella, D., Yount, S., Rothrock, N., Gershon, R., Cook, K., Reeve, B., et al. (2007). The Patient-Reported Outcomes Measurement Information System (PROMIS): progress of an NIH Roadmap cooperative group during its first two years. Medical Care, 45(5 Suppl 1), S3–S11. doi:10.1097/01.mlr.0000258615.42478.55.

    Article  PubMed  Google Scholar 

  24. Fliege, H., Becker, J., Walter, O. B., Bjorner, J. B., Klapp, B. F., & Rose, M. (2005). Development of a computer-adaptive test for depression (D-CAT). Quality of Life Research, 14(10), 2277–2291. doi:10.1007/s11136-005-6651-9.

    Article  PubMed  Google Scholar 

  25. Haley, S. M., Raczek, A. E., Coster, W. J., Dumas, H. M., & Fragala-Pinkham, M. A. (2005). Assessing mobility in children using a computer adaptive testing version of the pediatric evaluation of disability inventory. Archives of Physical Medicine and Rehabilitation, 86(5), 932–939. doi:10.1016/j.apmr.2004.10.032.

    Article  PubMed  Google Scholar 

  26. Haley, S. M., Coster, W. J., Andres, P. L., Kosinski, M., & Ni, P. (2004). Score comparability of short forms and computerized adaptive testing: Simulation study with the activity measure for post-acute care. Archives of Physical Medicine and Rehabilitation, 85(4), 661–666. doi:10.1016/j.apmr.2003.08.097.

    Article  PubMed  Google Scholar 

  27. Haley, S. M., Coster, W. J., Andres, P. L., Ludlow, L. H., Ni, P., Bond, T. L., et al. (2004). Activity outcome measurement for postacute care. Medical Care, 42(1, Suppl), I49–I61.

    PubMed  Google Scholar 

  28. American Physical Therapy Association. (2001). Guide to physical therapist practice. Physical Therapy, 81(1), 1–768.

    Google Scholar 

  29. Resnik, L., & Hart, D. L. (2003). Using clinical outcomes to identify expert physical therapists. Physical Therapy, 83(11), 990–1002.

    PubMed  Google Scholar 

  30. Centers for Medicare and Medicaid Services. (2007). Physician quality reporting initiative (PQRI). Physician quality measures. Centers for Medicare and Medicaid Services.

  31. Swinkels, I. C. S., van den Ende, C. H. M., de Bakker, D., van der Wees, J., Hart, D. L., Deutscher, D., et al. (2007). Clinical databases in physical therapy. Physiotherapy Theory and Practice, 23(3), 153–167. doi:10.1080/09593980701209097.

    Article  PubMed  CAS  Google Scholar 

  32. Alcock, G. K., & Stratford, P. W. (2002). Validation of the lower extremity functional scale on athletic subjects with ankle sprains. Physiotherapy Canada, 54, 233–240.

    Google Scholar 

  33. Binkley, J. M., Stratford, P. W., Lott, S. A., & Riddle, D. L. (1999). The lower extremity functional scale (LEFS): Scale development, measurement properties, and clinical application North American Orthopaedic Rehabilitation Research Network. Physical Therapy, 79(4), 371–383.

    PubMed  CAS  Google Scholar 

  34. Stratford, P. W., Hart, D. L., Binkley, J. M., Kennedy, D. M., Alcock, G. K., & Hanna, S. E. (2005). Interpreting lower extremity functional status scores. Physiotherapy Canada, 57, 154–162. doi:10.2310/6640.2005.00023.

    Article  Google Scholar 

  35. World Health Organization. (2001). International classification of functioning, disability and health. Geneva: World Health Organization.

    Google Scholar 

  36. Andrich, D. (1978). A rating formulation for ordered response categories. Psychometrika, 43(4), 561–573. doi:10.1007/BF02293814.

    Article  Google Scholar 

  37. Millsap, R. E., & Everson, H. T. (1993). Methodology review: Statistical approaches for assessing measurement bias. Applied Psychological Measurement, 17, 287–334.

    Google Scholar 

  38. Crane, P. K., Hart, D. L., Gibbons, L. E., & Cook, K. F. (2006). A 37-item shoulder functional status item pool had negligible differential item functioning. Journal of Clinical Epidemiology, 59(5), 478–484. doi:10.1016/j.jclinepi.2005.10.007.

    Article  PubMed  Google Scholar 

  39. Thissen, D., & Mislevy, R. J. (2000). Testing algorithms. In H. Wainer (Ed.), Computerized adaptive testing: A primer (2nd ed., pp. 101–134). Mahwah, NJ: Lawrence Erlbaum.

    Google Scholar 

  40. Hart, D. L., & Mioduski, J. E. (2006). CAT development and testing software user’s guide. Knoxville, TN: FOTO, Inc.

    Google Scholar 

  41. Lord, F. M. (1980). Applications of item response theory to practical testing problems. Hillsdale, NJ: Lawrence Erlbaum.

    Google Scholar 

  42. Linacre, J. M. (1998). Estimating measures with known polytomous item difficulties. Rasch Measurement Transactions, 12(2), 638.

    Google Scholar 

  43. Linacre, J. M. A. (2008). User’s guide to WINSTEPS. Chicago, IL: MESA.

    Google Scholar 

  44. Bond, T. G., & Fox, C. M. (2001). Applying the Rasch model. Mahwah, NJ: Lawrence Erlbaum.

    Google Scholar 

  45. Camilli, G., & Shepard, L. A. (1994). Methods for identifying biased test items. Thousand Oaks, CA: Sage.

    Google Scholar 

  46. Steinberg, L., Thissen, D., & Wainer, H. (2000). Validity. In H. Wainer (Ed.), Computerized adaptive testing: A primer (pp. 185–229). Mahwah, NJ: Lawerence Erlbaum.

    Google Scholar 

  47. Crane, P. K., Gibbons, L. E., Ocepek-Welikson, K., Cook, K., Cella, D., Narasimhalu, K., et al. (2007). A comparison of three sets of criteria for determining the presence of differential item functioning using ordinal logistic regression. Quality of Life Research, 16(Suppl 1), 69–84. doi:10.1007/s11136-007-9185-5.

    Article  PubMed  Google Scholar 

  48. Crane, P. K., van Belle, G., & Larson, E. B. (2004). Test bias in a cognitive test: Differential item functioning in the CASI. Statistics in Medicine, 23(2), 241–256. doi:10.1002/sim.1713.

    Article  PubMed  Google Scholar 

  49. Samejima, F. (1969). Estimation of ability using a response pattern of graded responses. Psycometrika, Monograph 17.

  50. PARSCALE for Windows.v 4.1. (2003). Lincolnwood, IL: Scientific Software International.

  51. Stata Statistical Software. (2007). Release 9.2. College Station, TX.

  52. Crane, P. K., Gibbons, L. E., Jolley, L., & van Belle, G. (2006). Differential item functioning analysis with ordinal logistic regression techniques. DIFdetect and difwithpar. Medical Care, 44(11, Suppl 3), S115–S123. doi:10.1097/01.mlr.0000245183.28384.ed.

    Article  PubMed  Google Scholar 

  53. Groll, D. L., To, T., Bombardier, C., & Wright, J. G. (2005). The development of a comorbidity index with physical function as the outcome. Journal of Clinical Epidemiology, 58(6), 595–602. doi:10.1016/j.jclinepi.2004.10.018.

    Article  PubMed  Google Scholar 

  54. Vickers, A. J., & Altman, D. G. (2001). Statistics notes: Analysing controlled trials with baseline and follow up measurements. BMJ (Clinical Research Ed.), 323(7321), 1123–1124. doi:10.1136/bmj.323.7321.1123.

    Article  CAS  Google Scholar 

  55. Bland, J. M., & Altman, D. G. (1994). Regression towards the mean. BMJ (Clinical Research Ed.), 308(6942), 1499.

    CAS  Google Scholar 

  56. Resnik, L., Feng, Z., & Hart, D. L. (2006). State regulation and the delivery of physical therapy services. Health Services Research, 41(4 Pt 1), 1296–1316.

    PubMed  Google Scholar 

  57. Wyrwich, K. W., Tierney, W. M., & Wolinsky, F. D. (1999). Further evidence supporting an SEM-based criterion for identifying meaningful intra-individual changes in health-related quality of life. Journal of Clinical Epidemiology, 52(9), 861–873. doi:10.1016/S0895-4356(99)00071-2.

    Article  PubMed  CAS  Google Scholar 

  58. Hsieh, Y. W., Wang, C. H., Wu, S. C., Chen, P. C., Sheu, C. F., & Hsieh, C. L. (2007). Establishing the minimal clinically important difference of the Barthel Index in stroke patients. Neurorehabilitation and Neural Repair, 21(3), 233–238. doi:10.1177/1545968306294729.

    Article  PubMed  Google Scholar 

  59. Schmitt, J. S., & Di Fabio, R. P. (2004). Reliable change and minimum important difference (MID) proportions facilitated group responsiveness comparisons using individual threshold criteria. Journal of Clinical Epidemiology, 57(10), 1008–1018. doi:10.1016/j.jclinepi.2004.02.007.

    Article  PubMed  Google Scholar 

  60. Hays, R. D., Brodsky, M., Johnston, M. F., Spritzer, K. L., & Hui, K. K. (2005). Evaluating the statistical significance of health-related quality-of-life change in individual patients. Evaluation and the Health Professions, 28(2), 160–171. doi:10.1177/0163278705275339.

    Article  Google Scholar 

  61. Beaton, D. E., Bombardier, C., Katz, J. N., & Wright, J. G. (2001). A taxonomy for responsiveness. Journal of Clinical Epidemiology, 54(12), 1204–1217. doi:10.1016/S0895-4356(01)00407-3.

    Article  PubMed  CAS  Google Scholar 

  62. Jaeschke, R., Singer, J., & Guyatt, G. H. (1989). Measurement of health status. Ascertaining the minimal clinically important difference. Controlled Clinical Trials, 10(4), 407–415. doi:10.1016/0197-2456(89)90005-6.

    Article  PubMed  CAS  Google Scholar 

  63. Stratford, P. W., Binkley, J. M., Watson, J., & Heath-Jones, T. (2000). Validation of the LEFS on patients with total joint arthroplasty. Physiotherapy Canada, 52, 97–205.

    Google Scholar 

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Acknowledgments

The authors would like to thank Karon F. Cook, PhD for her insightful comments regarding statistical analyses, results, and manuscript edits.

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Authors and Affiliations

  1. Focus on Therapeutic Outcomes, Inc., 551 Yopps Cove Road, White Stone, VA, 22578-2403, USA

    Dennis L. Hart, Ying-Chih Wang & Jerome E. Mioduski

  2. Sensory Motor Performance Program (SMPP), Rehabilitation Institute of Chicago, Chicago, IL, USA

    Ying-Chih Wang

  3. Department of Clinical Epidemiology and Biostatistics, School of Rehabilitation Science, McMaster University, Hamilton, ON, Canada

    Paul W. Stratford

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  1. Dennis L. Hart
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Correspondence to Dennis L. Hart.

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Hart, D.L., Wang, YC., Stratford, P.W. et al. Computerized adaptive test for patients with foot or ankle impairments produced valid and responsive measures of function. Qual Life Res 17, 1081–1091 (2008). https://doi.org/10.1007/s11136-008-9381-y

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