The Conceptual Framework for the Work Disability Functional Assessment Battery (WD- FAB) Diane Brandt, PT, MS, PhD Collaboration to Improve the US Disability Determination Process

Disclosure I have no potential conflict of interest to report

Escalating demands US Social Security Administration (SSA) Disability Programs pressured by rise in applications - Aging population -Increasing claims among veterans -Economic climate Reform efforts constrained by the sheer number of applicants and beneficiaries –How do you assess functional status for millions of new applicants and current beneficiaries?

SSA’s statutory definition of disability (circa 1956) Identify individuals unable to engage in substantial gainful employment (SGE) due to medically determinable physical or mental impairment/s expected to result in death or last > 12 months … SEC [42 U.S.C. 423](d)(1) Impairment/s of such severity that individual unable to do previous work and (given age/education/work experience) cannot engage in other SGE in national economy … SEC [42 U.S.C. 423](d)(2)(A)

Application Intake Process SSA field offices verify non-medical eligibility requirements, which may include age, employment, marital status, or Social Security coverage information DDS are funded by the Federal Government and responsible for developing medical evidence and making the initial determination on whether or not a claimant is disabled or blind under the law There are 101 DDS offices across the 50 states and territories Application Via phone, mail, Web, in-person Processed initially by SSA field offices (1,250 office across the US) State disability determination service (DDS) office for evaluation of disability

Collaboration August, 2007 In this context, SSA sought help from NIH institutes and centers Identify new diagnostic tests to expedite allowances Paradigm: Diagnosis or impairment ≈ disability SSA/RMD Inter-Agency Agreement 8-year agreement beginning in February 2008 Brings research funds into NIH-RMD

Whole Person Approach Capture all conditions during the application process …. to characterize the sum total of their impact on functioning as it relates to work Depression Knee arthritis Heart disease

Health Condition Activities Participation Environmental Factors Personal Factors Body Functions Body Structures ICF: World Health Organization, 2001 Conceptual Gap Work

Building the Work Disability Functional Assessment Batteries (WD-FAB) using Item Response Theory (IRT) and computer adaptive testing (CAT)

(IRT) Item Response Theory Methodology… Questions are chosen to cover the range of function in one dimension (eg, mobility) Questions in each domain are ordered hierarchically along a scale Each question provides different information about the domain of functioning Scores are calibrated to an equal interval score More Difficult Are you able to run fast for 2 minutes Are you able to remain on your feet for 6 hours with short breaks? Are you able to walk up a steep slope? For example on a hill. Are you able walk up a flight of stairs without a handrail? Are you able to kneel down to tie a shoe? Are you able to get into and out of a car? Less Difficult

What is CAT? Questions selected from a large IRT calibrated ‘item bank’ A computerized algorithm selects items based on how a person responds to previous items

Why Build CATs? Efficient –Redundant or irrelevant items are not used – Current instrument is composed of 313 items yet completed in ~15 minutes Multiple modes of administration –Web; phone; in-person; short forms Maintains assessment accuracy & precision Claimant functional profiles can be created Item pools can be replenished & improved Feasible for use with periodic re- determinations

Development Timeline Develop item pools (~1 year) –Extensive literature review –Focus groups –Content experts –Cognitive Testing Ask about question comprehension, decision processes and response processes Calibration study (~1 year) –Administer items to user groups Analyze outcomes to finalize item banks Develop CAT software

Cognition & Communication Cognition & Communication Covering the waterfront ICF Activity Domains MobilityCommunication Learning and Applying Knowledge Self Care General Tasks and Demands Basic Mobility Upper Body Function Community Mobility Resilience/ Sociability Mood & Emotions Self- Regulation Interpersonal Interactions and Relationships WD FAB Content Domains Fine Motor Function

Thank you! Questions? Diane Brandt PT, MS, PhD