Outcome Instruments


The Boston University Activity Measure for Post Acute Care (AM-PACTM) originally published in 2004, is an activity limitations instrument developed by researchers at Boston University's Health and Disability Research Institute. The World Health Organization’s International Classification of Functioning, Disability and Health (ICF) is the conceptual framework for the AM-PAC. According to the ICF, an activity limitation is defined as “difficulty in the execution of a task or action by an individual.”





The Pediatric Evaluation of Disability Inventory (PEDITM), originally published in 1992, has been revised as a computer adaptive test (CAT) - the PEDI-CAT. It is designed for use with children and youth from birth until 21 years of age with a variety of physical and/or behavioral conditions. The PEDI-CAT measures abilities in the three functional domains of Daily Activities, Mobility and Social/Cognitive. The PEDI-CAT’s Responsibility domain measures the extent to which the caregiver or child takes responsibility for managing complex, multi-step life tasks. The PEDI-CAT can be used across all clinical diagnoses and community settings. As with the original paper-pencil PEDI, the PEDI-CAT can be administered by professional judgment of clinicians or educators who are familiar with the child or by parent report.





The Pediatric Evaluation of Disability Inventory (PEDITM) is a comprehensive clinical assessment of key functions capabilities and performance in children between the ages of six months and seven years. It is a paper-based instrument. The PEDITM can be used to evaluate older children with functional abilities that are less than those expected of a 7-year-old child without disabilites. The PEDITM is a descriptive measure of a child’s current funcitonal performance and can track changes over time. The PEDITM measures both capability and performance of functional activities in three functional domains.

  • Self-care
  • Mobility
  • Social function



Late-Life Function and Disability CAT (LLFDI-CAT)

Late-Life Function & Disability Instrument - Computer Adaptive Test (LLFDI-CAT) is a patient-reported measure of ‘activity limitation’ and ‘participation restriction’ designed for community-dwelling older adults. The LLFDI-CAT is an improved and expanded version of the original Late-Life Function & Disability Instrument (LLFDI), which is a traditional, fixed-form measure developed in 2002. The conceptual framework of the World Health Organization’s (WHO) International Classification of Functioning, Disability, and Health (ICF) has been applied to operationally define distinct domains of activity limitations and participation restrictions, and develop content for the LLFDI-CAT. The ICF describes activity limitation as “limitation in the execution of a task or action by an individual”, and participation restriction as “restriction in involvement in life situations.” The LLFDI-CAT has been designed to serve as a comprehensive, precise, and efficient measure of activity limitations and participation restrictions, which can be responsive to meaningful change in each of its two domains.


Using traditional measurement methods, designing a single, comprehensive, and precise measure of Activity Limitation and Participation Restriction that has minimal floor and ceiling effects across a range of patients and settings is impractical due to the large number of items required to cover the full spectrum of functional ability. Thus, the LLFDI-CAT employs Item Response Theory (IRT) and Computer-Adaptive Testing (CAT) methods, two highly promising, contemporary measurement approaches that overcome the limitations of traditional, fixed-form measures. CAT instruments offer the dual advantage of significantly reduced administration time while maintaining good measurement breadth and precision.


A CAT instrument requires a comprehensive item bank that includes a range of items representing the construct of interest from low to high levels of ability. Using a computer algorithm, a CAT is programmed to first present an item of mid-difficulty from the item pool, and subsequently tailor administration to the respondent by selecting items of appropriate difficulty based on prior responses. Rather than initiating the test with a mid-difficulty item, CATs can also be programmed to present an initial item based on respondent information such as age, diagnosis, or condition severity. A CAT instrument is programmed to stop once a specified score precision and/or predetermined number of items administered is reached. As each subsequent item is selected based on the respondent’s estimated ability and item difficulty level, a CAT administers the optimal subset of items to each subject, avoiding inappropriately easy or difficult items. By posing the most informative questions, CATs can provide precise score estimates with fewer items compared with traditional, fixed-form tests. A unique advantage of CATs is that test length can be easily adapted to the meet needs of the specific application; a shorter test can be selected to reduce respondent burden when high precision is not required, and more items can be administered when high precision is required.


Click the link below to download the Windows PC version of the software.