Important wheelchair skills for new manual wheelchair users: health care professional and wheelchair user perspectives.

PURPOSE: The purpose of this project was to identify wheelchair skills currently being taught to new manual wheelchair users, identify areas of importance for manual wheelchair skills' training during initial rehabilitation, identify similarities and differences between the perspectives of health care professionals and manual wheelchair users and use the ICF to organize themes related to rehabilitation and learning how to use a manual wheelchair. METHOD: Focus groups were conducted with health care professionals and experienced manual wheelchair users. ICF codes were used to identify focus group themes. RESULTS: The Activities and Participation codes were more frequently used than Structure, Function and Environment codes. Wheelchair skills identified as important for new manual wheelchair users included propulsion techniques, transfers in an out of the wheelchair, providing maintenance to the wheelchair and navigating barriers such as curbs, ramps and rough terrain. Health care professionals and manual wheelchair users identified the need to incorporate the environment (home and community) into the wheelchair training program. CONCLUSIONS: Identifying essential components for training the proper propulsion mechanics and wheelchair skills in new manual wheelchair users is an important step in preventing future health and participation restrictions. Implications for Rehabilitation Wheelchair skills are being addressed frequently during rehabilitation at the activity-dependent level. Propulsion techniques, transfers in an out of the wheelchair, providing maintenance to the wheelchair and navigating barriers such as curbs, ramps and rough terrain are important skills to address during wheelchair training. Environment factors (in the home and community) are important to incorporate into wheelchair training to maximize safe and multiple-environmental-setting uses of manual wheelchairs. The ICF has application to understanding manual wheelchair rehabilitation for wheelchair users and therapists for improving the understanding of manual wheelchair use.

Measuring Environmental Factors: Unique and Overlapping International Classification of Functioning, Disability and Health Coverage of 5 Instruments.

OBJECTIVES: To describe the unique and overlapping content of the newly developed Environmental Factors Item Banks (EFIB) and 7 legacy environmental factor instruments, and to evaluate the EFIB's construct validity by examining associations with legacy instruments. DESIGN: Cross-sectional, observational cohort. SETTING: Community. PARTICIPANTS: A sample of community-dwelling adults with stroke, spinal cord injury, and traumatic brain injury (N=568). INTERVENTIONS: None. MAIN OUTCOME MEASURES: EFIB covering domains of the built and natural environment; systems, services, and policies; social environment; and access to information and technology; the Craig Hospital Inventory of Environmental Factors (CHIEF) short form; the Facilitators and Barriers Survey/Mobility (FABS/M) short form; the Home and Community Environment Instrument (HACE); the Measure of the Quality of the Environment (MQE) short form; and 3 of the Patient Reported Outcomes Measurement Information System's (PROMIS) Quality of Social Support measures. RESULTS: The EFIB and legacy instruments assess most of the International Classification of Functioning, Disability and Health (ICF) environmental factors chapters, including chapter 1 (products and technology; 75 items corresponding to 11 codes), chapter 2 (natural environment and human-made changes; 31 items corresponding to 7 codes), chapter 3 (support and relationships; 74 items corresponding to 7 codes), chapter 4 (attitudes; 83 items corresponding to 8 codes), and chapter 5 (services, systems, and policies; 72 items corresponding to 16 codes). Construct validity is provided by moderate correlations between EFIB measures and the CHIEF, MQE barriers, HACE technology mobility, FABS/M community built features, and PROMIS item banks and by small correlations with other legacy instruments. Only 5 of the 66 legacy instrument correlation coefficients are moderate, suggesting they measure unique aspects of the environment, whereas all intra-EFIB correlations were at least moderate. CONCLUSIONS: The EFIB measures provide a brief and focused assessment of ICF environmental factor chapters. The pattern of correlations with legacy instruments provides initial evidence of construct validity.

Using the ICF's environmental factors framework to develop an item bank measuring built and natural environmental features affecting persons with disabilities.

OBJECTIVES: To develop a measure of natural environment and human-made change features (Chapter 2 of the international classification of functioning, disability, and health) and evaluate the influence of perceived barriers on health-related quality of life. METHODS: A sample of 570 adults with stroke, spinal cord injury, and traumatic brain injury residing in community settings reported their functioning in home, outdoor, and community settings (mean age = 47.0 years, SD = 16.1). They rated 18 items with a 5-point rating scale to describe the influence of barriers to moving around, seeing objects, hearing sounds, hearing conversations, feeling safe, and regulating temperature and indicated whether any difficulties were due to environmental features. We used Rasch analysis to identify misfitting items and evaluate differential item functioning (DIF) across impairment groups. We computed correlations between barriers and patient-reported outcomes measurement information system (PROMIS) social domain measures and community participation indicators (CPI) measures. RESULTS: The 18 items demonstrated person reliability of .70, discriminating nearly three levels of barriers. All items fit the Rasch model; impairment-related DIF was negligible. Ceiling effects were negligible, but 25 % of the respondents were at the floor, indicating that they did not experience barriers that they attributed to the built and natural environment. As anticipated, barriers correlated moderately with PROMIS and CPI variables, suggesting that although this new item bank measures a construct that is related to participation and health-related quality of life, it also captures something unique. Known-groups validity was supported by wheelchair users reporting a higher level of barriers than did ambulatory respondents. CONCLUSIONS: Preliminary evidence supports the reliability and validity of this new measure of barriers to the built and natural environment. This measure allows investigators and clinicians to measure perceptions of the natural environment and human-made changes, providing information that can guide interventions to reduce barriers. Moderate relationships between barriers and PROMIS and CPI variables provide support for the measurement and theory of environmental influences on social health and participation.

Theoretical foundations for the measurement of environmental factors and their impact on participation among people with disabilities.

The ascendance of the World Health Organization's International Classification of Functioning, Disability and Heath (ICF) as the global standard for describing and characterizing aspects of disability has refocused attention on the role that environmental factors (EFs) have on the health and participation of people with disabilities, both as individuals and as a group. There has been a rise in the development of instruments designed to measure EFs alone and in relation to participation. Some instrument developers have used the ICF as a theoretical base for instrument development and to substantiate content validity claims. We contend that this is a misapplication of the ICF. There is a need to step back and reexamine the role that environmental theories can play in developing a conceptually driven approach to measuring the interaction between EFs and participation. For this review, we draw on the fields of social, community, and developmental psychology; disability studies; gerontology; public health; and rehabilitation. We discuss different approaches to the measurement of EFs. We suggest that given the complex nature of EFs and their influence on participation, there is a need for a fresh approach to EF measurement. The thoughtful application of theories and the use of advanced psychometric, measurement, and e-technologies and data visualization methods may enable researchers and clinicians to better quantify, document, and communicate the dynamic interrelationship between EFs and participation and health outcomes for people with disabilities at the individual, group, and population levels.

Environmental barriers and supports to everyday participation: a qualitative insider perspective from people with disabilities.

OBJECTIVE: To describe environmental factors that influence participation of people with disabilities. DESIGN: Constant comparative, qualitative analyses of transcripts from 36 focus groups across 5 research projects. SETTING: Home, community, work, and social participation settings. PARTICIPANTS: Community-dwelling people (N=201) with diverse disabilities (primarily spinal cord injury, traumatic brain injury, and stroke) from 8 states. INTERVENTIONS: None. MAIN OUTCOME MEASURES: Environmental barriers and supports to participation. RESULTS: We developed a conceptual framework to describe how environmental factors influence the participation of people with disabilities, highlighting 8 domains of environmental facilitators and barriers (built, natural, assistive technology, transportation, information and technology access, social support and attitudes, systems and policies, economics) and a transactional model showing the influence of environmental factors on participation at the micro (individual), mesa (community), and macro (societal) levels. Focus group data validated some International Classification of Functioning, Disability and Health environmental categories while also bringing unique factors (eg, information and technology access, economic quality of life) to the fore. Data were used to construct items to enable people with disabilities to assess the impact of environmental factors on everyday participation from their firsthand experience. CONCLUSIONS: Participants with disabilities voiced the need to evaluate the impact of the environment on their participation at the immediate, community, and societal levels. The results have implications for assessing environmental facilitators and barriers to participation within rehabilitation and community settings, evaluating outcomes of environmental interventions, and effecting system and policy changes to target environmental barriers that may result in societal participation disparities versus opportunities.

Environmental factors item development for persons with stroke, traumatic brain injury, and spinal cord injury.

OBJECTIVES: To describe methods used in operationalizing environmental factors; to describe the results of a research project to develop measures of environmental factors that affect participation; and to define an initial item set of facilitators and barriers to participation after stroke, traumatic brain injury, and spinal cord injury. DESIGN: Instrument development included an extensive literature review, item classification and selection, item writing, and cognitive testing following the approach of the Patient-Reported Outcomes Measurement Information System. SETTING: Community. PARTICIPANTS: Content area and outcome measurement experts (n=10) contributed to instrument development; individuals (n=200) with the target conditions participated in focus groups and in cognitive testing (n=15). INTERVENTIONS: None. MAIN OUTCOME MEASURES: Environmental factor items were categorized in 6 domains: assistive technology; built and natural environment; social environment; services, systems, and policies; access to information and technology; and economic quality of life. RESULTS: We binned 2273 items across the 6 domains, winnowed this pool to 291 items for cognitive testing, and recommended 274 items for pilot data collection. CONCLUSIONS: Five of the 6 domains correspond closely to the International Classification of Functioning, Disability and Health taxonomy of environmental factors; the sixth domain, economic quality of life, reflects an important construct that reflects financial resources that affect participation. Testing with a new and larger sample is underway to evaluate reliability, validity, and sensitivity.

Person factors and work environments of workers who use mobility devices.

BACKGROUND: Nearly 25% of people with mobility impairments and limitations who are of working age are employed, yet few studies have examined their perspectives on their jobs or work environments required to complete job tasks. OBJECTIVE: The purpose of this study was to describe the factors that contribute to successful employment for those who use mobility devices. PARTICIPANTS: A convenience sample of 132 workers who use power wheelchairs, manual wheelchairs, canes, crutches or walkers. METHOD: Participants completed an online version of the Mobility Device User Work Survey (MWS). A multivariate analysis and a two-step multiple linear regression analysis were used. RESULTS: Study participants had few secondary health conditions that influenced their work. Employee satisfactoriness to their employers was high. Accessibility of worksites was high. Assistive technologies were inexpensive, and personal assistance was used infrequently and usually was unpaid. Co-worker communications were very positive. Flexible work rules and supportive managers were highly valued. Job satisfaction positively correlated with accessibility, work tasks, co-worker communication and work support. CONCLUSION: The description of work environments of successfully employed mobility device users can provide some useful guidance to employers, vocational rehabilitation (VR) counselors and unemployed mobility device users to balance employee abilities and preferences with the needs of employers.

The development of an instrumented wheelchair propulsion testing and training device.

Researchers have used several types of testing devices and training surfaces to examine wheelchair propulsion. Testing and training wheelchair users on the actual surface of interest, such as tile floors or ramps, is ideal but difficult. Devices such as treadmills, dynamometers, and ergometers allow for researchers and clinicians to observe wheelchair users in a controlled space. However, these devices often do not have the ability to realistically simulate the environment. This methodological article describes the instrumentation, development and function of a wheelchair dynamometer system, the WheelMill System (WMS), a uniquely adjustable roller system for wheelchairs. Three participants wheeled on the WMS, over a tile surface and up two different graded slopes with the SmartWheel to compare speed and forces. The WMS reasonably simulated propulsion over a tile floor, though the participants' speed was slightly faster on tile, and the peak forces for each propulsion stroke varied more on tile than on the WMS. For the slopes, the speed oscillated over a greater range and was slower, and the measured peak forces were higher than the values measured on the WMS. The WMS may have several applications, though additional studies on a greater and more diverse population are needed.

Interviews with employed people with mobility impairments and limitations: environmental supports impacting work acquisition and satisfaction.

BACKGROUND: Less than 40% of people with disabilities work. Many studies have detailed the barriers to employment but few have examined the work experiences of those who are employed. OBJECTIVE: A description of work conditions valued by a specific segment of employed people with disabilities is provided. METHODS: Videotaped interviews of 33 successfully employed people with mobility impairments and limitations (PWMIL) were transcribed and analyzed to gather their perspectives on their work social and physical environments. RESULTS: Finding work was facilitated by family, friends and other social networks, vocational services, and prior education. Doing volunteer work, spending time at a paid and unpaid internship, and part-time work experiences were important aspects of job acquisition. Exterior and interior physical features were or had been made accessible. Expensive assistive technologies were paid for by the employee and their health insurance. Almost all personal assistance was provided by family, friends and co-workers. Work satisfaction included having a supportive employer, supportive co-workers, and flexible worksite policies. CONCLUSION: The interviews of employed PWMIL provide prospective employers and employees information on important social and physical work features that are needed to improve the possibilities for hiring people with disabilities and facilitating their successful careers.

Work environments of people with mobility impairments and limitations: Mobility Device User Work Survey (MWS).

BACKGROUND: Few studies of employed people who use wheelchairs, canes, crutches or walkers have been reported in the literature. One reason for this paucity of research reports is that surveys are most often made of unemployed individuals with disabilities a defined broadly. Understanding the work site of successfully employed people who use mobility devices requires the development of as survey that can be used to examine the important features of worksite from employees who use mobility devices at their worksites. OBJECTIVE: This article describes the development and psychometrics of a survey on currently employed people with lower limb impairments and mobility limitations who use mobility devices. The items in the Mobility Device User Work Survey (MWS) were based on interviews and survey items pilot tested on employed mobility device users. PARTICIPANTS: A sample of 183 employed people who use mobility devices including wheelchairs, canes, crutches or walkers was recruited using internet postings on disability-related organizations. The average age of the sample was 46.3, most were college educated, 72% used wheelchairs and the average number of years of employment was 24. METHODS: The MWS was completed by 183 people who met the inclusion criteria. The survey was sent to these same people a second time and 132 of them returned the second survey. RESULTS: The MWS consists of 106 questions on demographic, work and worksite characteristics and 58 subjective evaluation items that were organized into five scales. The internal consistencies (Cronbach's alpha) of the five scales were moderate (0.72) to good (0.93). Stability values of the five scales were calculated using correlations between forms and ranged from 0.70 to 0.80. The evaluative scales were analyzed using exploratory factor analysis. CONCLUSIONS: The MWS provides a tool for studying the variables that influence employed people who use mobility devices. Future studies of unemployed people who use mobility devices may benefit from using the results of the MWS to plan interventions.

Measuring impact of environmental factors on human functioning and disability: a review of various scientific approaches.

PURPOSE: The objective of this paper is to present a framework for systematically describing different approaches to measure environmental factors (EF) and to discuss some strengths and weaknesses of these approaches. METHODS: Identification of suitable criteria for ordering measurements of EF was based on an analysis of existing reviews, a qualitative literature review and feedback from experts. Items of selected EF measures were linked to the International Classification of Functioning, Disability and Health. RESULTS: Experimental and observational designs for the study of EF are distinguished and illustrated with examples. Approaches to study EF are differentiated into those directly measuring an environmental interaction with function and those relying on an independent assessment of environmental features. By applying these criteria, a three-dimensional matrix framework for measurement of EF in observational studies is developed. CONCLUSION: The acknowledgement of different measurement approaches to the scientific study of EF is one pathway towards an increased understanding of the connection between environments and functioning. Many different measures may be used to approximate the realities of disabling or enabling environments. This review provides an initial framework for improving our fundamental comprehension of the complexity of the measurement of EF in the context of human health and disability.

Development of an item bank for a computerised adaptive test of upper-extremity function.

PURPOSE: The purpose of this study was to determine the psychometric characteristics of an upper-extremity item bank as a precursor to developing a computer adaptive patient reported outcome instrument. The Activity dimension of the World Health Organization's International Classification of Functioning, Disability and Health (ICF) provided the conceptual framework for the items. METHOD: Factor and Rasch analyses were used to evaluate the psychometric properties of the item bank, including: monotonicity, local independence, dimensionality, item difficulty hierarchy and match between sample ability and item difficulty. RESULTS: Monotonicity of the rating scale was supported. Nine item pairs were locally dependent, and thus one item from each pair was removed from subsequent analyses. There was evidence for two unidimensional constructs; gross upper-extremity and fine hand. Both constructs showed good internal consistency and person separation. In general, the order of item difficulty within each construct replicated the hypothesised item difficulty order. The fine hand construct had a ceiling effect. CONCLUSIONS: The above study of our newly developed upper-extremity item bank empirically verified the intended item difficulty order, identified separate constructs (i.e. gross upper-extremity and fine hand) and provided insights into eliminating the ceiling effect of one of the constructs. These findings are critical precursors to the development of upper-extremity components of the ICF Activity Measure, an ICF-based, CAT located on the web at: www.icfmeasure.phhp.ufl.edu.

Development of a community mobility skills course for people who use mobility devices.

OBJECTIVE: We assessed mobility device skills in a lived-in environment on a community mobility skills course (CMSC) and related those skills to previously demonstrated skills in a controlled environment on an inside mobility skills course (IMSC). METHOD: Six mobility device users were selected from 91 adults who had previously completed the IMSC. Each of the following device groups was represented: power wheelchair, manual wheelchair, scooter, cane, crutch, and walker. CMSC tasks were modified from IMSC tasks and designed using materials in the community. RESULTS: All participants completed at least half of the CMSC tasks faster than they completed the corresponding IMSC tasks. The number of tasks on which participants improved and the amount of improvement varied by difficulty of task and mobility device used. CONCLUSION: Some mobility device skills used in controlled environments appear to transfer to community settings; others do not. Skills required for community participation may partially depend on mobility device used.

Structural equation modeling of the relationships between participation in leisure activities and community environments by people with mobility impairments.

OBJECTIVE: To examine the linkages between the constructs of participation and the environment for a set of leisure activities (attending concerts, attending movies, attending sporting events). DESIGN: Self-report surveys of the influence of the environment on participation were analyzed using structural equation modeling. Temporal, evaluative, and health-related aspects of leisure activities were selected as latent variables associated with participation. The environmental construct consisted of the latent variables of the influence on participation of the natural, interpersonal, built, background, and supportive environments. SETTING: Midwestern United States. PARTICIPANTS: A purposive sample of people (N=604) with mobility limitations. INTERVENTION: None. MAIN OUTCOME MEASURES: Measures of relationships between participation in leisure activities and the environment of people with mobility limitations. RESULTS: Structural equation modeling can be an important tool for empirically examining the contributions of the component latent variables of participation and the environment. CONCLUSIONS: A model that fits participation by people with disabling conditions in their environment can provide guidance for community-based interventions and person-based therapies.

The influence of verbal training and visual feedback on manual wheelchair propulsion.

PURPOSE: To determine if verbal training with visual feedback improved manual wheelchair propulsion; to examine propulsion differences between an individual with paraplegia and an individual with tetraplegia. METHOD: Quasi-experimental study: Nine manual wheelchair-using adults participated in propulsion assessments and training. Baseline propulsion performance was measured on several tasks on different surfaces. Participants were trained on a wheelchair treadmill with verbal and visual feedback to increase push length, reduce push frequency and to modify propulsion pattern. Handrim biomechanics were measured with an instrumented wheel. Changes in propulsion were assessed. Differences in propulsion characteristics between a participant with paraplegia and a participant with tetraplegia were examined. RESULTS: Push length increased (p < 0.05), push frequency decreased (p < 0.01) and peak (p < 0.05) and average (p < 0.01) forces increased immediately after training. These changes were not sustained over time. Graphic representations showed differences in propulsion characteristics between a participant with paraplegia and a participant with tetraplegia. CONCLUSIONS: Verbal training may produce changes in push biomechanics of manual wheelchair users. Longer training periods may be needed to sustain propulsion changes. Findings from this study support other studies that have shown propulsion differences between people with tetraplegia and paraplegia. Propulsion training for populations with upper-extremity impairments warrants further study.

Influence of a Consumer-Directed Personal Assistance Services Program on the lives of persons with mobility impairments.

OBJECTIVE: To examine the effects of a consumer-directed personal assistance services (CDPAS) program on the lives of persons with disabilities. METHODS: Thirteen individuals receiving paid agency-directed PAS services before enrollment in a CDPAS program (Agency Group) and 40 individuals receiving only unpaid PAS before enrollment (Informal Group) participated in this prospective study. In-home interviews were conducted just prior to CDPAS enrollment and again 6 months after CDPAS enrollment. RESULTS: Overall choice and satisfaction with PAS improved significantly for both groups after CDPAS initiation (p < .05). Total PAS hours increased significantly for the Informal Group (p < .01) but not the Agency Group. The Informal Group used relatives to provide the majority of its CDPAS hours, while the Agency Group chose to use nonrelatives and nonfriends to provide the majority of its CDPAS hours. Few significant changes in health status were observed for either group after the CDPAS intervention, although most changes were in the positive direction. The CDPAS program did not appear to have a large effect on individuals' personal and community participation, but participants reported a relatively high quality of participation at both time points. CONCLUSION: This study supports other findings that consumers prefer CDPAS to agency-directed care and provides new evidence that this preference cannot be explained by an increase in PAS hours that often accompanies enrollment in a CPDAS program. Although CDPAS appear to have subtle positive effects on consumer health and participation, ways in which CDPAS can maximize health status and participation quality among consumers should be explored.

The interrater reliability of the Community Health Environment Checklist.

OBJECTIVE: The purpose of this preliminary study was to examine the interrater reliability of the Community Health Environment Checklist. DESIGN: Thirty buildings were randomly selected. Three trained raters assessed each destination with the Community Health Environment Checklist. SETTING: All buildings assessed during this study were located in an urban community in St. Louis, Missouri. PARTICIPANTS: Buildings represent 13 categories of building type from a defined geographic region. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURE: The outcome measure in this study was the Community Health Environment Checklist, which is used to quantify the receptivity of public buildings from the perspectives of people with mobility impairments. RESULTS: The findings suggest that the subscales of the Community Health Environment Checklist have excellent interrater reliability coefficients, (intraclass correlation coefficient, .76-.99). CONCLUSIONS: The findings of this study provide preliminary data to support the clinical utility of the Community Health Environment Checklist as a measure of the receptivity of the physical environment for persons with mobility impairments.

People with mobility impairments: Physical activity and quality of participation.

BACKGROUND: we sought to describe the characteristics of physical activity levels, health, community integration, and social participation of people with mobility impairments. METHODS: based on responses to a participation survey, respondents, located primarily in the Midwestern United States, were divided into 3 physical activity groups: high, low, and inactive. We chose a purposeful sample of 604 people with mobility limitations who had a diagnosis of spinal cord injury, multiple sclerosis, cerebral palsy, stroke, or poliomyelitis. The Participation Survey/Mobility (PARTS/M) was used to measure participation in 6 domains and 20 different activities, the Physical Activity and Health Status (SF-36) was used to measure health and quality of life, and the Reintegration to Normal Living Index (RNL) was used to measure integration into the community. RESULTS: people with mobility impairments who were identified as having a high level of physical activity reported greater participation, better health, and a higher level of reintegration to normal community living compared with participants who described their physical activity level as low or inactive. CONCLUSION: positive health status and superior community participation were found in a high physical activity group compared with low active or inactive groups of people with mobility impairments and limitations.

A subjective measure of environmental facilitators and barriers to participation for people with mobility limitations.

PURPOSE: The aim of this paper is to describe the development and psychometric properties of a self-report survey of environmental facilitators and barriers to participation by people with mobility impairments. METHOD: A measure called the Facilitators And Barriers Survey of environmental influences on participation among people with lower limb Mobility impairments and limitations (FABS/M) was developed using items based on focus groups to ensure content validity. Discriminant validity was assessed on 604 individuals who completed the FABS/M once. Internal consistency and test-retest reliabilities were based on 371 individuals who completed two surveys. RESULTS: The FABS/M includes 61 questions, 133 items and six domains including the type of primary mobility device; built features of homes; built and natural features in the community; community destination access; community facilities access; community support network. Environmental items are scored for the frequency of encounter and the magnitude of influence on their participation. The internal consistencies and the test-retest reliabilities of the domains of the FABS/M ranged from low to moderate. The discriminant validity of domains differed for device and diagnostic groups. CONCLUSION. The FABS/M joins the MQE and the CHIEF as another subjective measure for use in assessing environmental features important for understanding participation. The FABS can be used to assess the influence of environmental interventions at the individual and community levels of analysis. The type of primary mobility device that is used can be related to reported environmental barriers. Community-based improvements in built features, access to destinations, access to facilities and augmented support networks can be tracked through the reports of people with mobility impairments.

Assessment of segregation potential of powder blends.

Pharmaceutical blends consist of several components each with its own unique characteristics, with different size, shape, density, and particle-particle interactions. With so many degrees of complexity, prediction of segregation behavior becomes intractable. The objective of this study was to develop a segregation test method or a segregation tool that would assess the segregation potential of blends. Literature reports generally seek to predict the segregation behavior based on only one mechanism by which the segregation occurs, primarily sifting or fluidization. This study makes an attempt to combine both of these mechanisms by which segregation occurs. A test is developed and used to assess the segregation behavior of blends at large scale and compare the content uniformity results of tablets with the results of the segregation test. The segregation testing model was successful in predicting the segregation tendency of the formulation and also in rank ordering large scale formulation blends based on their segregation potential. A segregation risk classification system is proposed to assess the potential of segregation at large scale.