Functional Outcomes Associated With Adaptive Seating Interventions in Children and Youth With Wheeled Mobility Needs

Archives of Physical Medicine and Rehabilitation journal homepage: www.archives-pmr.org Archives of Physical Medicine and Rehabilitation 2014;95:825-31

ORIGINAL ARTICLE

Functional Outcomes Associated With Adaptive Seating Interventions in Children and Youth With Wheeled Mobility Needs Stephen E. Ryan, PhD, PEng,a,b,c Bonita Sawatzky, PhD,d Kent A. Campbell, PhD,b,c,e Patricia J. Rigby, PhD, OTReg(Ont),b,c Kathleen Montpetit, MScOT,f Lori Roxborough, MSc, OT, PT,g Patricia D. McKeever, PhDa,h From aBloorview Research Institute, Holland Bloorview Kids Rehabilitation Hospital, Toronto, ON; bDepartment of Occupational Science and Occupational Therapy, University of Toronto, Toronto, ON; cGraduate Department of Rehabilitation Sciences, University of Toronto, Toronto, ON; dDepartment of Orthopaedics, University of British Columbia, Vancouver, BC; eDalla Lana School of Public Health, University of Toronto, Toronto, ON; fShriners Hospitals for ChildreneCanada, Montreal, QC; gSunny Hill Health Centre for Children, Vancouver, BC; and hLawrence S. Bloomberg, Faculty of Nursing, University of Toronto, Toronto, ON, Canada.

Abstract Objective: To determine the parent-reported functional outcomes associated with adaptive seating devices for wheeled mobility devices used by young people aged 1 to 17 years. Design: Longitudinal case series. Setting: Homes of participating parents. Participants: Parents (NZ70, 63 mothers, 6 fathers, 1 grandmother) who had children with adaptive seating needs. Intervention: Adaptive seating system for wheeled mobility devices. Main Outcome Measure: Family Impact of Assistive Technology Scale for Adaptive Seating (FIATS-AS). Results: All parents completed the FIATS-AS 4 timesd2 times before and 2 times after their child received a new adaptive seating system. Mixed-design analysis of variance did not detect significant mean differences among the FIATS-AS scores measured at baseline and 2 and 8 months after receiving the seating system (F2,134Z.22, PZ.81). However, the FIATS-AS detected a significant interaction between age cohort and interview time (F4,134Z4.5, P<.001, partial h2Z.16). Post hoc testing confirmed that 8 months after receiving the seating system was associated with a large improvement in child and family functioning for children <4 years, maintenance of functioning for children between 4 and 12 years, and a moderate decline in functioning for youth between 13 and 17 years. Conclusions: Adaptive seating interventions for wheeled mobility devices are associated with functional changes in the lives of children and their families that interact inversely with age. Future controlled longitudinal studies could provide further empirical evidence of functional changes in the lives of children and their families after the introduction and long-term use of specific adaptive seating interventions. Archives of Physical Medicine and Rehabilitation 2014;95:825-31 ª 2014 by the American Congress of Rehabilitation Medicine

Assistive technology (AT) devices are widely used to optimize functional performance for children and youth with physical Supported by the Canadian Institutes of Health Research (grant no. PCY-86886), Holland Bloorview Kids Rehabilitation Hospital Foundation, Child Health BC, and BC Child and Youth Health Research Network. No commercial party having a direct financial interest in the results of the research supporting this article has or will confer a benefit on the authors or on any organization with which the authors are associated.

disabilities. However, the impact of specific AT interventions lacks convincing empirical evidence.1,2 In part, the challenge for AT researchers as evidence generators has been the lack of AT-specific measurement models and tools that detect important and meaningful AT outcomes. The Consortium for Assistive Technology Outcomes Research (CATOR) has conceptualized a useful framework to inform the development of AT device-specific outcome models.3 In particular, the CATOR outcomes framework provides

0003-9993/13/$36 - see front matter ª 2014 by the American Congress of Rehabilitation Medicine http://dx.doi.org/10.1016/j.apmr.2013.09.001

826 a useful foundation to understand health outcomes of adaptive seating interventions for children with seating and wheeled mobility needs. Adaptive seating devices are often provided to enhance postural stability and thereby improve volitional arm and hand function, and avoid spastic postures in children with disabilities.4 Pediatric seating therapists typically assess children’s needs and recommend seating interventions that promote proper positioning and seated stability to enhance the functional performance of personal care, play, social interaction, and wheelchair propulsion.4 Further, they prescribe custom seating technologies to help reduce the risk of pressure ulcers5 and the progression of deformities.6 Because seating systems for wheeled mobility devices are costly for government funders, social service agencies, and families, clinical services need to measure and monitor functional outcomes to ensure that these resources are used judiciously.7-9 Our research team developed the Family Impact of Assistive Technology Scale for Adaptive Seating (FIATS-AS).10,11 The FIATS-AS is a 64-item, parent-report questionnaire that measures the effects of adaptive seating interventions on the lives of children and their families. Parents indicate their degree of agreement with items on a 7-point Likert scale. Items are assigned to 1 of 8 dimensions (subscales), whose mean ratings are summed to provide an overall level of child and family functioning in areas that may be influenced by adaptive seating interventions. The FIATS-AS measures aspects of child and parent wellness, including child contentment, parental concern for child safety, and caregiver burden. Other dimensions tap into aspects of child activity and participation, such as the extent to which the child can perform activities independently, whether the child has control over their own actions, and whether the child takes part in social situations. We demonstrated the content validity and face validity of the FIATS-AS10 and completed a study involving 50 parents of preschoolers with cerebral palsy to show that the FIATS-AS had acceptable internal consistency and excellent test-retest reliability.11 Further, we demonstrated that the FIATS-AS could detect an important, positive change in the lives of the child and family when young children who could not sit independently used special purpose seating devices at home for only 6 weeks.12 In the study reported here, we expanded the utility of the measure by examining its ability to detect important changes in the lives of children and their families after the use of new adaptive seating systems. This study was designed to answer the primary research question: “Are important functional changes in the FIATSAS detected for young people, aged 1 year to 17 years, and their families during the 8 months after the provision of a new adaptive seating system for a wheeled mobility device?” Further, we decided a priori to estimate the functional impact of adaptive seating systems across 3 age cohortsd young children (1e3y), preschool/ school age children (4e12y), and adolescents (13e17y)das recommended in an overview of adaptive seating systematic reviews.2

List of abbreviations: ANOVA analysis of variance AT assistive technology CATOR Consortium for Assistive Technology Outcomes Research FIATS-AS Family Impact of Assistive Technology Scale for Adaptive Seating GMFCS Gross Motor Function Classification System HUTCH home use of technology for children

S.E. Ryan et al As a secondary objective, we estimated the internal consistency and test-retest reliability of the FIATS-AS to confirm earlier findings.11

Methods Seventy parents participated as part of a larger study involving 94 parents whose children had wheeled mobility needs. The larger study was designed to estimate the reliability and examine the convergent construct validity of the FIATS-AS. We also conducted a linguistic validation and reliability substudy with a different cohort of 36 French-speaking parents to confirm the measurement equivalence of a French version of the FIATS-AS.13 For the substudy reported here, we chose a repeated-measures, within-subjects design to examine changes in child and family outcomes after the introduction and use of new adaptive seating devices. We received ethical approval for this study from institutional research ethics boards and committees at our coordinating institution and at each recruitment site.

Participants We invited mothers, fathers, or other primary caregivers (hereafter referred to as parents) of children and youth between the ages of 1 and 17 years, 11 months who had been assessed to receive a new adaptive seating system for a wheeled mobility device through 1 of 12 participating rehabilitation services based in Canada’s 3 most populous provinces: Ontario, Quebec, and British Columbia. Wheelchair seating systems were considered new if a back and seat would be provided for the first time, or if they would be entirely replaced because of the child’s growth or a change in postural control. Wheeled mobility bases included specialty strollers, manual wheelchairs, and power wheelchairs for everyday mobility at home and in the community. Parents were eligible if they reported providing at least 5 hours of direct care daily for their child and had the ability to read and understand English and/ or French. Only 1 parent was recruited per child.

Sampling procedure In each of the 12 sites, seating practitioners introduced the research study to parents after determining that the child needed a new seating system. The site research therapist provided interested parents with information about the study after confirming their basic eligibility. They sought consent to participate after a screening phone call or meeting in 1 of the clinics. Of the 116 parents telephoned, 15 parents declined, 5 were unreachable, and 2 were deemed ineligible because the children no longer needed a new seating system. Parents who agreed to participate provided signed consent. Ninety-four parents took part in the larger reliability and validity study, and 70 of these parents provided longitudinal data to answer the primary research question.

Protocol Research investigators trained and provided written guidelines to 11 research therapists (10 occupational therapists and 1 physical therapist) to ensure consistency in appointment scheduling and rigor in measurement administration and data collection. Each recruitment site had up to 3 research therapists available to conduct interviews. Table 1 outlines the appointment schedule, measures, and measurement purposes. Site research therapists scheduled 4 www.archives-pmr.org

Adaptive seating outcomes in children

827

interviews with each parentd1 face-to-face interview and 3 phone interviews. Participants chose to have the initial face-to-face interview (baseline 1) in either their home or the child’s rehabilitation center. The second interview (baseline 2) occurred 2 to 3 weeks after the first interview. Because our earlier research showed that an accommodation period of at least 6 weeks allowed sufficient time for families to establish regular patterns of seating device use,12 the next interview (follow-up 1) was scheduled for 2 months after the child had received the new wheelchair seating system. The final interview (follow-up 2) was scheduled 6 months later to provide additional data about the longer-term effects of wheelchair seating system use, as recommended in the CATOR framework.3

Measurement In addition to completing the FIATS-AS, therapists recorded parent responses for the home environment interview, Gross Motor Function Classification System (GMFCS), and the home use of technology for children (HUTCH) diary during the baseline 1 and follow-up 2 interviews. These 3 measures provided contextual profile of participating families, their home environment, and the types of AT devices children used at home during the study to aid in the interpretation of our primary findings. The home environment interview was designed for the study to capture information about the child (age, schooling), family (number of people in household, number of siblings), social support (amount of formal/informal caregiver support), usual methods used for the child’s positioning and mobility within the home, and other environments (home visitability14 and motor vehicle accessibility). The GMFCS is a 5-level categorical scale with acceptable reliability and validity.15,16 Although this system was developed for children with cerebral palsy, the GMFCS categorizes functional motor level by what a child does at home and in the community. Thus, we recorded the GMFCS level rather than the diagnoses to categorize the functional levels of children whose parents met our inclusion criteria. The HUTCH diary recorded the child’s use of home seating, positioning, and mobility-related devices.17 This diary consists of 8 assistive device categories and scales to indicate the number of hours per day the child used devices in each category over the previous week. The HUTCH diary has excellent test-retest reliability (intraclass correlation coefficient >.90) and utility when completed by parents of children who use AT devices.17

FIATS-AS for the first, third, and fourth test administrations using a 2-way mixed analysis of variance (ANOVA). Children were assigned to 1 of 3 age cohorts based on their ages at the initial parent interview. We applied a general linear model procedure for repeated measures using IBM SPSS Statistics version 19a for this analysis. The type I error probability was set as alphaZ.05 (2 sided) for the mixed ANOVA, and a Bonferroni correction was used for multiple statistical testing during post hoc analyses. We considered an important, meaningful effect size to be a magnitude of at least 50% of the SD of the mean difference scores using a distribution-based approach proposed by measurement authorities,18,19 and as adopted in our previous study.12 Based on previous FIATS-AS change data,12 a sample size of 70 parents provided a power in excess of 90% for a type I error of alphaZ.05 (2 sided). Data from the first 2 administrations of the FIATS-AS estimated internal consistency (baseline 1) and 2-week test-retest reliability of the total scale (baselines 1 and 2). We provided a contextual profile of participants and their home environment using relevant descriptive statistics for the home environment, GMFCS, and HUTCH.

Results Demographics Seventy parents (63 mothers, 6 fathers, 1 grandmother) of children with wheeled mobility needs participated. Fifty one had at least 2 children, 1 of whom was a child who met our inclusion criteria. The mean age  SD of the children with seating needs was 10 years 6 months  4 years 10 months (range, 1y 7moe17y 11 mo) at the first interview. Of these, 57 children were nonambulatory and 13 were ambulatory (table 2). The sex distribution was 41 boys and 29 girls. Table 3 provides a profile of the participants’ families, children, and home visitability at baseline. Parents used a variety of devices for positioning and mobilizing the children for different durations. Although all children used wheeled mobility devices, only one third used them >6 hours per day. Most parents reported that their children regularly used special bath seats, toilet seats, or activity seats, such as floor sitters and high chairs, for up to 2 hours per day. Wheeled walkers (31%) and standing frames (13%) were used less frequently for shorter periods during the day. The frequency and duration of use of alternative devices for positioning and mobility between the baseline 1 interview and the follow-up 2 interview remained generally stable.

Statistical analysis

Interview intervals

We estimated the effect of the new adaptive seating systems and tested the interaction of age over time by comparing the mean scores for the

The predicted funding approval and dispense dates for the new seating systems lacked consistency, and interview dates were often

Table 1

Administration schedule, measures, and measurement purpose for baseline and intervention phases

Category

Baseline 1

Baseline 2

Follow-Up 1

Follow-Up 2

Interview type Timing

Face-to-face >3wk before receipt of new wheelchair seating Home Environment Interview GMFCS HUTCH FIATS-AS Baseline measure and internal consistency

Phone 2e3wk after first home visit FIATS-AS

Phone 2mo after receipt of new wheelchair seating FIATS-AS

Test-retest reliability

Responsiveness (shorter term)

Phone 7e8mo after receipt of new wheelchair seating Home Environment Interview GMFCS HUTCH FIATS-AS Responsiveness (longer term)

Measures

Measurement purpose

www.archives-pmr.org

828 Table 2

S.E. Ryan et al Distribution of children by GMFCS level and age group Age Group

GMFCS Level

1e3y

4e12y

13e17y

Total

I II III IV V Total

1 2 1 2 4 10

0 0 5 22 8 35

0 1 3 9 12 25

1 3 9 33 24 70

NOTE. Children in levels I, II, and III are ambulatory; children in levels IV and V are nonambulatory.

Discussion The FIATS-AS showed large, important functional improvement in the lives of children <4 years of age and their families 8 months after receiving a new adaptive seating device. Conversely, we found a moderate, meaningful decline in child and family functioning in youth aged 13 to 17 years over the same interval. We found no measureable functional change in the lives of children

Table 3 Profiles of participants’ families, children, and home environment at baseline Family profile (NZ70) Variable

influenced by the schedules of busy families. Thus, the mean interval  SD between the baseline 1 interview and follow-up 1 was 5.52.8 months. However, the mean interval  SD between the seating system dispensing date and follow-up 1 was 2.21.6 months; between the seating dispensing date and follow-up 2, the mean interval  SD was 7.72 months.

Statistic

No. of adults in home No. of children in home Hours per week of in-home support for child Working hours per week by parent outside home No. who have in-home support No. who work outside home

Reliability Internal consistency for the FIATS-AS was acceptable (Cronbach aZ.89), and test-retest reliability was high (intraclass correlation coefficientZ.96; 95% confidence interval, .94e.98). Seven of 8 subscales had Cronbach alphas that were within a range of 0.7 to 0.9. The remaining subscale (family and social interaction) had 4 items and a Cronbach alpha of 0.5. Tables 4 and 5 provide mean scores  SD for the FIATS-AS by age cohort for baseline 1 and both follow-up interviews.

Effect of intervention We used a mixed-design ANOVA to assess the impact of the new wheelchair seating intervention for the 3 age cohorts using the FIATS-AS across 3 test administrations (baseline 1, follow-up 1, follow-up 2). With respect to the primary research question, we did not detect significant main effects for time (F2,134Z.22, PZ.81). Similarly, we found no significant main effect for age (F2,67Z.52, PZ.16). However, the FIATS-AS detected a significant interaction among age cohorts and time (F4,134Z4.5, P<.001, partial h2Z.16) (fig 1). Paired t tests confirmed a significant and positive mean difference in overall FIATS-AS scores for children in the 1- to 3-year-old age group (t9Z3.27, PZ.01), no significant mean differences for children in the 4- to 12-year-old age group (t34Z.26, PZ.79), and significant and negative mean differences in overall scores for youth in the 13- to 17-year-old age group (t24Ze3.47, PZ.002) when we tested mean change scores between baseline and follow-up 2 interviews. The magnitudes of the mean difference scores were 47% and 62% of the SD of mean change scores for the youngest and oldest cohorts, respectively, at follow-up 1 (see table 4). The magnitudes of the mean difference scores were 103% and 67% of the SD of the mean change scores for the youngest and oldest cohorts, respectively, at follow-up 2 (see table 5).

Mean  SD 2.41.4 2.41.3 17.316.4 29.012.6 n (%) 26 (37.7) 39 (56.5)

Child with adaptive seating needs profile (nZ69*) n (%) Schooling Not at daycare or nursery school Nursery school or kindergarten Grades 1e8 Grades 9e12 Usual home mobility methods Carried or pushed by an adult or other family member in a stroller, wheelchair, or other similar equipment Rolls, creeps, crawls or takes steps with or without assistance Propels self in regular or power wheelchair Combination of above and other methods Usual home positioning methods Sits on chair with/without extra support Sits in wheeled device Lying on floor or bed Combination of above and other methods

10 10 34 15

(14.5) (14.5) (49.3) (21.7)

29 (42.0)

16 (23.2) 11 (15.9) 13 (18.8) 26 19 13 11

(37.7) (27.5) (18.8) (15.9)

Home visitability and vehicle accessibility (nZ69*) n (%) No. of participants who have. .a level, no-step doorway entrance along accessible route into the home .doorways inside the home with clear passage for the child to get around the home .a wheelchair accessible bathroom on your main floor .other rooms in home where the child cannot (or would not be able to) go in a wheelchair .a motor vehicle capable of transporting the child in a wheelchair

30 (43.5) 5 (7.2) 35 (50.7) 22 (31.9) 31 (44.9)

* One participant had partial missing data for the home environment interview.

www.archives-pmr.org

Adaptive seating outcomes in children Table 4

829

Descriptive and 95% CIs for difference results for the FIATS-AS at baseline and follow-up 1 by age cohort

Age Cohort

n

Interview

Mean  SD

1e3y

10

Baseline 1

34.74.0

35

Follow-up 1 Baseline 1

37.54.9 34.87.7

25

Follow-up 1 Baseline 1

34.77.4 35.97.7

Follow-up 1

33.68.8

4e12y

13e17y

Difference of Means

SD of Difference

Ratio of Difference to SD of Difference

95% CI of Difference

2.7

5.8

.47

1.5 to 6.9

0.1

3.5

.03

1.3 to 1.1

2.3

3.7

.62

3.9 to

0.8

NOTE. Mean scores can range from 8 (low child and family functioning) to 56 (high child and family functioning). Abbreviation: CI, confidence interval.

and their families in children between the ages of 4 and 12 years during the same period. The FIATS-AS detected similar, but less important, changes in child and family functioning in the youngest and oldest age cohorts 2 months after the introduction of the adaptive seating system. No overall change in child and family functioning in the school-aged cohort was evident over the shorter follow-up period. Our finding of a meaningful, positive impact in child and family functioning for 1- to 3-year-olds was consistent with our earlier study of the impact of special purpose seating devices on young children with cerebral palsy.12 Ours is the second study using the FIATS-AS that has demonstrated an important positive impact in functional performance for young children following the introduction of adaptive seating devices. An exploratory review of subscale contributions to overall change scores suggests a trend toward functional gains in all but 1 dimension (caregiver relief) of the FIATS-AS. Growth motor curves show a trend toward improved gross motor skills in children with ambulatory and nonambulatory cerebral palsy until after ages 3 to 4 years.20 This suggests that positive changes in FIATS-AS scores are associated with the natural development of gross motor skills. Similarly, we found a maintenance of functional performance in children aged 4 to 12 years up to 8 months after they had received a new seating system, corresponding to a prognostic plateau in gross motor skills for children with cerebral palsy at all GMFCS levels beyond 6 years of age.20 Despite the apparent leveling in functional performance overall, an exploratory review of FIATS-AS subscores suggests emerging gains in key dimensions of Table 5

Descriptive and 95% CIs for difference results for the FIATS-AS at baseline and follow-up 2 by age cohort

Age Cohort

n

Interview

Mean  SD

1e3y

10

Baseline

34.74.0

35

Follow-up 2 Baseline

38.52.9 34.87.7

25

Follow-up 2 Baseline

35.08.0 35.97.7

Follow-up 2

33.08.4

4e12y

13e17y

child functioning (autonomy, doing activities, contentment) between baseline 1 and follow-up 2 interviews. Interestingly, the decline in functional performance measured among youth prevailed despite the prediction of motor skill stability in children with cerebral palsy up to age 15 years.20 Because study participants included both those with nonprogressive disabilities and those with degenerative disabilities, this may have contributed to this reported decline in functional performance. An exploratory review of FIATS-AS subscores suggests a greater relative decline in child autonomy and social interaction compounded by an increasing need for caregiver relief contributed to the overall decline in FIATS-AS total scores. We hypothesized that home modifications and the introduction of other types of seating and positioning technologies could influence outcomes measured on the FIATS-AS. Interestingly, parents reported that their children did not rely exclusively on the adaptive seating device for positioning in and around the home. Children regularly used different positioning technologies throughout the day. The variety of seating and positioning devices included floor sitters, standers, bath seats, adaptive toilet seats, and simple adaptations to couches and other home furniture. The broad range of seating and positioning devices used by children with disabilities in home environments is consistent with the findings of others.17,21,22 However, our analyses of paired data from the home environment interview and the HUTCH diary at the baseline and at second follow-up interviews suggest that home accessibility and the frequency and intensity of use of other seating and positioning technologies remained generally stable over the course of the study.

Abbreviation: CI, confidence interval.

www.archives-pmr.org

Difference of Means

SD of Difference

Ratio of Difference to SD of Difference

95% CI of Difference

3.8

3.7

1.03

1.2 to 6.4

0.2

3.7

.04

1.1 to 1.4

3.0

4.3

.70

4.7 to

1.2

830

S.E. Ryan et al

Supplier

39 38

a. IBM Corporation, 1 New Orchard Rd, Armonk, NY, 10504e 1722.

FIATS-AS Score

37 36 35

Keywords

34 33

Family; Outcome assessment (health care); Rehabilitation; Selfhelp devices; Wheelchairs

32 31 30 Baseline 1 1-3 years

Follow-up 1 4-12 years

Follow-up 2 13-18 years

Fig 1 Mean FIATS-AS scores for baseline 1, follow-up 1, and followup 2 interviews by age cohort.

Corresponding author Stephen E. Ryan, PhD, PEng, Bloorview Research Institute, Holland Bloorview Kids Rehabilitation Hospital, 150 Kilgour Rd, Toronto, ON, Canada M4G 1R8. E-mail address: sryan@ hollandbloorview.ca.

Study limitations

Acknowledgments Our findings may have been biased by a sampling strategy that resulted in the recruitment of families who may not be representative of the population of families who have children with adaptive seating needs. We had broad eligibility criteria that included children who were either ambulatory or nonambulatory. However, >80% of our sample included nonambulatory children who relied on adaptive seating systems and wheeled mobility devices more than their ambulatory peers. Measurement authorities recommend rigorous AT intervention specification and treatment fidelity to fully understand the AT outcomes.23 We defined the intervention solely as the provision of a new seat and back for a wheeled mobility device. Some children had received their first adaptive seating system, whereas others received a new seating system to replace an existing one because of growth or a change in medical condition. We argued that all children used alternative forms of seating prior to receiving their first adaptive seating system, as evidenced from the baseline HUTCH findings. However, it is possible that parents perceived a difference in impact for first-time versus replacement adaptive seating devices. Further, the diversity of clinical sites and complexity of child seating needs may have resulted in the selection of seating technologies adjusted, customized, and adapted in both novel and different ways. Disentangling the contribution of clinical service support from the new adaptive seating device was beyond the scope of our study, but would be important to explore in future research.

Conclusions We found emerging empirical evidence that adaptive seating interventions for wheeled mobility devices are associated with functional changes in the lives of children and their families that interact inversely with age. Future research should explore the multidimensional effects of specific adaptive seating devices, interventions, and treatments within precise age cohorts over different time intervals. Research designs, such as single-subject research designs, interrupted time series, and observational studies with age-matched controls, will provide higher levels of evidence supporting the provision of adaptive seating interventions for children with wheeled mobility needs.

We thank our research team members (Julie Chiba Branson, Helen Cohen, Vasiliki Darsaklis, Barb Easton, Debbie Field, Marie-Elaine Lafrance, Noemi Dahan Oliel, Ann MacNeish, Deana Mercier, and Joan Walker), who collected data and contributed to data interpretation. We also thank the decision maker team members (Ian Lowe, Shirley Meaning, and Joan Stevens), who provided practical contextual advice during the conduct of the study.

References 1. Henderson S, Skelton H, Rosenbaum P. Assistive devices for children with functional impairments: impact on child and caregiver function. Dev Med Child Neurol 2007;50:89-98. 2. Ryan SE. An overview of systematic reviews of adaptive seating interventions for children with cerebral palsy: where do we go from here? Disabil Rehabil Assist Technol 2012;7:104-11. 3. Fuhrer MJ, Jutai J, Scherer MJ, DeRuyter F. A framework for the conceptual modelling of assistive technology device outcomes. Disabil Rehabil 2003;5:1243-51. 4. Cook AM, Miller Polgar J. Cook and Hussey’s principles of assistive technology. St Louis: Elsevier; 2008. 5. Samaniego IA. A sore spot in pediatrics: risk factors for pressure ulcers. Pediatr Nurs 2003;29:278-82. 6. Bredhult A, Landstrom A, Myhr U. Windswept hip syndrome e a literature review. Nordisk Fysioterapi 2001;5:135-42. 7. Fuhrer MJ. Assessing the efficacy, effectiveness, and costeffectiveness of assistive technology interventions for enhancing mobility. Disabil Rehabil Assist Technol 2007;2:149-58. 8. Harris F, Sprigle S. Cost analyses in assistive technology research. Disabil Rehabil Assist Technol 2003;15:16-27. 9. Jacobs P, Haily D, Jones A. Economic evaluation for assistive technology policy decisions. J Disabil Pol Stud 2003;14:119-25. 10. Ryan SE, Campbell KA, Rigby P, Germon B, Chan B, Hubley D. Development of the new family impact of assistive technology scale. Int J Rehabil Res 2006;29:195-200. 11. Ryan SE, Campbell KA, Rigby PJ. Reliability of the family impact of assistive technology scale. Arch Phys Med Rehabil 2007;88: 1436-40. 12. Ryan SE, Campbell KA, Rigby PJ, Fishbein-Germon B, Hubley D, Chan B. The impact of adaptive seating devices on the lives of young children with cerebral palsy and their families. Arch Phys Med Rehabil 2009;90:27-33.

www.archives-pmr.org

Adaptive seating outcomes in children 13. Ryan SE, Montpetit K, Darsaklis VB, et al. Measurement of assistive technology outcomes in children of French-speaking families. In: Canadian Association of Paediatric Health Centres, editor. Abstracts: The 2011 Canadian Association of Paediatric Health Centres (CAPHC) Conference; 2011 Oct 16e19; Ottawa (Canada). Vancouver: CAPHC Conference Secretariat; 2011. p 10. 14. Canadian Centre on Disability Studies. Welcome to Visibility Canada. Available at: http://www.visitablehousingcanada.com/index.html. Accessed February 27, 2013. 15. Palisano RD, Rosenbaum P, Walter S, Russell D, Wood E, Galuppi B. Development and reliability of a system to classify gross motor function in children with cerebral palsy. Dev Med Child Neurol 1997; 39:214-23. 16. Morris C, Galuppi BE, Rosenbaum PL. Reliability of family report for the Gross Motor Function Classification System. Dev Med Child Neurol 2004;46:455-60. 17. Ryan SE, Campbell KA. Evaluation of a parent-report diary of the home use of assistive devices by young children with cerebral palsy. Disabil Rehabil Assist Technol 2009;4:189-97.

www.archives-pmr.org

831 18. Norman GR, Sloan JA, Wyrwich KW. Interpretation of changes in health-related quality of life: the remarkable universality of half a standard deviation. Med Care 2003;41:582-92. 19. Revicki D, Hays RD, Cella D, Sloan J. Recommended methods for determining responsiveness and minimally important differences for patient-reported outcomes. J Clin Epidemiol 2008;61:102-9. 20. Rosenbaum P, Walter SD, Hanna SE, et al. Prognosis for gross motor function in cerebral palsy: creation of motor development curves. JAMA 2002;288:1357-63. 21. Ostensjo S, Carlberg EB, Vollestad NK. The use and impact of assistive devices and other environmental modifications on everyday activities and care in young children with cerebral palsy. Disabil Rehabil 2005;27:849-61. 22. Korpela R, Seppanen RL, Koivikko M. Technical aids for daily activities: a regional survey of 204 disabled children. Dev Med Child Neurol 1992;11:985-98. 23. Jutai JW, Fuhrer MJ, Demers L, Scherer MJ, DeRuyter F. Toward a taxonomy of assistive technology outcomes. Am J Phys Med Rehabil 2005;84:294-302.