Abstract
Objective
The objective of this study was to finalise the development of the Young Disability Questionnaire (YDQ-spine) to measure the consequences of neck, midback and low back pain, relevant for schoolchildren aged 9–12 years.
Design
A cross-sectional field test of the YDQ-spine was carried out.
Setting
Danish primary schools.
Participants
Children aged 9–12 years from all Danish schools were invited to complete the questionnaire.
Methods
Eight hundred and seventy-three schools were invited to participate. Consenting schools received information material, instructions and a link to an electronic version of the prefinal YDQ-spine. Local teachers distributed the electronic YDQ-spine to children aged 9–12 years. Descriptive statistics and item characteristics were carried out. Item reduction was performed using partial interitem correlations (scrutinising correlations>0.3) and factor analyses (items loading>0.3 were retained) to eliminate redundant items and to obtain insight into the structure of the questionnaire.
Results
A total of 768 children from 20 schools answered of the questionnaire and 280 fulfilled the inclusion criteria of having back and/or neck pain (36%). Multisite pain was reported by 38%. Partial interitem correlations and factor analyses resulted in elimination of four items which were considered redundant leaving 24 items in the final YDQ-spine with an optional section on what matters most to the child. The factor analyses showed a two-factor structure with a physical component (13 items) and a psychosocial component (10 items) in addition to one standalone item (sleep).
Conclusion
The YDQ-spine is a novel questionnaire with satisfactory content validity measuring physical and psychosocial components (including sleep disturbances) of spinal pain in children aged 9–12 years. It also offers an optional section on what matters most to the child allowing targeted care in clinical practice.
Keywords: back pain, pain management, paediatrics, rehabilitation medicine
STRENGTHS AND LIMITATIONS OF THE STUDY.
A broad sample of school children aged 9–12 years who experienced more than trivial spinal pain were included in the development of the Young Disability Questionnaire.
Item reduction procedures were performed using partial interitem correlations.
Questionnaire structure was analysed through factor analytical techniques.
Further validation including the measurement properties of reliability, responsiveness and interpretation is required.
Introduction
Low back pain is one of the main contributors to the global burden of disease among the adult population causing disability and loss of work capacity.1 2 Several studies have concluded that the younger population also is affected by spinal pain3–5 and that children and adolescents with spinal pain are likely to continue their spinal pain into adulthood.6–8 The consequences among children and adolescents with recurrent low back pain are serious with 31% having skipped sports and other physical activities and 26% having been absent from school.9 10 Therefore, in addition to the increased risk of spinal pain, there are several potential long term consequences, for example, overweight.11
Measuring the consequences of spinal pain in children and adolescents requires well-developed patient-reported outcome measures (PROMs).12 A plethora of back-specific and neck-specific PROMs exist for the adult population which are particularly good at measuring how a health condition affects a person’s life.13 14 However, relevant validated PROMs for children and adolescents with low back, middle back or neck pain are limited, as research regarding specific consequences of spinal pain related to the daily living among younger populations is scarce.4
Consequently, a three-phase research programme was launched at the University of Southern Denmark. Phase 1 identified domains concerning consequences of spinal pain that mattered to children by interviewing Danish school children aged 9–12 with back pain.15 Phase 2 was the developmental phase, where the first version of the Young Disability Questionnaire-Spine (YDQ-spine) was developed by comparing the interview domains from phase 1 with existing validated questionnaire items developed for children.16 The YDQ-spine was pilot-tested twice to ensure comprehension within the population of Danish 9–12-year-old school children. The present study (phase 3 aims to finalise the development of the YDQ-spine by performing a field test, including item characteristics, partial interitem analysis and factor analyses to eliminate redundant items and obtain insight into the structure of the questionnaire. Reliability of the final model was established.
Methods
The field test of the YDQ-spine was carried out anonymously by inviting school children in the third to sixth grade in Denmark to participate. The first version of the YDQ-spine16 was constructed in SurveyXact17 for distribution.
Participating schools
Contact information for the schools was found on the website of the Ministry of Education, where all registered schools appear. E-mails with an invitation and description of the project were sent to 873 public and private schools across the country. Information material and instructions for the teachers, as well as information for the parents, were sent to the schools that agreed to participate. To increase the chance of recruitment success, personal contacts at schools were also explored, following the standard mail to all schools. These contacts received the same information. It was emphasised that the children or their parents at any time could withdraw from the project. The electronic version of the YDQ-spine was made anonymous by only asking for the grade and distributed as a link by e-mail. Five different links were created, one for each region in Denmark, to ensure anonymity for the participating schools. The teachers or headmasters distributed the links. All questionnaires were required to be completed during school hours to avoid the influence of parents.
Participants
The target population for the questionnaire was children aged 9–12 years, which corresponds to third to sixth grade, attending private or public schools in Denmark. The age limits were set according to the prior studies in the research programme,15 16 where the lower age limit was set to 9 years to ensure a certain level of linguistic and cognitive ability to understand and reflect on themselves.18 The upper age limit was set to 12 years to avoid the growth spurt and puberty, which has been shown to have an influence on back pain.19–21
Sample size
The sample size for the exploratory factor analyses (EFA) was estimated with a subject:item ratio of between 8:10 and 10:1 ensuring stability of the variance–covariance matrix.22 23 Exploring 28 items, this equates to a sample of 224–280 children. As it has been shown that up to one-third of adolescents are affected by musculoskeletal pain every year,3 the sample was adjusted to include approximately 1000 children to make sure that a minimum of 224 respondents with back or neck pain was obtained.
The survey
The electronic version of YDQ-spine was structured with an initial question where the children had to tick off their grade (third to sixth). This was mandatory and followed by a series of questions (section 1) asking about the frequency and pain intensity of the neck, middle back and low back taken from sections 1–3 of the Young Spine Questionnaire.24 Briefly, frequency was measured asking the question How often have you had pain in the neck/middle of the back/lower back? with the response options of ‘Often’, ‘Once in a while’, ‘Once or twice’ and ‘Never’. Pain intensity was measured using the revised Faces Pain Scale (rFPS)25 which consists of six drawings of children’s facial expressions depicting increasing severity of expressed pain. The rFPS has shown good reliability and validity in children aged 5–12 years.26 If the child fulfilled the inclusion criteria (see inclusion and exclusion criteria), section 2 of the newly developed questionnaire was activated (figure 1). This included 28 questions about consequences of spinal pain with the response options ‘never’, ‘once or twice’, ‘sometimes’, ‘often’ and ‘nearly always’, followed by four items regarding ‘What matters most to the children’ which were answered on a visual analogue scale from 0 to 10. The latter four items focus on the domains ‘That it hurts so much’, ‘That I can’t move around as much as I’d like’, ‘That I can’t spend as much time with my friends’ and ‘That I get sad or angry or can’t concentrate’. The full version of the prefinal YDQ-spine can be found in Meldgaard et al.16
Figure 1.
The inclusion of children in the study. Section 1, prevalence and pain intensity estimates from the Young Spine questionnaire; Section 2, newly developed consequences of spinal pain items. *rFPS, revised Faces Pain Scale.
Inclusion and exclusion criteria
The inclusion criteria were defined as children aged 9–12 years with spinal pain occurring ‘Once in a while’ or ‘Often’ and a pain intensity of ≥face 2 on the rFPS, equivalent to ≥3 on a 10-point numerical rating scale,25 27 to exclude children with only mild/trivial pain.28 Non-Danish-speaking children and schools with a pupil population of >90% non-ethnic Danes were excluded to avoid a language bias.
Statistical analyses
The statistical analyses conform to the COSMIN (COnsensus-based Standards for the selection of health Measurement INstruments) methodology for performing a field test.29 30 Descriptive statistics, including frequency of pain, distribution of grade, region and pain site, were presented to frame the level and distribution of spinal pain among the children. We then performed item reduction procedures by examining the items and partial interitem correlations followed by EFAs of the remaining items. Internal consistency reliability was performed and compared on all models.
Item characteristics
Item characteristics were examined through percentage of missing items and response distributions. We considered <3% missing scores per item as acceptable, whereas >15% was unacceptable and the item removed.30 Items with missing scores between 3% and 15% were kept for later evaluation based on the factor analysis.
Partial interitem correlation
Analysis of partial interitem correlations was performed on the 28 questions about consequences to avoid ambiguous items. High partial interitem correlations (also called response dependence) occur when a response to one item governs the response on another due to similarities in item content or response options.31 32 Item pairs with partial interitem correlation above 0.3 of the average correlation were located, examined and discussed with the purpose of item reduction.32
Exploratory factor analyses
EFA was used to reduce items with no or unclear contribution to the factors and explore the dimensionality of the 28 questions.33 Sampling adequacy was tested using Bartlett’s Test of Sphericity and the Kaiser-Meyer-Olkin (KMO) test. To obtain more meaningful and correlated factors, a principal axis factor analysis using a polychoric correlation matrix combined with an oblique oblimin rotation with Kaiser normalisation was carried out.34 The number of factors to be extracted was examined using: (1) examination of screeplot (eigenvalues>1), (2) parallel analysis and (3) Velicer’s minimum average partial factor retention method (Velicer’s MAP).35 Finally, to improve the factor loading, a stepwise approach was implemented, removing one item at a time. Items with no loadings and a theoretical displacement in the factor components were removed. Factor loadings of >0.3 were considered satisfactory, as these translate to approximately 10% of the variance of the factor.34 Observations with missing answers in all questions were excluded.
Reliability
The internal consistency of each dimension in all factor models was evaluated using Cronbach’s alpha.36 The alpha coefficient is usually well accepted if it is between 0.7 and 0.9.30 37
Descriptive statistics, item analyses, EFAs and reliability were conducted using STATA V.17.38 Partial interitem correlation analysis was explored using RUMM 2030.39
ICF mapping of the final YDQ-spine
The content of the final YDQ-spine version was mapped to the WHO International Classification of Functioning, Disability and Health (ICF) conceptual model.40 The ICF was chosen as it provides a framework for classifying health according to the biopsychosocial model41 describing functioning and disability, as well as contextual factors.42 43 Item content was mapped according to ICF constructs and categories using the online ICF classification tool44 and the ICF manual.45
Patient and public involvement
The methodology follows the COSMIN approach for developing a questionnaire,29 30 and no patients were involved in the design of the study.
Results
Participating schools
A total of 873 public and private schools were invited to the project by e-mail or personal contact. Twenty schools accepted the invitation; eight schools were invited by e-mail and the remaining 12 schools were invited through personal contacts.
Participants
A total of 768 participants with an average of 38.4 participants from each school filled out the questionnaire. Participants from all five regions in Denmark were included with 2 (0.3%) from the Region of Northern Jutland, 318 (41.4%) from the Region of Central Jutland, 219 (28.5%) from the Region of Southern Denmark, 151 (19.7%) from the Region of Zealand and 78 (10.2%) from the Region of the Capital. Representation of the grades were relatively evenly distributed (third grade: 118 (15.4%); fourth grade: 286 (37.2%); fifth grade: 185 (24.1%) and sixth grade: 179 (23.3%).
Of the 768 participants, 280 responses (36%) reported spinal pain as defined by our inclusion criteria. Most children reported neck pain (106, 37.9%), followed by middle back pain (49, 17.5%), and 20 (7.1%) reported low back pain. A total of 105 (37.5%) reported multisite pain, meaning pain in more than one region of the back (table 1).
Table 1.
Regional distribution of back and neck pain in the participants
| Pain site | Region of Northern Jutland, n (%) | Region of Central Jutland, n (%) | Region of Southern Denmark, n (%) | Region of Zealand, n (%) | Region of the Capital, n (%) | Total, n |
| NP | 1 (0.9) | 41 (38.7) | 38 (35.9) | 15 (14.2) | 11 (10.4) | 106 |
| MBP | 0 (0.0) | 18 (36.7) | 13 (26.5) | 13 (26.5) | 5 (10.2) | 49 |
| LBP | 0 (0.0) | 8 (40.0) | 5 (25.0) | 7 (35.0) | 0 (0.0) | 20 |
| MPS | 0 (0.0) | 33 (31.4) | 32 (30.5) | 25 (23.8) | 15 (14.3) | 105 |
| Total | 1 (0.4) | 100 (35.7) | 88 (31.4) | 60 (21.4) | 31 (11.1) | 280 |
LBP, low back pain; MBP, mid back pain; MPS, multiple pain sites; NP, neck pain.
Item characteristics
The percentage of missing scores for the 28 items were gradually increasing with increasing item number equivalent to the time spent on the questionnaire (table 2). Only one item (#1) had missing scores <3%, items #2–#25 ranged between 3.3% and 12.7% and were considered acceptable, and items #26–#28 were ≥12% and considered borderline. Response options ‘Never’ and ‘Once or twice’ were the most frequently used for most items.
Table 2.
Missing scores and distribution of response options of the 28 questions about consequences of spinal pain
| Item (#) | Item content | Missing scores,* N (%) | Distribution across response options, n (%) | ||||
| Never | Once or twice | Once in a while | Often | Almost all the time | |||
| 1 | When I have pain, it is hard to take care of myself (eg, put on clothes, shower) | 7 (2.5) | 163 (59.2) | 61 (22.2) | 36 (13.1) | 7 (2.5) | 1 (0.4) |
| 2 | When I have pain, it is hard to sit with the head bend forward (looking at a phone, homework, etc.) | 17 (6.2) | 60 (21.8) | 67 (24.4) | 81 (29.5) | 30 (10.9) | 20 (7.3) |
| 3 | When I have pain, it is hard to lift something heavy | 20 (7.3) | 86 (31.3) | 68 (24.7) | 54 (19.6) | 36 (13.1) | 11 (4.0) |
| 4 | When I have pain, it is hard to bend forward | 22 (8.0) | 61 (22.2) | 80 (29.1) | 60 (21.8) | 36 (13.1) | 16 (5.8) |
| 5 | When I have pain, it is hard to stand for as long as usual | 12 (4.4) | 117 (42.6) | 61 (22.2) | 59 (21.5) | 15 (5.5) | 11 (4.0) |
| 6 | When I have pain, it is hard to sit for as long as usual | 22 (8.0) | 100 (36.4) | 68 (24.7) | 54 (19.6) | 22 (8.0) | 9 (3.3) |
| 7 | When I have pain, it is hard to walk as well as usual | 28 (10.2) | 106 (38.6) | 69 (25.1) | 49 (17.8) | 16 (5.8) | 7 (2.6) |
| 8 | When I have pain, it is hard to run as well as usual | 24 (8.7) | 60 (21.8) | 63 (22.9) | 68 (24.7) | 41 (14.9) | 19 6.9) |
| 9 | When I have pain, it is hard to do sports as usual | 9 (3.3) | 71 (25.8) | 70 (25.5) | 63 (22.9) | 36 (13.1) | 26 (9.5) |
| 10 | When I have pain, it is hard to play as usual | 20 (7.3) | 98 (35.6) | 70 (25.5) | 52 (18.9) | 22 (8.0) | 13 (4.7) |
| 11 | When I have pain, it is hard to ride a bike | 21 (7.6) | 100 (36.4) | 67 (24.4) | 49 (17.8) | 20 (7.3) | 18 (6.6) |
| 12 | When I have pain, I don’t have as much fun as usual | 10 (3.6) | 63 (22.9) | 73 (26.6) | 64 (23.3) | 40 (14.6) | 25 (9.1) |
| 13 | When I have pain, I become quiet | 23 (8.4) | 100 (36.4) | 69 (25.1) | 46 (16.7) | 27 (9.8) | 10 (3.6) |
| 14 | When I have pain, I can feel more lonely than usual | 22 (8.0) | 157 (57.1) | 40 (14.6) | 33 (12.0) | 17 (6.2) | 6 (2.2) |
| 15 | When I have pain, I am more likely to fall out with others | 23 (8.4) | 145 (52.7) | 51 (18.6) | 29 (10.6) | 12 (4.4) | 15 (5.5) |
| 16 | When I have pain, I get worried about the pain | 13 (4.7) | 109 (39.6) | 74 (26.9) | 56 (20.4) | 15 (5.5) | 8 (2.9) |
| 17 | When I have pain, the pain can make me scared |
24 (8.7) | 144 (52.4) | 57 (20.7) | 29 (10.6) | 13 (4.7) | 8 (2.9) |
| 18 | When I have pain, I get grumpy or annoyed more easily | 24 (8.7) | 70 (25.5) | 72 (26.2) | 53 (19.3) | 34 (12.4) | 22 (8.0) |
| 19 | When I have pain, I get sad or upset more easily | 24 (8.7) | 92 (33.5) | 67 (24.4) | 49 (17.8) | 20 (7.3) | 23 (8.4) |
| 20 | When I have pain, I find it harder to concentrate | 15 (5.5) | 57 (20.7) | 68 (24.7) | 64 (23.3) | 45 16.4) | 26 (9.5) |
| 21 | When I have pain, I stay home from school | 24 (8.7) | 143 (52.0) | 58 (21.1) | 38 (13.8) | 5 (1.8) | 7 (2.6) |
| 22 | When I have pain, I get so tired I cannot do what I usually do | 25 (9.1) | 97 (35.3) | 73 (26.6) | 43 (15.6) | 23 (8.4) | 14 (5.1) |
| 23 | When I have pain, I don’t sleep so well | 28 (10.2) | 63 (22.9) | 58 (21.1) | 62 (22.6) | 33 (12.0) | 31 (11.3) |
| 24 | When I have pain, I have less energy | 30 (10.9) | 66 (24.0) | 59 (21.5) | 53 (19.3) | 41 (14.9) | 26 9.5) |
| 25 | When I have pain, I can do something to ease the pain | 26 (9.5) | 63 (22.9) | 66 (24.0) | 67 (24.4) | 31 (11.3) | 22 (8.0) |
| 26 | When I have pain, it is hard to talk to my mum or dad about it | 33 (12.0) | 161 (58.6) | 38 (13.8) | 21 (7.6) | 12 (4.4) | 10 (3.6) |
| 27 | When I have pain, it is hard to talk to my friends about it | 33 (12.0) | 146 (53.1) | 33 (12.0) | 34 (12.4) | 10 (3.6) | 19 (6.9) |
| 28 | When I have pain, I get treatment (eg, at the GP, chiropractor or physiotherapist) | 35 (12.7) | 152 (55.3) | 41 (14.9) | 26 (9.5) | 9 (3.3) | 12 (4.4) |
*Total number of answered questionnaires=275 (5 responses with no answers).
GP, general practitioner.
The response distributions of the four items regarding ‘What matters most to the children’ are shown in figure 2. Generally, all four domains are important to the children, however, they are weighted differently. The domain of spending time with the friends was the domain that most children (49%) found to have none or minor importance (category 0 and 1), whereas the pain domain was important to almost all children (category 2 to 10 frequencies: 4.3%–17.2%). The frequencies of the highest ratings (category 9 and 10) were similar for all four items (range: 7.0%–9.4%). Finally, the number of missing items were approximately 7% for all four questions.
Figure 2.
Distribution of responses and missing scores of the four questions about ‘What matters most to the children’. The question asked was: ‘The worst thing about having pain in my neck, middle back or lower back is…’. The response scale of the four questions was an 11-box numeric rating scale ranging from ‘It doesn’t matter at all’ to ‘It matters a lot’ (X-axis). Total number of answered questionnaires=275.
Partial interitem correlation
High partial interitem correlations (>0.3) were identified between eight pairs of items (table 3). Each pair was closely scrutinised and discussed in terms of importance to preserve content validity and item redundancy. For example, items #13 (I become quiet) and #14 (I feel more lonely) elucidate two different severity levels of withdrawal and were therefore kept separate, even though there is a distinct connection. The process resulted in removal of items #15 (more likely to fall out with others) and #22 (I get so tired) as they were considered included in or the result of items #18 (get grumpy and annoyed) and #24 (I have less energy), respectively. This left 26 items for the factor analyses.
Table 3.
Item pairs with high partial interitem correlation (>0.3)
| Item pairs | Content | Decision |
| #7 and #8 | Hard to walk; hard to run | Both kept* |
| #9 and #10 | Hard to do sports; hard to play | Both kept |
| #13 and #14 | I become quiet; I feel more lonely | Both kept |
| #15 and #18 | More likely to fall out with others; get grumpy and annoyed | #15 removed as it may be a result of #18 |
| #16 and #17 | Worried about the pain; pain can make me scared | Both kept |
| #17 and #19 | Pain can make me scared; sad or upset more easily | Both kept |
| #22 and #24 | I get so tired; I have less energy | #22 removed as it may be a result of #24 |
| #26 and #27 | Hard to talk to mum or dad about it; hard to talk to friends about it | Both kept |
*Both kept, both items were kept to conserve content validity.
Exploratory factor analyses
Bartlett’s test (p<0.001) and KMO (=0.87) showed that the sample was factorable.34 The number of factors to retain was between 2 and 3 depending on the estimation method (screeplot=3 factors (see figure 3), parallel analysis=2 factors and Velicier’s MAP=2 factors). Consequently, we analysed both 2-factor and 3-factor models.
Figure 3.
Screeplot of the 28 questions about consequences of spinal pain. The horizontal line corresponds to a cut-off eigenvalue=1. The number of factors was arbitrarily cut at 14 to avoid cluttering of the graph.
The results of the explorative factor analysis are shown in online supplemental table 3, and the full correlation matrix of all 28 candidate items is found in online supplemental file 1.
bmjopen-2022-064382supp003.pdf (101KB, pdf)
bmjopen-2022-064382supp001.pdf (68.1KB, pdf)
3-factor models
The initial 3-factor model showed cross-loadings between two factors on 11 out of 26 items, and no loadings on any factor for item #25 (ease the pain). In the second 3-factor model, item #25 was removed resulting in four cross-loadings and only one loading for factor three (#3, hard to lift), indicating that a 3-factor structure was a poor solution.
2-factor models
The initial 2-factor model also showed no loadings for item #25 (ease the pain) on neither factor and was therefore removed. Conducting the analysis again on the remaining 25 items showed three cross-loadings for items #18 (get grumpy or annoyed), #20 (hard to concentrate) and #23 (don’t sleep so well). As item #23 did not fit with well with the other items in factor one, which primarily represented activities related to being physically active, it was removed from this factor but kept as a ‘single item’ dimension due to content validity considerations.
The third 2-factor model was conducted with the remaining 24 items. Close scrutiny of the model revealed that item #13 (I become quiet) seemed misplaced in factor 1 (activities related to being physically active). Combined with the results of the partial interitem correlation analysis, where item #13 (I become quiet) correlated with item #14 (I feel more lonely), it was decided to discard item #13, leaving 23 items in the final 2-factor EFA.
The final 2-factor EFA showed acceptable factor loadings despite three cross-loadings on items #1 (take care of myself), #18 (grumpy or annoyed) and #20 (concentrate). Based on the content of the items, it was decided that item #1 belonged in factor 1 and items #18 and #20 belonged to factor 2. A consensus process among the author group resulted in factor 1 being named ‘Physical activity component’ (13 items) and factor 2 ‘Psychosocial component’ (10 items). The final YDQ-spine structure is shown in the last column of online supplemental table 3.
Reliability
Internal consistency was explored with Cronbach’s alpha for the different factor models and ranged between 0.82 and 0.90 (online supplemental table 3). The final two-factor model showed an alpha of 0.90 for factor 1 (the ‘Physical activity component’) and 0.84 for factor 2 (the ‘Psychosocial component’).
ICF mapping of the final YDQ-spine
All items of the final 2-factor model of the YDQ-spine were mapped according to the ICF (table 4). The physical activity component (factor 1) is represented by seven mobility items, four recreation and leisure items, one self-care item and one personal factor item (energy). The psychosocial component (factor 2) is characterised mainly by personal factors (eight items) and communication (two items). Finally, the mental function construct is represented by the single sleep item.
Table 4.
ICF mapping of the final 24-items of the YDQ-spine
| Item # | Item content | ICF construct | ICF category |
| Factor 1 (physical activity component) | |||
| 1 | Take care of myself | Self-care | d540 Dressing; d530 Toileting and more |
| 2 | Head bend forward | Mobility | d415 Maintaining body position |
| 3 | Lift | Mobility | d430 Lifting and carrying objects |
| 4 | Bend forward | Mobility | d410 Changing basic body position |
| 5 | Stand | Mobility | d410 Changing basic body position |
| 6 | Sit | Mobility | d410 Changing basic body position |
| 7 | Walk | Mobility | d450 Walking |
| 8 | Run | Mobility | d455 Moving around |
| 9 | Sports | Community, social and civic life | d920 Recreating and leisure |
| 10 | Playing | Community, social and civic life | d920 Recreating and leisure |
| 11 | Ride a bike | Community, social and civic life | d920 Recreating and leisure |
| 12 | Not as much fun | Personal factor | – |
| 24 | Energy | Personal factor | – |
| Factor 2 (psychosocial component) | |||
| 14 | Lonely | Personal factor | – |
| 16 | Worried | Personal factor | – |
| 17 | Scared | Personal factor | – |
| 18 | Grumpy or annoyed | Personal factor | – |
| 19 | Sad or upset | Personal factor | – |
| 20 | Concentrate | Personal factor | – |
| 21 | School | Major life areas | d820 School education |
| 26 | Talk to mum and dad | Personal factor | – |
| 27 | Talk to friends | Personal factor | – |
| 28 | Treatment | Environmental factor | – |
| Single item | |||
| 23 | Sleep | Mental functions | b134 Sleep functions |
ICF, International Classification of Functioning; YDQ, Young Disability Questionnaire.
Scoring
The 24-items of the YDQ-spine forms two aggregate scores, one for the physical activity component and one for the psychosocial component. The sleep item forms a single score, and the optional section on what matters most are used to identify the main areas that affects the child. The YDQ-spine including a detailed user manual (see online supplemental file 2) are available online (https://www.spoergeskemaer.dk/ydq).
bmjopen-2022-064382supp002.pdf (495KB, pdf)
Discussion
This study finalises the development of a standardised questionnaire (YDQ-spine) filling a gap in the research area of measuring the consequences of spinal pain in children aged 9–12 years.15 16 The YDQ-spine consists of 24 questions measuring a physical and psychosocial component including an item on sleep disturbances due to spinal pain. In addition, it has four optional questions quantifying the impact of ‘The presence of pain’, ‘Limitations in physical activities’, ‘Limitations in social relations’ and ‘The effect on mood and concentration’ which can be used by the clinician to identify the most important area(s) affecting the individual child and thus the most relevant target for intervention.
Prior studies have shown that children are affected by spinal pain at an early age,3 4 28 46 47 and our study confirms this. Several attempts to develop questionnaires measuring the consequences of pain in children have been made,24 48–51 however, none of these cover all physical and psychosocial aspects specifically relevant to children with spinal pain.15 16 The physical component of the YDQ-spine covers mainly activity and participation (items #1–11) but also includes two personal factors (item 12: When I have pain, I don’t have as much fun as usual; item 24 : When I have pain, I have less energy). The latter two items were categorised in the physical component, as having less fun and energy refer to the child being unable to participate in the same activities as their friends,15 and this was also confirmed in the final factor analysis. The psychosocial component on the other hand, incorporates eight items representing personal factors (items #14, 16–20 and 26–27), in addition to one item describing activity and participation (item #21: When I have pain, I stay home from school) and another as an environmental factor (item #28: When I have pain, I get treatment (eg, at the general practitioner (GP), chiropractor or physiotherapist)). Staying home from school was previously found to be a passive coping strategy allowing the child to stay at home to rest indicating a certain movement anxiety,15 and it was therefore logical to assign it to the psychosocial component. Similarly, the item on receiving treatment was used as a strategy to reduce pain and pain anxiety15 and therefore fitted well in the psychosocial component.
The EFAs showed that the sleep item (item #23) could belong to both factors and therefore potentially could have an impact on both the physical and psychosocial components. Similar findings have been reported in a previous study of the factor structure of the ‘Neck disability Index’ in an adult-population, where it was argued that the sleep item could belong to several domains.52 As impaired sleep has been shown to negatively impact children15 and adults with spinal pain,53 we chose to keep the sleep item in the questionnaire as a standalone item with a separate score.
The YDQ-spine includes an optional section on What matters most to you when you have spinal pain? This section has four questions pertaining to ‘…the presence of pain’, ‘…limitations in physical activities’, ‘…limitations in social relations’ and ‘…the effect on mood and social relations’.15 The purpose of preserving these items was to assist the clinician (or researcher) to identify the main area(s) that affects the child, thereby enabling a stratified intervention strategy targeting the area(s) of most importance to the individual child.
Strengths and limitations
The study has several strengths. The study design allowed the children to report pain at more than one site when completing the questionnaire as it was combined with sections 1–3 of the Young Spine Questionnaire.24 Therefore, the YDQ-spine was developed on a broad population of children with both single and multiple pain sites which is more representative of spinal pain in children as multiple pain sites are common.54 Furthermore, the questionnaire was distributed via the teachers at the schools and was filled out independently during school hours. Therefore, children were not influenced by the parents’ opinions on the consequences of their back or neck pain.
However, the study was also limited by several factors. First, due to the requirement of anonymity of the questionnaire from the General Data Protection Regulation, we were unable to ask for gender in the questionnaire. Therefore, it was not possible to report any gender differences in disability although differences in the prevalence and frequency of back or neck pain have been found previously.8 55 We recommend that differential item functioning of the YDQ-spine is explored with regard to possible gender differences in the future.56 Second, the inclusion of children was not evenly distributed among the five Danish regions (the Region of Northern Jutland only included two children). This could in theory hamper the generalisability of our results, however, as the remaining four regions were well represented, we consider the effect of this limitation to be small. Third, we observed a skewed distribution of grade among the participants with fewest third grade children being included (15.7%). Third grade children are the poorest readers in our population, and the cumbersome process of administering and assisting these children through a long questionnaire may have discouraged the teachers to participate. Indeed, our data showed that 35% of third grade children had missing answers compared with only 18% of the sixth-grade children supporting the hypothesis that third grade children require more support filling out the YDQ-spine. We therefore encourage proper instructions and extra time allowance for the youngest children when filling out the YDQ-spine as this can increase the response rate and decrease the number of missing answers.
Conclusion
We have developed a novel questionnaire (the YDQ-spine) measuring the consequences of spinal pain in children aged 9–12 years. The questionnaire has satisfactory content validity, and EFA resulted in a 24-item measure, comprising two internally consistent domains (a physical and a psychosocial component) in addition to sleep disturbances. Furthermore, it offers an optional section on what matters most to the child allowing targeted care in clinical practice. The YDQ-spine should be psychometrically tested for reliability, validity, responsiveness and interpretation in the future.
Supplementary Material
Acknowledgments
The authors would like to thank the headmaster and school teachers from the participating schools for making data collection possible and the pupils for participating in the interviews.
Footnotes
Twitter: @hhlauridsen
Contributors: HHL is responsible for the overall content of the manuscript. HHL and LH conceived the study. All authors participated in the design and coordination. EM and GKH conducted the data collection. HHL, EM and GKH carried out the statistical analyses and all authors participated in reporting of the results and the discussion. HHL drafted the first manuscript and all authors read and approved the final manuscript.
Funding: The work was supported by the Faculty of Health of the University of Southern Denmark (grant number: N/A). The faculty had no influence on the design, strategies or conduct of this investigation.
Competing interests: None declared.
Patient and public involvement: Patients and/or the public were not involved in the design, or conduct, or reporting or dissemination plans of this research.
Provenance and peer review: Not commissioned; externally peer reviewed.
Supplemental material: This content has been supplied by the author(s). It has not been vetted by BMJ Publishing Group Limited (BMJ) and may not have been peer-reviewed. Any opinions or recommendations discussed are solely those of the author(s) and are not endorsed by BMJ. BMJ disclaims all liability and responsibility arising from any reliance placed on the content. Where the content includes any translated material, BMJ does not warrant the accuracy and reliability of the translations (including but not limited to local regulations, clinical guidelines, terminology, drug names and drug dosages), and is not responsible for any error and/or omissions arising from translation and adaptation or otherwise.
Data availability statement
Data are available upon reasonable request.
Ethics statements
Patient consent for publication
Not required.
Ethics approval
The data collection in the study was fully anonymised and this study was approved by the Danish Data Protection Agency (Nr. 10.075), and the Scientific Ethics Committee of Southern Denmark was notified and concluded that the project did not require approval according to Danish regulations (J.Nr. 20182000-114).
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Associated Data
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Supplementary Materials
bmjopen-2022-064382supp003.pdf (101KB, pdf)
bmjopen-2022-064382supp001.pdf (68.1KB, pdf)
bmjopen-2022-064382supp002.pdf (495KB, pdf)
Data Availability Statement
Data are available upon reasonable request.