Development of the Young Spine Questionnaire
Development of the Young Spine Questionnaire
The Young Spine Questionnaire is a much needed novel questionnaire measuring childhood and early adolescent spinal pain prevalence rates in addition to pain intensity, activity restrictions, care seeking behaviour and the possible influence of parental back trouble in a standardised fashion. Our preliminary results suggest that the YSQ is feasible, have valid spinal pain prevalence estimates and pain scores and is phrased in such a manner that the target population has an acceptable level of item understanding.
The drawings of the spinal areas included in the YSQ were adapted from the Standardised Nordic Questionnaires which originally were developed for the adult population. Our results demonstrate that children at the age of 10 have a different understanding of the boundaries of especially the thoracic and lumbar spine compared to adults. Many found it difficult to localise the transition from the thoracic to the lumbar spine which might be due to immaturity of the children's anatomical knowledge. Also, most adults have an understanding of the concept "low back pain" which most of the children in this age group have not yet developed. Changing the drawings to include more bony landmarks helped to avoid these problems.
The original drawings also included the buttocks and thus the coccyx. Therefore, the frequent falls (e.g. from play and sports) on the buttocks causing coccygeal pain and/or bruised buttocks would be classified as low back pain. In the original drawing, the buttocks are included to capture pain radiating from the lumbar spine to the buttocks, but due to a high rate of non-spinal buttock/coccyx pain in this age group, it was a necessary trade-off to exclude the buttocks from the drawing.
In all the test phases, the sequence of sections was the same (cervical, thoracic, lumbar). Since only very few of the children had problems identifying the neck area, this may have been used as a reference point improving the identification of the other areas. It is not known, how the drawings of the thoracic and lumbar areas will be perceived if they are shown in another sequence or used individually.
The YSQ contain a frequency question (which can be dichotomised to represent lifetime prevalence) as well as point and 1-week prevalence estimates for all the spinal regions. Pilot test I revealed prevalence estimates of 41.5% and 18.8% (lifetime and 1-week) for the cervical spine, 28.3% and 3.8% for the thoracic spine and 47.2% and 11.3% for the lumbar spine. These estimates agreed well with findings from the interviews which ranged between 85.7–97.9% and we therefore believe that the prevalence questions accurately reflect the children's perception of pain prevalence. In addition, our estimates were similar to reported lifetime and 1-week estimates in the same age group which ranged from 18.8–51.0% and 23–44.3% in the cervical spine, 9.5–72% and 3.4–51.4% in the thoracic spine, and 7.0–72.0% and 9.5–20.0% in the lumbar spine. To our knowledge no point estimates have been reported in the literature for comparison. On the basis of this, we believe that by asking for specific answer categories and subsequently collapse them for analyses, a more precise estimate can be obtained compared to simply asking "Have you ever had pain?". However, because the prevalence estimates are based on the first version of the questionnaire and due to the small sample sizes these estimates should be interpreted with caution.
When developing the YSQ we decided not to include a focused lifetime prevalence estimate question due to the risk of "memory decay" where children are more likely to forget 'episodes' of spinal problems with the passage of time. Secondly, "forward telescoping of events", a tendency to recollect episodes of e.g. spinal problems as having happened more recently, are more likely to bias estimates with long recall periods. Instead we included a frequency of spinal problems question which does not focus on a set time-frame. If needed for comparison to other studies, this can be converted into lifetime prevalence by collapsing the three last answer categories. However, we believe there should be more focus on frequency and duration, as a single short period of back pain is less likely to have long term consequences than more long-lasting or recurrent back trouble.
For each of the three spinal regions we added the rFPS as measure of pain intensity. To our knowledge the rFPS has not been used in spinal pain studies of children or adolescents, and it is therefore unclear how well the pain scale performs for this condition. However, our results showed acceptable correlation between the rFPS and the NRS (r = [0.67–0.79]) supporting the validity of the rFPS also for spinal pain. Similar results were found in a study of post-operative pain ratings comparing the same scales (r = 0.89).
In the Danish translation of the rFPS we used "rigtig meget ondt" (very much pain) rather than the commonly used adult version "værst tænkelige smerte" (worst pain imaginable) as the latter is considered difficult for children to understand since they have a limited experience of pain intensity.
Section 4 of the questionnaire contains questions related to activity restrictions (physical activity and school absenteeism) and care seeking behaviour (treatment received). We included these questions as proxy measures for severity of pain, and in combination with the rFPS they may have the potential to distinguish trivial from significant pain. Our experience from the pilot-tests is that children's reporting of pain is more spontaneous and immediate compared to adults resulting in a higher frequency of trivial pain being recorded when answering the prevalence questions. This supported our decision to include these measures, so it is possible to some degree to qualify the answers in order to target primary intervention programmes to children with high risk of developing spinal pain in their adult life.
The last section measures the child's perception and consequences of the parents back trouble. These questions had to be completely rephrased to be very specific, illustrating the need for testing questions in the target population. We believe children to a certain extent will imitate their parents' behaviour reinforcing the relevance of the information when interpreting the children's answers to the participation questions in section 4.
After the completion of final version of the YSQ it was decided to include section 4 and 5 as optional since they may not be relevant in studies which primarily focus on prevalence.
The study has several strengths. Firstly, the questionnaire includes all 3 spinal areas and considers each as a distinct region. Secondly, the emphasis on relevant content and content understanding of the target population during the development phase resulted in high content validity of the questionnaire. This was achieved using an iterative process combining ordinary questionnaire data with interview data.
Several drawbacks need to be mentioned. First of all, the questionnaire needs to be tested for reliability. Secondly, the questionnaire has only been tested on school-children in the age range of 9–11 years and cannot be generalised to other age groups. Thirdly, the iterative process and testing of the YSQ was mainly performed on preliminary versions (YSQ-1 to YSQ-3). It resulted in changes to all included items (either the question or the answer categories) and drawings for which reason caution is advised when applying these results to the final version. We recommend that future validation studies include a thorough evaluation of the items in the final version of the YSQ. Finally, we reinforce that the questionnaire has been developed and tested for use in cross-sectional cohort studies. At this point in time it is not recommended to use it in a longitudinal setting measuring change for several reasons: 1) the questions and response options have not been designed for the purpose of being responsive to change, and 2) the questionnaire does not have a summary score and change scores are therefore reliant on the validity of scores on single questions. Future studies need to ascertain whether or not the included questions can be used in a longitudinal design, measuring change.
Discussion
The Young Spine Questionnaire is a much needed novel questionnaire measuring childhood and early adolescent spinal pain prevalence rates in addition to pain intensity, activity restrictions, care seeking behaviour and the possible influence of parental back trouble in a standardised fashion. Our preliminary results suggest that the YSQ is feasible, have valid spinal pain prevalence estimates and pain scores and is phrased in such a manner that the target population has an acceptable level of item understanding.
Drawings
The drawings of the spinal areas included in the YSQ were adapted from the Standardised Nordic Questionnaires which originally were developed for the adult population. Our results demonstrate that children at the age of 10 have a different understanding of the boundaries of especially the thoracic and lumbar spine compared to adults. Many found it difficult to localise the transition from the thoracic to the lumbar spine which might be due to immaturity of the children's anatomical knowledge. Also, most adults have an understanding of the concept "low back pain" which most of the children in this age group have not yet developed. Changing the drawings to include more bony landmarks helped to avoid these problems.
The original drawings also included the buttocks and thus the coccyx. Therefore, the frequent falls (e.g. from play and sports) on the buttocks causing coccygeal pain and/or bruised buttocks would be classified as low back pain. In the original drawing, the buttocks are included to capture pain radiating from the lumbar spine to the buttocks, but due to a high rate of non-spinal buttock/coccyx pain in this age group, it was a necessary trade-off to exclude the buttocks from the drawing.
In all the test phases, the sequence of sections was the same (cervical, thoracic, lumbar). Since only very few of the children had problems identifying the neck area, this may have been used as a reference point improving the identification of the other areas. It is not known, how the drawings of the thoracic and lumbar areas will be perceived if they are shown in another sequence or used individually.
Prevalence Estimates
The YSQ contain a frequency question (which can be dichotomised to represent lifetime prevalence) as well as point and 1-week prevalence estimates for all the spinal regions. Pilot test I revealed prevalence estimates of 41.5% and 18.8% (lifetime and 1-week) for the cervical spine, 28.3% and 3.8% for the thoracic spine and 47.2% and 11.3% for the lumbar spine. These estimates agreed well with findings from the interviews which ranged between 85.7–97.9% and we therefore believe that the prevalence questions accurately reflect the children's perception of pain prevalence. In addition, our estimates were similar to reported lifetime and 1-week estimates in the same age group which ranged from 18.8–51.0% and 23–44.3% in the cervical spine, 9.5–72% and 3.4–51.4% in the thoracic spine, and 7.0–72.0% and 9.5–20.0% in the lumbar spine. To our knowledge no point estimates have been reported in the literature for comparison. On the basis of this, we believe that by asking for specific answer categories and subsequently collapse them for analyses, a more precise estimate can be obtained compared to simply asking "Have you ever had pain?". However, because the prevalence estimates are based on the first version of the questionnaire and due to the small sample sizes these estimates should be interpreted with caution.
When developing the YSQ we decided not to include a focused lifetime prevalence estimate question due to the risk of "memory decay" where children are more likely to forget 'episodes' of spinal problems with the passage of time. Secondly, "forward telescoping of events", a tendency to recollect episodes of e.g. spinal problems as having happened more recently, are more likely to bias estimates with long recall periods. Instead we included a frequency of spinal problems question which does not focus on a set time-frame. If needed for comparison to other studies, this can be converted into lifetime prevalence by collapsing the three last answer categories. However, we believe there should be more focus on frequency and duration, as a single short period of back pain is less likely to have long term consequences than more long-lasting or recurrent back trouble.
Pain Ratings
For each of the three spinal regions we added the rFPS as measure of pain intensity. To our knowledge the rFPS has not been used in spinal pain studies of children or adolescents, and it is therefore unclear how well the pain scale performs for this condition. However, our results showed acceptable correlation between the rFPS and the NRS (r = [0.67–0.79]) supporting the validity of the rFPS also for spinal pain. Similar results were found in a study of post-operative pain ratings comparing the same scales (r = 0.89).
In the Danish translation of the rFPS we used "rigtig meget ondt" (very much pain) rather than the commonly used adult version "værst tænkelige smerte" (worst pain imaginable) as the latter is considered difficult for children to understand since they have a limited experience of pain intensity.
School, Leisure, Treatment and Family
Section 4 of the questionnaire contains questions related to activity restrictions (physical activity and school absenteeism) and care seeking behaviour (treatment received). We included these questions as proxy measures for severity of pain, and in combination with the rFPS they may have the potential to distinguish trivial from significant pain. Our experience from the pilot-tests is that children's reporting of pain is more spontaneous and immediate compared to adults resulting in a higher frequency of trivial pain being recorded when answering the prevalence questions. This supported our decision to include these measures, so it is possible to some degree to qualify the answers in order to target primary intervention programmes to children with high risk of developing spinal pain in their adult life.
The last section measures the child's perception and consequences of the parents back trouble. These questions had to be completely rephrased to be very specific, illustrating the need for testing questions in the target population. We believe children to a certain extent will imitate their parents' behaviour reinforcing the relevance of the information when interpreting the children's answers to the participation questions in section 4.
After the completion of final version of the YSQ it was decided to include section 4 and 5 as optional since they may not be relevant in studies which primarily focus on prevalence.
Strength and Limitations
The study has several strengths. Firstly, the questionnaire includes all 3 spinal areas and considers each as a distinct region. Secondly, the emphasis on relevant content and content understanding of the target population during the development phase resulted in high content validity of the questionnaire. This was achieved using an iterative process combining ordinary questionnaire data with interview data.
Several drawbacks need to be mentioned. First of all, the questionnaire needs to be tested for reliability. Secondly, the questionnaire has only been tested on school-children in the age range of 9–11 years and cannot be generalised to other age groups. Thirdly, the iterative process and testing of the YSQ was mainly performed on preliminary versions (YSQ-1 to YSQ-3). It resulted in changes to all included items (either the question or the answer categories) and drawings for which reason caution is advised when applying these results to the final version. We recommend that future validation studies include a thorough evaluation of the items in the final version of the YSQ. Finally, we reinforce that the questionnaire has been developed and tested for use in cross-sectional cohort studies. At this point in time it is not recommended to use it in a longitudinal setting measuring change for several reasons: 1) the questions and response options have not been designed for the purpose of being responsive to change, and 2) the questionnaire does not have a summary score and change scores are therefore reliant on the validity of scores on single questions. Future studies need to ascertain whether or not the included questions can be used in a longitudinal design, measuring change.
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