This study outlines the extent of healthcare utilization across different healthcare settings by children and youth with MSD in the population of Ontario, Canada. The most notable findings are the high proportion of children and youth who saw physicians with MSD in ambulatory care settings, and the importance of primary care physicians in assessing and triaging these patients. Our overall estimate that 1 in 8 children made physician visits each year for MSD is considerably higher than previous estimates. However, previous studies tend to base their estimates on a limited age range of patients with MSD, mainly adolescents
[
9,
10], data from only one sector of the healthcare system, such as primary care
[
11], or a restricted range of diagnostic terms
[
11,
12]. To our knowledge, this is the first study to describe the prevalence of healthcare utilization over the full age range of the paediatric population using an inclusive definition of musculoskeletal disorders and all types of physicians for a large and representative population. Our findings suggest that the prevalence of MSD in children may have been previously underestimated.
Integrating the findings from this study with an estimate for the same year that a total of 2.8 million people of all ages made physician visits for MSD
[
6] suggests that 13.5% of all individuals with visits to physicians for MSD were children and youth. This is a substantial proportion if one considers that generally MSD increases with age. Furthermore, if we juxtapose our findings with an estimate that 86% of children make at least one doctor visit for any condition per year in Ontario
[
8], it is possible of children visiting doctors for any condition that as many as 1 in 10 do so for MSD. Given this relatively high proportion it is perhaps surprising that these conditions have not received much attention in the paediatric or other medical literature.
Injury and related conditions were the most frequent reasons for contact with the healthcare system in this study. De Inocencio et. al.
[
13] similarly reported that injury was the most common cause of musculoskeletal pain causing children between 3 and 15

years old to present to a primary care paediatrician in an ambulatory setting in Spain. Our study found injury increases in frequency with age and was more prevalent in boys than girls, which mirrors findings from other studies
[
14-
16]. While the underlying cause of injury is unknown, the high proportion of children with injury underscores the need to advise children and parents about safety and injury prevention. Although a minority, the number requiring surgery is of concern because this is a risk factor for longer term disability or other sequelae such as later osteoarthritis
[
17,
18].
Overall, we found that 2.8% of children saw a physician for some kind of arthritis each year, mostly soft tissue disorders and unspecified arthritis. The nature of these conditions is unknown. The estimate of 3.5 per 1,000 children presenting with inflammatory or other arthritis is of similar order of magnitude to a US estimate
[
12], and our estimate for inflammatory arthritis in children of 1.4 per 1,000 is in the middle of the range of the diverse estimates in the literature
[
19].
While children with arthritis and related conditions were mainly seen by primary care physicians, most of children with inflammatory arthritis were seen by paediatricians. Paediatricians also saw about a quarter of children with unspecified arthritis, pointing perhaps to their more general consultative role. The relatively small proportion of children and youth with visits to rheumatologists may be an artefact of coding whereby some paediatric rheumatologists might have been coded as paediatricians in the billing database, or this could reflect existing barriers to access to paediatric rheumatologists
[
20]. The adult literature concerning inflammatory arthritis shows that patients who see specialists, as opposed to those who see primary care physicians, are more likely to be prescribed appropriate disease modifying anti-rheumatic drugs
[
21,
22]. It would be interesting to know if there were treatment differences for children and youth who see different types of physicians. Visits to orthopaedic surgeons, representing 24 per 1,000 children each year, were, as expected, most frequently for injury, particularly fractures and dislocations and joint derangement.
While the majority of contacts with the healthcare system were in ambulatory settings a significant minority of children, 3%, were seen in the emergency department. Data on geographic variations in the availability of physician services in Ontario suggest that there are more emergency room visits in areas of lower physician availability, which tend to be rural and remote communities
[
7]. It has also been shown that children living in remote areas are likely to have longer referral times to paediatric rheumatology services
[
23], suggesting potential deficiencies in care for children with MSD who live in these areas.
Our study highlights the large volume of physician visits that children and youth make to primary care physicians, paediatric and other consultant specialists for MSD. There has been concern expressed about the inadequacy of training and confidence of physicians and medical students in diagnosing and managing MSD
[
24-
26], which is not confined to adult medicine
[
27]. Studies in the northern regions of the UK and California in the US showed no or minimal exposure to paediatric MSD during training
[
27,
28], and that most trainees, practicing primary care physicians and paediatricians had no or little confidence with the paediatric MSD assessment, especially in comparison with other organ systems
[
28]. In view of the relatively large proportion of children with MSD complaints who present to physicians, particularly primary care physicians and paediatricians, this study reinforces the need for training programs to devote an appropriate amount of time teaching residents and students about paediatric MSD conditions including how to carry out an age appropriate joint examination and to make timely referrals if warranted to a relevant specialist
[
23,
29].
A strength of this study is that it captures all visits to physicians by children in the most populated province in Canada, as well as all emergency department visits, outpatient surgeries and inpatient hospital admissions. It shares the limitations of other studies based on administrative databases. The ambulatory care billing database uses a limited range of diagnostic codes, and the accuracy of our findings relies on the accuracy of the coding by the billing-physician. Also, as only one diagnosis can be billed for each consult, visits for MSD may be underestimated if children present with multiple conditions where MSD is not coded. Similarly, inpatient admissions may be underestimated if comorbid conditions were coded as the reason for admission. The billing data may also miss salaried physicians, although most are required to shadow-bill to OHIP, which means they would be counted in our study. There may also be inaccuracies in the recorded physician specialty, particularly between paediatricians and paediatric rheumatologists. Data on patient characteristics are also limited to age and gender with no information on other relevant aspects such as socioeconomic status or body mass index.