This study is the first comprehensive overview of IRs for spine-related diagnoses in Danish children and adolescents over a 13-year period. Children are rarely diagnosed with spine-related conditions in hospital departments, with an approximately average 63/100,000 incident cases per annual quarter, though IRs fluctuated between 50 and 90 per 100,000 children over the study period. When diagnoses are provided, they are often related to whiplash, which was the most common diagnostic group until 2018, after which it declined. This decline aligns with observations from Australia, where a similar decline in whiplash diagnoses was seen in motor vehicle accident insurance data around the same period [22]. Possible explanations include decreased clinical awareness, changes in diagnostic or reporting practices, or shifts in healthcare policies regarding whiplash-related conditions. Likewise, structural diagnoses were very common but also declined after 2015. This pattern may reflect a range of factors, including an actual decrease in such cases, a shift in diagnostic coding preferences, or changes in referral and access to hospital care. Without further data, the exact drivers of this trend remain uncertain. On the contrary, regional diagnoses (e.g., non-specific spinal pain) increased quite substantially during the study period, stabilizing at ~30/100,000 after 2019. The increased use of non-specific diagnostic codes aligns with the broader recognition of the multifactorial nature of spinal pain. This development may reflect a gradual shift toward a biopsychosocial understanding of spinal pain in clinical practice, where biomedical explanations are supplemented by attention to psychological and social dimensions. While our data do not allow us to examine clinical reasoning directly, the coding trend may signal increased acceptance of non-specific pain presentations as legitimate diagnoses. Such a shift is in line with current international guidelines and may influence how children and families experience clinical encounters and expectations of care [23, 24]. Although we are not aware of any specific national policy or guideline changes in Denmark to confirm such a shift in clinical orientation, the recent update of the WHO’s ICD-11 reflects an international movement toward a biopsychosocial approach to pain classification. ICD-11 introduces the category of chronic primary pain, recognizing pain as a disease entity rather than merely a symptom. This framework emphasizes the role of psychological and social dimensions in pain experiences, which may influence clinical documentation practices even in settings where ICD-11 has not yet been adopted.

Additionally, the emergence of emergency department diagnosis from 2019 and onwards highlights potential shifts in healthcare access that should be explored further.

The non-specificity and the impact of social and psychological factors have received much attention in spinal pain over recent years in national and international guidelines [25] and large media coverage in relation to the publication of the Lancet Low Back Pain series [26,27,28]. While these trends primarily concern adults, it is possible that as children grow older, their diagnostic patterns begin to resemble those seen in adults. This could be a potential reason for the apparent shift toward more non-specific codes. However, given the study design, we cannot define it as shifts in clinical practice rather than administrative priorities or other factors.

Future studies should focus on investigating whether the diagnostic coding practices used in Danish hospital departments have any consequences for children. In adults with low back pain, the “label” which is associated with the diagnostic codes does appear to impact people, and sometimes negatively [29]. It would be valuable to investigate how children diagnosed with spine-related conditions move through the healthcare system, from primary to secondary care, and back. Comparing healthcare trajectories between children with and without spine-related diagnoses could provide insights into differences in management and treatment. Still, variability in diagnostic practices may lead to different expectations or outcomes for children, highlighting the broader need for standardizing coding protocols [30]. While the rise in non-specific diagnoses has been linked [30, 31] to referral patterns in adults, its implications for children remain uncertain.

By excluding children with spinal pain diagnoses from 2007 and 2008, we minimized selection bias and aimed for the inclusion of true incident cases. However, some children may still have had earlier spine-related diagnoses. The classification of diagnostic groups was designed to be clinically relevant but may not comprehensively represent all spine-related conditions. Moreover, some B-diagnoses may represent transient symptoms that do not require further examination or follow-up, leading to overrepresentation in our findings.

The choice and specificity of diagnostic coding may influence how clinicians approach treatment planning and referrals, particularly when coding guides reimbursement, triage urgency, or access to specialist services. Non-specific diagnoses, while clinically valid, may also shape family expectations, follow-up patterns, and resource utilization [32]. Clarifying and standardizing coding practices could therefore have important implications for clinical decision-making and equity in care delivery.

The observed regional differences in incidence rates may reflect variations in clinical culture, resource availability, or coding practices across hospital regions. These disparities raise questions about consistency in care and equity in access. Addressing such variation through national coding standards or harmonized clinical pathways may help reduce unwarranted differences in diagnostic activity and ensure more uniform service delivery.

This study was motivated by a lack of knowledge about how spine-related diagnoses are distributed and coded in hospital settings for children. Our findings suggest that diagnostic practices have changed over time and that regional differences persist—even within a small, high-income country with universal healthcare access and coordinated pediatric care pathways. These insights may inform clinical training, resource allocation, and the development of standardized diagnostic frameworks. Given the degree of variation observed in Denmark, similar or greater inconsistencies may exist in other countries with more fragmented health systems. Future research could explore the impact of diagnostic labeling on health outcomes, the patient journey across primary and secondary care, and the potential implications of non-specific coding for treatment decisions and parental perceptions.