Screening for scoliosis - New recommendations, old dilemmas, no straight solutions

Table 1 Major current and historical recommendations about screening for scoliosis

Institution, yr	Recommendation	Standard of development	Characteristics
Current recommendations:
United States Preventive Services Task Force, 2018[34]	No recommendation1 suggestion for practice: “(…) If the service is offered, patients should understand the uncertainty about the balance of benefits and harms”	Systematically developed; Screening programme criteria-based	Methods and standards following the USPSTF Procedure Manual; Systematic review addressing six key questions2; Previous recommendation (2004): Against screening
AAP Bright Futures Guidelines, 2017/ 2019[36]	Recommended (examination of the back)	Endorsement of the SRS/AAOS/ POSNA/AAP 2015 position (below)	Examinations for scoliosis and “other abnormalities” during all (11-21 yr) Adolescence Health Supervision Visits
SOSORT, 2016 (published 2018)[35]	Recommended (school screening programmes)	Consensus-based	Delphi method; Panel of experts and scoliosis conservative treatment practitioners; 2007 SOSORT screening consensus paper[45] recommended as “a reference for specific insights”
United Kingdom National Screening Committee, 2016[32]	Not recommended (national population-based screening programme)	Systematically developed; United Kingdom National Security Council (2015) screening programme criteria-based	Based on systematic evidence review[43]; Criteria addressing the condition, the test, the intervention in terms of a clinically, socially and ethically acceptable screening programme1; Recommendation sustained (2006, 2012)
SRS/AAOS/ POSNA/AAP, 2015[33,46]	Recommended (to be conducted in a medical home setting)	Opinion-based; narrative, including information on new evidence	Readers encouraged “to reach their own decisions” as the statement is not based on a systematic review; position confirmed[40] after the USPSTF 2018 recommendation
SRS International Task Force, 2013[31]	Recommended (school screening)	Consensus-based; research synthesis-guided	Expert consensus (Delphi method, seven surgeons, epidemiologist) on test technical efficacy, clinical, program, treatment, and cost effectiveness, using a dedicated systematic review[47] and other available critical literature reviews
Historical (and discontinued) recommendations:
National Health and Medical Research Council, Australia, 2002[48]	Not recommended (rescinded guideline, not updated, archived[48])	Systematically developed	Based on critical review against criteria of screening tests characteristics, treatment effectiveness, burden of suffering; No current guidelines or guidelines in development
Canadian Task Force on Preventive Health Care3, 1994[49]	No recommendation: insufficient evidence to recommend for or against (historical guideline, not updated[49])	Systematically developed	Based on critical review of the evidence of benefits and harms of screening and treatment; No current guidelines or guidelines in development

¹The current evidence is insufficient to assess the balance of benefits and harms of the service. Evidence is lacking, of poor quality, or conflicting, and the balance of benefits and harms cannot be determined”[34];

²For more details see Table 8;

³Formerly Canadian Task Force on the Periodic Health Examination. AAOS: American Academy of Orthopedic Surgeons; POSNA: Pediatric Orthopedic Society of North America, AAP: American Academy of Pediatrics; AIS: Adolescent idiopathic scoliosis; SOSORT: Scientific Society on Scoliosis Orthopaedic and Rehabilitation Treatment; SRS: Scoliosis Research Society.

Table 2 Terms related to people-centred care and person-centred care

Terms
People-centred care	“Organised around the health needs and expectations of people rather than diseases (…) requires that people have the education and support they need to make decisions and participate in their own care”[5]; “extends the concept of patient-centred care to individuals, families, communities and society”[66]
Person-centred care	“Care approaches that see the person as a whole with many levels of needs and goals, with these needs coming from their own personal and social determinants of health”[5]
Engagement	“Involving people and communities in the design, planning and delivery of health services that (…) enable them to make choices about care and treatment options”[66]
Patient decision aids	“Evidence-based tools designed to help patients specific and deliberated choices among health-care options”[72]
Shared decision-making	“Process through which clinicians and patients make health care choices together”[67]

Table 3 Generic standards of trustworthiness for guidelines and recommendations

Institute of Medicine, 2011[10]

Guidelines International Network, 2012[11]

1. Establishing transparency; 2. Management of conflicts of interest; 3. Guideline development group composition: multidisciplinary group, methodologist involvement, patient and public perspectives; 4. Clinical practice guideline – systematic review intersection/ use of systematic review evidence; 5. Evidence foundations for and rating strength of recommendations; 6. Specific and unambiguous articulation of recommendations; 7. External review; and 8. Updating

1. Composition of guideline development group; 2. Decision-making process; 3. Conflicts of interest; 4. Scope of a guideline; 5. Methods; 6. Evidence reviews; 7. Guideline recommendations; 8. Rating of evidence and recommendations; 9. Peer review and stakeholder consultations; 10. Guideline expiration and updating; and 11. Financial support and sponsoring organization”

Table 4 Screening-addressed standards of trustworthiness for guidelines and recommendations

“How to use guidelines and recommendations about screening”, Evidence-Based Medicine Working Group, 1999[28]
“Are the recommendations valid?
Is there randomized controlled trial evidence that earlier intervention works?
Were the data identified, selected and combined in an unbiased fashion?
What are the recommendations and will they help you in caring for your patients?
What are the benefits?
What are the harms?
How do these compare in different people and with different screening strategies?
What is the impact of people’s values and preferences?
What is the impact of uncertainty?
What is the cost-effectiveness?”

Table 5 Wilson and Jungner screening principles, World Health Organization 1968[29]

“Principles of early disease detection” Wilson and Jungner, WHO, 1968[29]
1 The condition sought should be an important health problem
2 The natural history of the condition, including development from latent to declared disease, should be adequately understood
3 There should be a recognizable latent or early symptomatic stage
4 There should be a suitable test or examination
5 The test should be acceptable to the population
6 There should be an agreed policy on whom to treat as patients
7 There should be an accepted treatment for patients with recognized disease
8 Facilities for diagnosis and treatment should be available
9 The cost of case-finding (including diagnosis and treatment of patients diagnosed) should be economically balanced in relation to possible expenditure on medical care as a whole
10 Case-finding should be a continuing process and not a “once and for all” project

WHO: World Health Organization.

Table 6 Fifty years after Wilson and Jungner, Consolidated principles for screening, 2018[9]

“Consolidated principles for screening” Dobrow et al[9], 20181
“Disease/condition principles:
1 Epidemiology of the disease or condition (..) should be adequately understood, and the disease or condition should be an important health problem
2 Natural history of disease or condition (…) should be adequately understood, the disease or condition is well-defined, and there should be a detectable preclinical phase
3 Target population for screening (…) should be clearly defined (e.g., with an appropriate target age range), identifiable and able to be reached
Test/ intervention principles:
4 Screening test performance characteristics (…) should be appropriate for the purpose, with all key components specific to the test (…) being accurate (…) and reliable or reproducible. The test should be acceptable to the target population and it should be possible to perform or administer it safely, affordably and efficiently
5 Interpretation of screening test results. Screening test results should be clearly interpretable and determinate (e.g., with known distribution of test values and well-defined and agreed cut-off points) to allow identification of the screening participants who should (and should not) be offered diagnostic testing and other postscreening care
6 Postscreening test options. There should be an agreed (…) course of action for screening participants with positive screening test results that involves diagnostic testing, treatment or intervention, and follow-up care that will modify the natural history and clinical pathway for the disease or condition; that is available, accessible and acceptable to those affected; and that results in improved outcomes (…). The burden of testing on all participants should be understood and acceptable, and the effect of false-positive and false-negative tests should be minimal
Program/ system principles:
7 Screening program infrastructure (…)
8 Screening program coordination and integration (…)
9 Screening program acceptability and ethics. All components of the screening program2 should be clinically, socially and ethically acceptable to screening participants, health professionals and society, and there should be effective methods for providing screening participants with informed choice, promoting their autonomy and protecting their rights
10 Screening program benefits and harms. The expected range and magnitude of benefits (…) and harms (…) for screening participants and society should be clearly defined and acceptable, and supported by existing high-quality scientific evidence (or addressed by ongoing studies) that indicates that the overall benefit of the screening program outweighs its potential harms
11 Economic evaluation of screening program (…) (e.g., cost-effectiveness analysis, cost–benefit analysis and cost–utility analysis) (…), using a health system or societal perspective, (…) to assess the full costs and effects of implementing, operating and sustaining the screening program while clearly considering the opportunity costs and effect of allocating resources to other potential nonscreening alternatives (…)
12 Screening program quality and performance management (…)

¹based on a systematic review and a modified Delphi consensus process, using 41 sets and 367 screening principles[9]; elaborations abridged;

²i.e. “recruitment, testing, information access, diagnosis, referral, treatment, follow-up, patient education and support, staff training and program management and evaluation”[9].

Table 7 “Drivers of overdiagnosis” and their relation to scoliosis screening

“Drivers of overdiagnosis”, Kale et al[77], 2018		Examples of disputable and unclear scoliosis issues
Category	Factor
Broadening disease definitions	Lowering of diagnostic thresholds	Cut-off point of 10° Cobb, treatment starts from 20°-25° Cobb[26,43]; proposed 6° Cobb cut-off point[79]
	Recognition of risk factors as pre-diseases	Mild scoliosis with no symptoms, disputable risk of progression; inconclusive/unconvincing evidence for treatment effectiveness
Technology	Use of advanced technology for diagnosis	Proposals of advanced imaging technologies[79,80]; and follow-up tests connected to potential overdiagnosis
	Use of more sensitive screening tests
Public health interventions	Widespread screening	Screening programmes mainly school-based[26,56]; millions of adolescents subjected to school screening[56,62-64]
Culture of medical care	Value of diagnosis for its own sake	Testing encouraged by professional organisations[33,35,36,46,59]
Clinician cognitive errors	Overestimation of benefit of therapy in mild or low risk disease	Evidence-to-practice gaps as regards effectiveness of early conservative treatment[25,26,42] and differences in long term health outcomes between treated and untreated people[26,43,81]
System factors	Financial incentives for more testing	-
Evidence limitations	Lack of clarity regarding disease spectrum in studies of diagnostic accuracy	Disputable AIS severity divisions (mild–moderate–severe) vs broad and unspecified curve spectrums (e.g 10°-50° Cobb) and screening test accuracy[26,43]

AIS: Adolescent idiopathic scoliosis.

Table 8 Unmet and partially met United States Preventive Services Task Force[26] and United Kingdom National Screening Committee[43] key questions and criteria, tested in recommendation formulation on screening for scoliosis

Criterion	Findings/conclusions
Key Questions, United States Preventive Services Task Force, 2018[26]:
Does screening for improve: (1) Health AIS outcomes, and (2) The degree of abnormal spinal curvature in childhood or adulthood?	No relevant RCTs or CCTs, evaluating the impact of screening on curve severity or adult health outcomes
What is the association between severity of spinal curvature in adolescence and health outcomes in adulthood?	No studies directly addressing this question: none of two included studies reported health outcomes data stratified by curve degree at skeletal maturity
What are the harms of screening for AIS?	No studies met inclusion criteria
What are the harms of treatment of AIS that has a Cobb angle of less than 50° at diagnosis?	Harms of bracing reported in one good-quality study[,81] (relatively benign skin problems and nonback pain; one out of 146 participants hospitalised due to anxiety and depression); no other studies or evidence on other harms
Screening criteria1, United Kingdom National Screening Committee, 2016[43]:
There should be a simple, safe, precise and validated screening test	Not met; Poor PPV of FBT test in distinguishing whether treatment or observation is needed; potential overdetection, waste of resources and unnecessary x-ray exposure
The distribution of test values in the target population should be known and a suitable cut-off level defined and agreed	Partially met; No single established cut-off value; other uncertainties, including additional use of Moiré topography and optimal screening age
There should be an effective treatment or intervention for patients identified through early detection, with evidence of early treatment leading to better outcomes than late treatment	Not met; Two studies were eligible, but were conducted in clinically detected cases, and did not compare treatment after screen detection and after clinical detection; no evidence found on effectiveness of conservative treatments of mild scoliosis and on surgical treatment outcomes in screen-detected vs clinically detected severe cases
There should be agreed evidence based policies covering which individuals should be offered treatment and the appropriate treatment to be offered	Partially met; Specific Cobb angle cut-off for observation or treatment introduction, or a particular treatment approach, difficult to identify
There should be evidence that the complete screening programme (test, diagnostic procedures, treatment/ intervention) is clinically, socially and ethically acceptable to health professionals and the public	Not met; Adherence to bracing prescribed following screen detection difficult to define/recognise; no studies on adherence to other conservative treatments or on uptake following recommendation for surgery

¹There are 20 United Kingdom National Screening Committee screening criteria, addressing the condition, the test, the intervention, the programme, and implementation criteria; the table includes criteria categorised as “unmet” or “partially met” in the Screening for adolescent idiopathic scoliosis: external review against programme appraisal criteria for the United Kingdom National Screening Committee[43]. AIS: Adolescent idiopathic scoliosis; RCT: Randomised controlled trial; CCT: Clinical controlled trial; FBT: Forward bend test.