Table 1. Characteristics of cohort studies in an idiopathic scoliosis population comparing bracing with observation.

Reference	Study design	Study population	Bracing	Observation	Outcomes
Nachemson and Peterson (1995)5	Prospective cohort April 1985–March 1989	N = 240 100% female Mean age: not reported (NR) Skeletal age: 10–15 y Cobb angle: 25–35°	n = 111 23 lost to follow-up (F/U) Underarm plastic brace to be worn 16 h daily Cobb angle: 25–35°	n = 129 9 lost to F/U Cobb angle: 25–35°	Failure rate defined as an increase in the curve of at least 6°
Danielsson et al. (2007) 6 Subpopulation of Nachemson	Prospective cohort April 1985–March 1989	N = 92 100% female Skeletal age: 10 –15 y Cobb angle: 25–35°	n = 35 6 lost to F/U Boston brace to be worn 16 h daily Cobb angle: 31.8° (26–38°)	n = 57 8 lost to F/U Cobb angle: 29.5° (23–39°)	Surgery rate at 16 y after maturity
Fernandez-Feliberti et al. (1995)7	Retrospective cohort 1982–1990	N = 101 74% female Mean age: NR	n = 54/69 Sex: NR 15 patients excluded due to poor compliance TLSO brace worn 23–24 h daily Cobb angle: ≤ 29%: 46.3%	n = 47 (indicated for TLSO, but never used) Sex: NR Cobb angle: ≤ 29%: 57.5%	Surgery rate Cobb angle < 40°
Cheung et al. (2007) 8	Retrospective cohort December 1990	N = 92 83% female Mean age: 17 y Age range: 11– 22 y	N = 46 87% female Mean age: 16 y Age range: 11–20 y Rigid underarm brace worn minimum of 20 h daily Cobb angle: 28.8°	n = 46 78% female Mean age: 18 y Age range 12–22 y Cobb angle: 28.8°	SRS-22 questionnaire
Parent et al (2009) 9	Prospective cohort April 2004–May 2005	N = 139 100% female Age range: 8–20 y	n = 32 Mean age: 16.5 ± 6.0 Brace type and length of time worn daily: NR Cobb angle: 36.6° ± 9.4°	n = 107 Mean age: 17.2 ± 7.7 Cobb angle: 33.0° ± 17.2°	SRS-22 questionnaire
Mannherz et al. (1988)10	Retrospective cohort 1940–1986	N = 43 79% female Mean age: 7 y Cobb angle: 21°	n = 31/32 (1 patient refused brace) 75% female Age: NR Milwaukee brace or localizer jacket used 23 ½ h daily Cobb angle: 22°	n = 11 91% female Age: NR Cobb angle: 11°	Surgery rate
Pham et al. (2008)11	Prospective cohort	N = 73 90% female Mean age: at presentation 7 y; at skeletal maturity 16.5 y	n = 41 88% female Mean age: 13.3 y ± 1.4 Chêneau Brace to be worn 23 h daily Cobb angle: 30.5° ± 3.1 n = 35 part-time (only at night) brace-wearing group not included in analysis	n = 32 94% female Mean age: 12.5 y ± 1.4 Cobb angle: 26.5° ± 2.4	Quality of Life Profile for Spine Deformities (QLPSD) Visual Analog Scale (VAS) for pain and quality of life
Ugwonali et al. (2004)12	Prospective cohort	N = 214 81% female Age range: 10.1–17.7 y	N = 78 81% female Mean age: 13.6 y Age range: 10.5–16.7 y Brace type and length of time worn daily: NR Cobb angle: 34.5°	N = 136 81% female Mean age: 13.8 y Age range: 10.1–17.7 y Cobb angle: 24.6°	Child Health Questionnaire (CHQ) Pediatric Outcomes Data Collection Instrument (PODCI)