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. Author manuscript; available in PMC: 2010 Aug 31.
Published in final edited form as: N Engl J Med. 2009 Aug 6;361(6):569–579. doi: 10.1056/NEJMoa0900563

Table 1.

Baseline Characteristics of Study Participants.

Characteristic Vertebroplasty (N=68) Control (N=63)
Study Recruitment Site - no. (%)
 Mayo Clinic 14 (21%) 16 (26%)
 United Kingdom 26 (38%) 26 (41%)
 Australia 13 (19%) 9 (14%)
 USA (Non-Mayo Clinic) 15 (22%) 12 (19%)
Age - mean yr (sd) 73.4 (9.4) 74.3 (9.6)
White - no. (%) 67 (99%) 60 (95%)
Female - no. (%) 53 (78%) 46 (73%)
Education - no. (%)
 Less than high school 36 (53%) 26 (41%)
 High school 13 (19%) 23 (37%)
 Some college 10 (15%) 7 (11%)
 College graduate 9 (13%) 7 (11%)
Married or living with other - no. (%) 42 (62%) 27 (43%)
Employment - no. (%)
 Full/Part Time 7 (10%) 5 (8%)
 Retired 42 (62%) 39 (62%)
 Disabled 10 (15%) 10 (16%)
 Other 9 (13%) 9 (14%)
Smoker - no. (%) 12 (18%) 9 (14%)
Comorbidity index15 (0–28) - mean (sd) 1.9 (2.1) 2.0 (1.9)
Workers’ compensation - no. (%) 9 (13%) 7 (11%)
Pain duration (weeks) - no. (%)
 1 – 13 30 (38%) 24 (44%)
 14 – 26 14 (24%) 15 (21%)
 27 – 39 8 (14%) 9 (12%)
 40 – 52 16 (24%) 15 (23%)
median weeks (IQR) 16 (10 – 36) 20 (8 – 38)
Number of levels treated – no. (%)
 1 48 (71%) 41 (65%)
 2 13 (19%) 14 (22%)
 3 7 (10%) 8 (13%)
Self-Reported Opioid Analgesic Use – no. (%) 38 (56%) 40 (63%)
RDQ* – mean (sd) 16.6 (3.8) 17.5 (4.1)
Average Pain Intensity last 24 hours - mean (sd) 6.9 (2.0) 7.2 (1.8)

SF-36 (v2) - mean (sd)
 Physical Component Summary§ 25.3 (7.8) 25.3 (7.3)
 Mental Component Summary§ 44.8 (11.8) 41.5 (14.1)
Pain Frequency Index - mean (sd) 3.0 (0.8) 3.1 (0.8)
Pain Bothersome Index - mean (sd) 2.9 (0.7) 3.1 (0.8)
EQ-5D** - mean (sd) 0.57 (0.18) 0.54 (0.23)
SOF-ADL†† - mean (sd) 10.0 (3.6) 10.3 (2.8)
*

RDQ ranges from 0 to 23 with higher scores indicating worse physical disability.

Average Pain Intensity ranges from 0 = ‘no pain’ to 10 = ‘pain as bad as could be’.

§

Norm-based SF-36 (v2) scores are presented. In a healthy population, SF-36 scores have a mean of 50 and standard deviation of 10 with lower scores indicating worse outcome.

Pain Frequency and Bothersome indices range from 0 to 4 (4 = worst pain).

**

EQ-5D ranges from −0.1 to 1.0 with higher scores indicating better health.

††

SOF-ADL scores range from 0 to 18 with higher scores indicating more back-related disability.