Table 3

Risk factors for OP*†

AllRACTDVasculitidesSpondyloarthritides
N=1066N=434N=281N=173N=178
Disease activity
 HAQ score0.8 (±0.8)0.9 (±0.8)0.9 (±0.9)0.6 (±0.8)0.8 (±0.7)
 S-CRP mg/L (<5), median (IQR)2.3 (0.8–6.6)2.4 (0.8–6.7)1.6 (0.7–4.9)4.8 (1.3–10.9)2.0 (0.8–4.9)
 RA–DAS28–CRP score2.7 (±1.3)
  Disease duration (years)11.9 (±10)11.9 (±10)12.8 (±9)5.4 (±6)17.2 (±13)
  Use of care services‡473 (51)189 (49)147 (59)53 (36)84 (57)
Age (years)
 Age group
  <50164 (15)43 (10)80 (9)12 (7)29 (16)
  50–64427 (40)180 (42)103 (27)50 (29)94 (53)
  65–84458 (43)203 (47)97 (25)107 (62)51 (29)
  ≥8517 (2)8 (2)1 (<1)4 (2)4 (2)
 Underweight (BMI <18.5 kg/m²)28 (3)8 (2)18 (6)2 (1)0
Family history
 OP212 (27)100 (30)54 (25)22 (19)36 (33)
 Osteoporotic fractures101 (13)44 (14)28 (14)13 (11)16 (14)
Comedication
 Proton pump inhibitors468 (44)175 (40)138 (49)98 (57)57 (32)
 NSAIDs249 (23)117 (27)45 (16)14 (8)73 (41)
 Antidepressants75 (7)18 (4)38 (14)6 (4)13 (7)
 Oral antidiabetics61 (6)26 (6)4 (1)11 (6)20 (11)
 Insulin49 (4)19 (4)9 (3)9 (5)12 (7)
 Antihyperuricaemic drugs42 (4)18 (4)9 (3)8 (5)7 (4)
 Oestrogens (female patients only)17 (2)6 (1)7 (3)05 (5)
Concomitant diseases§
 Osteoarthritis153 (14)79 (18)38 (14)10 (6)26 (15)
 Diabetes130 (12)56 (13)16 (6)26 (15)32 (18)
 Dyslipidaemia119 (11)43 (10)32 (11)25 (15)19 (11)
 Depression94 (9)39 (9)27 (10)11 (6)17 (10)
 Renal insufficiency76 (7)21 (5)22 (8)25 (15)8 (5)
 Hyperuricaemia/gout53 (5)23 (5)12 (4)8 (5)10 (6)
  • *Categorical variables are presented as number and per cent of valid observations (%) unless otherwise noted.

  • †Continuous variables are presented as mean values with SD unless otherwise noted.

  • ‡Use of care services comprises any level of care received, including low-level support. The latter applied for most patients.

  • §Concomitant diseases: shown are diseases or medications that are either particularly common and/or variables considered to have a ‘weakly expected’ impact on the T-score. To avoid overfitting, diseases or medications were not considered in our model when case numbers were low (such as history of transplantation, chronic obstructive pulmonary disease, antiepileptic therapy, heart failure, aromatase inhibitors and hypogonadism).

  • BMI, body mass index; CTD, connective tissue diseases; HAQ, Health Assessment Questionnaire; NSAID, non-steroidal anti-inflammatory drug; OP, osteoporosis; RA, rheumatoid arthritis; S-CRP, serum C reactive protein.