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Table 1 Final multivariable Cox regression model for variables associated with active episodes of owner-reported laminitis (n = 100) in a cohort of British horses and ponies (n = 978 horses/ponies providing 6390 observations and a cumulative time of 974 HYAR after exclusions for missing data)

From: Identification of modifiable factors associated with owner-reported equine laminitis in Britain using a web-based cohort study approach

Variable No. laminitis episodes HYAR/100 Hazard ratio 95% CI Wald
P-value
LRS
P-value
Animal-level factors
Weight change since last entry       0.003
  Weight lost/maintained 68 7.6 Ref.    
  Weight gained 30 2.0 2.3 1.4, 3.8 < 0.001  
  Not specified 2 0.1 1.8 0.4, 8.0 0.44  
Breed category (including breed crosses)      0.007
  Native pony 65 3.8 1.9 1.2, 3.0 0.007  
  Other breed 35 5.9 Ref.    
Laminitis history
Previous laminitis while with current owner      < 0.001
  No 23 6.4 Ref.    
  Yes, veterinary-diagnosed 44 2.4 1.7 0.8, 3.8 0.15  
  Yes, not veterinary-diagnosed 33 0.9 4.5 2.2, 9.1 < 0.001  
Time taken to return to soundness following most recent episode   0.002
  0 to 2 weeks 38 7.4 Ref.    
  More than 2 weeks to 2 months 32 1.3 2.0 1.0, 3.8 0.04  
  More than 2 months 30 1.0 3.1 1.6, 6.2 0.001  
Health management and recent health history
Currently on steroidal anti-inflammatories      0.03
  No 96 9.6 Ref.    
  Yes 4 0.1 4.0 1.4, 11.6 0.01  
Currently on non-steroidal anti-inflammatories    < 0.001
  No 77 8.9 Ref.    
  Yes 23 0.8 2.9 1.7, 4.8 < 0.001  
Current lameness       0.02
  Other lameness/no lameness 95 9.6 Ref.    
  Soft tissue injury (e.g. tendon/ligament) 5 0.2 4.1 1.5, 10.8 0.005  
Active wormer ingredients in last wormer given    0.003
  Macrocyclic lactones 19 2.4 Ref.    
  Benzimidazoles 15 0.5 3.8 1.8, 8.1 < 0.001  
  Other/no wormer 66 6.8 1.3 0.7, 2.2 0.39  
Hoof care
Lameness/soreness following routine hoof care    0.004
  Not lame/sore after shoeing/trimming 83 9.3 Ref.    
  Lame/sore after shoeing/trimming 17 0.4 2.5 1.4, 4.4 0.002  
Trimming/shoeing frequency       0.03
  Up to 8 weeks 80 8.3 Ref.    
  More than 8 weeks 20 1.4 1.9 1.1, 3.2 0.02  
Turnout and grazing management
Time of day access to grass currently available    0.007
  Morning only 9 0.4 4.3 1.8, 10.8 0.002  
  Day and night 28 4.7 Ref.    
  Other/grass not available 63 4.7 1.4 0.7, 2.8 0.28  
Grazing muzzle use       0.001
  Whole time while grazing/not used 89 9.5 Ref.    
  Part of the time while grazing 11 0.3 3.6 1.8, 7.2 < 0.001  
Woodland bordering turnout area       0.007
  No/entirely stabled 82 7.1 Ref.    
  Yes 18 2.6 0.5 0.3, 0.9 0.01  
Main reason for transport in the previous year      0.001
  Other reason/not transported 82 8.7 Ref.    
  Moving yards 18 1.0 2.6 1.5, 4.5 < 0.001  
Average time currently spent stabled       < 0.001
  Up to 12 h 46 2.7 3.2 1.7, 5.9 < 0.001  
  More than 12 h 19 2.1 Ref.    
  Free access/not stabled 35 4.9 1.7 0.8, 3.7 0.15  
Supplementary feeding
Ryegrass forage fed       < 0.001
  Other/no forage fed 91 9.3 Ref.    
  Yes 9 0.5 4.7 2.2, 10.0 < 0.001  
  1. HYAR Horse-years at risk, LRS Likelihood ratio statistic, Ref. Referent group in which the Hazard Ratio = 1.0; 95% CI – 95% Confidence Interval