Crowson et al developed a score for predicting the risk of a serious infection in a patient with rheumatoid arthritis. A patient at increased risk may benefit from interventions to reduce this risk. The authors are from the Mayo Clinic in Rochester.
Patient selection: rheumatoid arthritis
Outcome: serious infection (requires hospitalization and/or intravenous antibiotics)
Parameters:
(1) age in years
(2) history of a previous serious infection
(3) extra-articular manifestations of RA (amyloidosis, Felty’s syndrome, rheumatoid vasculitis, rheumatoid lung disease)
(4) erythrocyte sedimentation rate (ESR) in mm/h
(5) corticosteroid therapy in mg per day
(6) comorbidities (diabetes mellitus, chronic lung disease, alcoholism, coronary heart disease, heart failure, peripheral vascular disease)
|
Parameters
|
Findings
|
Points
|
|
age in years
|
< 60 years of age
|
0
|
|
|
60 to 79 years of age
|
0.404
|
|
|
>= 80 years of age
|
0.857
|
|
previous serious infection
|
none
|
0
|
|
|
> 3 years ago
|
0
|
|
|
in past 2-3 years
|
1.670
|
|
|
in past year
|
2.138
|
|
extra-articular manifestations
|
absent
|
0
|
|
|
present
|
0.620
|
|
ESR
|
< 30 mm/h
|
0
|
|
|
30 to 50 mm/h
|
0.180
|
|
|
> 50 mm/h
|
0.611
|
|
corticosteroid therapy
|
none
|
0
|
|
|
<= 10 mg/day
|
0.553
|
|
|
> 10 mg/day
|
1.281
|
|
comorbidities
|
0
|
0
|
|
|
1
|
0.675
|
|
|
>= 2
|
1.024
|
total score =
= SUM(points for all 6 parameters)
probability of a serious infection within the next year in percent =
= (1 – (0.989^(EXP(score)))) * 100%
Limitations:
• Other conditions could be significant such as immunodeficieincy or cancer.
• The study was performed before widespread use of targeted therapy.
