Kharbanda et al reported a Pediatric Appendicitis Risk Calculator (pARC) for evaluating a pediatric patient for appendicitis. The authors are from Children's Minnesota, HealthPartners Institute, Kaiser Permanente Oakland, Boston Children's Hospital, Harvard Medical School, Columbia University and University of California Davis.
Patient selection: pediatric patient with possible appendicitis, from 5 to 18 years
Parameters:
(1) sex
(2) age and sex
(3) duration of pain in hours
(4) presence of pain while working
(5) history of pain migration to right lower quadrant (RLQ)
(6) maximal abdominal tenderness located over right lower quadrant
(7) abdominal guarding
(8) absolute neutrophil count (ANC)
|
Parameter
|
Finding
|
Points
|
|
sex
|
female
|
0
|
|
|
male
|
1.28
|
|
age and sex
|
female 5 to 7.9 years
|
0.38
|
|
|
female 8 to 11.9 years
|
-0.72
|
|
|
female 12 to 18 years
|
0
|
|
|
male and 5 to 7.9 years
|
-0.67 (0.38-1.05)
|
|
|
male 8 to 13.9 years
|
-0.72
|
|
|
male 14 to 18 years
|
0
|
|
duration of pain
|
< 24 hours
|
0
|
|
|
24 to 47.99 hours
|
0.47
|
|
|
48 to 96 hours
|
0.1
|
|
pain while walking
|
no
|
0
|
|
|
yes
|
1.05
|
|
pain migration to RLQ
|
no
|
0
|
|
|
yes
|
0.46
|
|
max tenderness RLQ
|
no
|
0
|
|
|
yes
|
1.14
|
|
abdominal guarding
|
no
|
0
|
|
|
yes
|
0.67
|
|
absolute neutrophil count
|
< 14 * 10^3 per µL
|
1.77 * SQRT(ANC)
|
|
|
>= 14 * 10^3 per µL
|
6.62
|
where:
• Table 3 is ambiguous for the beta-coefficient for a male 5 to 7.9 years. The value above is based on comparison of the score to results shown in Cotton et al, Table 3.
• The square root for the ANC is taken of the coefficient.
• 1.77 * SQRT(14) = 6.62
value of X =
= SUM(points for all 8 parameters) - 8.7
probability of appendicitis =
= 1 / (1 + EXP((-1) * X))
Performance:
• The area under the ROC curve in the validation cohort was 0.85.
