Age and gender plays should be taken into account when interpreting the values of ESR and CRP. The maximum ESR value is limited by the length of the Westergren tube (usually 120 mm), but the CRP has no upper limit.
Miller formulae for calculating maximum normal ESR in Adults
ESR is higher in women than men and correlates significantly with advancing age. For patients who are the same age, the ESR, by the Miller formula, should be 5 mm/h higher in women than men.
- Men: Age/2
- Women: (Age + 10)/2
Miller formulae for calculating maximum normal CRP in Adults
Some studies have shown that serum CRP levels are neither affected by the gender of the patient or by their age and do not require adjustment for gender or age.
- Men: Age/50
- Women: Age/50 + 0.6 OR (Age + 30)/50
- Miller A, Green M, Robinson D. Simple rule for calculating normal erythrocyte sedimentation rate. Br Med J (Clin Res Ed). 1983 Jan 22;286(6361):266. doi: 10.1136/bmj.286.6361.266. PMID: 6402065; PMCID: PMC1546487.
- Wener MH, Daum PR, McQuillan GM. The influence of age, sex, and race on the upper reference limit of serum C-reactive protein concentration. J Rheumatol. 2000 Oct;27(10):2351-9. PMID: 11036829.