How does the age of a patient affect the interpretation of Erythrocyte Sedimentation Rate (ESR) results?

Age-Related Changes in Erythrocyte Sedimentation Rate (ESR) Interpretation

The erythrocyte sedimentation rate (ESR) increases with age, and age-adjusted reference ranges should be used when interpreting ESR results to avoid misdiagnosis and unnecessary investigations.

Normal ESR Values by Age

• Young adults (under 40 years):

  • Normal range: 0-25 mm/hr for both males and females 1

• Middle-aged adults (40-60 years):

  • Progressive increase with age
  • Mean of 18 mm/hr (range 0-35) by age 60 1

• Elderly patients (over 60 years):

  • Further increases with advancing age
  • ESR values up to 35-40 mm/hr may be normal in healthy elderly persons 2
  • Studies of healthy elderly (70-89 years) show mean ESR of 13-14 mm/hr with ranges extending up to 65-69 mm/hr 3

Clinical Formula for Age-Adjusted ESR

A commonly used formula for estimating the upper limit of normal ESR:

• For men: Age in years ÷ 2
• For women: (Age in years + 10) ÷ 2

Implications for Clinical Practice

Diagnostic Considerations

• An elevated ESR in elderly patients should be interpreted with caution
• ESR lacks specificity and cannot differentiate between numerous conditions 4
• In about 25% of elderly patients with confirmed disease (both malignant and non-malignant), ESR remains below 20 mm/hr 2
• Despite age-related increases, a markedly elevated ESR (>50 mm/hr) at any age warrants investigation as it is associated with significantly higher mortality risk (HR 1.89,95% CI 1.38-2.60) 5

Disease-Specific Considerations

• Giant Cell Arteritis/Temporal Arteritis: ESR >100 mm/hr has a positive likelihood ratio of 3.11 4
• Inflammatory conditions: Moderate ESR elevation suggests chronic inflammatory conditions, while marked elevation strongly suggests significant underlying pathology 4
• Malignancy: Despite age-related increases, 26% of patients with malignant disease may have ESR <20 mm/hr 2

Clinical Approach to Elevated ESR in Elderly

1. Consider the degree of elevation:

   • Mild elevation (slightly above age-adjusted normal): Often non-specific or age-related
   • Moderate elevation (20-50 mm/hr): May suggest chronic inflammatory conditions
   • Marked elevation (>50 mm/hr): Strongly suggests significant underlying pathology

2. Interpret in clinical context:

   • Combine with other inflammatory markers (particularly CRP)
   • CRP is less affected by age than ESR 1
   • Consider disease-specific markers for suspected conditions

Limitations of ESR in the Elderly

• Limited diagnostic value in elderly patients 3
• Poor specificity - elevated values may be consistent with continued good health 3
• ESR may remain elevated even after resolution of acute inflammation 1
• May be normal despite serious disease in approximately 25% of cases 2

Practical Recommendations

• Always use age-adjusted reference ranges when interpreting ESR results
• Consider parallel testing with CRP, which is less affected by age
• In elderly patients with elevated ESR but no clinical symptoms, close monitoring may be more appropriate than extensive investigations
• Even in asymptomatic elderly patients over 75 years without comorbidities, an ESR >20 mm/hr is associated with increased mortality risk (HR 1.29,95% CI 1.01-1.64) and warrants follow-up 5