Pilon VA, Howanitz PJ, Howanitz JH and Domres N, 1991, Clin Chem, 27, 78-82 , Day-to-day variation in serum ferritin concentration in healthy subjects


Total Score


Parameter Score
1. Scale A
2. Study Population A
3. Samples A
4. Measurand A
5. Pre-Analytical C
6. Replicate Analysis B
7. Steady State B
8. Outlier Analysis C
9. Normality B
10. Variance Homogeneity C
12. CI C
13. No of Results C
14. Concentrations B
15. Total Score C5,8,10,11,12,13

Item Details

Parameter Score
Matrix Serum
Measurand Ferritin
Unit ug / L
Overall Analytical Principle Method Immunoassay; RIA
Number of Subjects 13
Number of Subjects included in BV estimation 13
Ethinicity Caucasian
Age Mean / Median
Age Min 25.0
Age Max 39.0
Age SD
Number of Males 5
Number of Females 8
State of Well Being
Healthy (excl pregnant)
Study Duration Length 5
Study Duration Units Week
Sampling Intervals, e.g. X sample(s) per Interval Unit 1
Interval Units Day
Sampling Times Start Time: same time in the morning
End Time: same time in the morning
Number of Samples 15
Average Number of Samples Used for BV Estimation 14.4
Average Number of Replicates 2.0
Estimates of CVi 14.5
Calculated Confidence Intervals of CVi Lower: 13.06, Upper: 16.27
Estimates of CVg
Calculated Confidence Intervals of CVg Lower: , Upper:
Analytical CV 4.3
Calculated Confidence Intervals of Analytical CV Lower: 3.90, Upper: 4.79
Measurand Mean
Measurand Min
Measurand Max
Measurand SD