Calcium (Ca)


Cotlove E, Harris EK and Williams GZ, 1970, Clin Chem, 16, 1028-32 , Biological and analytic components of variation in long-term studies of serum constituents in normal subjects


Total Score


Parameter Score
1. Scale A
2. Study Population A
3. Samples A
4. Measurand A
5. Pre-Analytical A
6. Replicate Analysis A
7. Steady State B
8. Outlier Analysis C
9. Normality B
10. Variance Homogeneity C
12. CI A
13. No of Results C
14. Concentrations A
15. Total Score C8,10,13

Item Details

Parameter Score
Matrix Serum
Measurand Calcium (Ca)
Unit mmol / L
Overall Analytical Principle Method Unknown
Number of Subjects 68
Number of Subjects included in BV estimation 68
Ethinicity Mixed
Age Mean / Median
Age Min 30.0
Age Max 32.0
Age SD
Number of Males 33
Number of Females 35
State of Well Being
Healthy (excl pregnant)
Study Duration Length 39
Study Duration Units Month
Sampling Intervals, e.g. X sample(s) per Interval Unit 12
Interval Units Week
Sampling Times Start Time: 08:30
End Time: 09:00
Number of Samples 3
Average Number of Samples Used for BV Estimation 3.0
Average Number of Replicates 2.0
Estimates of CVi 3.8
Calculated Confidence Intervals of CVi Lower: 3.22, Upper: 4.49
Estimates of CVg 4.7
Calculated Confidence Intervals of CVg Lower: 3.77, Upper: 5.90
Analytical CV 3.2
Calculated Confidence Intervals of Analytical CV Lower: 2.92, Upper: 3.54
Measurand Mean 2.55
Measurand Min
Measurand Max
Measurand SD 0.12