TIRE - normative values calculator · Czech population (Central Europe)
Normative values & LLN (lower limit of normal)
Based on the parameters entered, the calculator determines normative values for individuals for SMIP and SMEP and their LLN (lower limit of normal, corresponding to the 5th percentile), which defines the threshold below which the value is considered "abnormally low" and may indicate pathological changes. The "Percentile" value indicates the percentile in which the measured person is located in relation to the normative value of the healthy population.
Enter the parameters
Use the best result from 3–5 attempts.
Use the best result from 3–5 attempts.
For a reliable assessment of these parameters, it is recommended to perform 3-5 attempts and evaluate the best result achieved.
As part of the diagnosis, it is also necessary to take into account the clinical context and other factors that may influence the measured results for a given individual.
SMIPmeas and SMEPmeas represent the measured/entered values. Percentile is calculated as a quantile in the range 0–1 and is displayed as a percent value by multiplying by 100.
Model ranges. The models were built on data with the following ranges:
women: age 22–80 years, height 151–184 cm;
men: age 21–80 years, height 164–196 cm.
For age and height outside these ranges, the models may not provide reliable estimates (extrapolation). Values near the boundaries (e.g. woman 20 years, 149 cm) may still be acceptable; further outside (e.g. woman 15 years) the results can be substantially off.
Results
SMIP normative value
—
— PTU
LLN of SMIP (5th perc.)
— PTU
Percentile
—
SMEP normative value
—
— PTU
LLN of SMEP (5th perc.)
— PTU
Percentile
—
Figure for illustration only: it shows the meaning of the outputs above (norm. value, LLN, percentile). The percentile is the area under the curve to the left of the measured value (the blue shaded region in the figure).
Equations
The equations below are taken from the provided specification. Height is in cm, age in years, SMIP/SMEP in PTU.
Predicted
SMIPpred = -327.6031 + 15.9085·age − 0.2001·age² + 3.4880·heightLLN (5th percentile)
LLN = SMIPpred − t(0.95,57)·(89841.5837 − 545.8638·age + 16.9739·age² − 0.2502·age³ + 0.001173·age⁴ − 967.2954·height + 2.8680·height² − 0.6538·age·height + 0.014970·age²·height + 949.3231·exp(0.003983·SMIPpred))^0.5Percentile
F_t[(SMIPmeas−SMIPpred)/(89841.5837 − 545.8638·age + 16.9739·age² − 0.2502·age³ + 0.001173·age⁴ − 967.2954·height + 2.8680·height² − 0.6538·age·height + 0.014970·age²·height + 949.3231·exp(0.003983·SMIPpred))^0.5; 57]Predicted
SMIPpred = -692.0877 − 0.05165·age² + 9.2439·heightLLN (5th percentile)
LLN = SMIPpred − t(0.95,56)·(329906.6655 − 9.3624·age² + 0.0001744·age⁴ − 3522.5018·height + 9.4525·height² + 0.04600·age²·height + 3267.0720·exp(0.002508·SMIPpred))^0.5Percentile
F_t[(SMIPmeas−SMIPpred)/(329906.6655 − 9.3624·age² + 0.0001744·age⁴ − 3522.5018·height + 9.4525·height² + 0.04600·age²·height + 3267.0720·exp(0.002508·SMIPpred))^0.5; 56]Predicted
SMEPpred = -747.0736 + 16.3981·age − 0.2203·age² + 7.8440·heightLLN (5th percentile)
LLN = SMEPpred − t(0.95,57)·117.5947·(15.6211 − 0.08600·age + 0.002689·age² − 0.00004094·age³ + 0.0000002013·age⁴ − 0.1579·height + 0.0004647·height² − 0.00007934·age·height + 0.000002208·age²·height)^0.5Percentile
F_t[(SMEPmeas−SMEPpred)/(117.5947·(15.6211 − 0.08600·age + 0.002689·age² − 0.00004094·age³ + 0.0000002013·age⁴ − 0.1579·height + 0.0004647·height² − 0.00007934·age·height + 0.000002208·age²·height)^0.5); 57]Predicted
SMEPpred = -406.8848 + 24.9355·age − 0.3341·age² + 7.6430·heightLLN (5th percentile)
LLN = SMEPpred − t(0.95,56)·218.4923·(15.2243 − 0.04080·age + 0.002673·age² − 0.00005104·age³ + 0.0000002562·age⁴ − 0.1470·height + 0.0004221·height² − 0.0004366·age·height + 0.000005936·age²·height)^0.5Percentile
F_t[(SMEPmeas−SMEPpred)/(218.4923·(15.2243 − 0.04080·age + 0.002673·age² − 0.00005104·age³ + 0.0000002562·age⁴ − 0.1470·height + 0.0004221·height² − 0.0004366·age·height + 0.000005936·age²·height)^0.5); 56]
t(0.95,57)=1.6720; t(0.95,56)=1.6725.