How the ideal body weight formulas compare from short heights to tall
Four published ideal body weight formulas turn height and sex into one weight, and they were written as drug-dosing and...
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CURB-65 death rates checked against the paper that defined the score
CURB-65 grades community-acquired pneumonia in adults with one point each for confusion, raised urea, fast breathing, lo...
Field-test formulas for VO2 max put the same run at very different values
Field tests estimate VO2 max, the most oxygen the body can use per minute for each kilogram of body weight, from a timed...
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Naegele's rule and the 280-day count give different pregnancy due dates more often than not
A due date is counted from the first day of the last period, either by adding 280 days or by adding nine months and seve...
Glasgow Coma Scale totals hide the eye, verbal and motor scores behind them
A Glasgow Coma Scale total adds three separate observations of the eyes, speech and movement, and the same total can be...
Equations estimating a one-repetition maximum match on heavy sets and diverge as reps climb
A one-rep max is the heaviest weight a person can lift once, and published equations estimate it from a lighter set take...
The usual mid-parental height range missed 12% of Galton's grown children
The usual target height averages the parents' heights, shifts the result 6.5 cm for sex and allows 8.5 cm either side. I...
Calculated LDL reads lower on Friedewald's formula than on Martin-Hopkins at high triglycerides
A calculated LDL is total cholesterol minus HDL minus an estimate of the cholesterol in VLDL, and the Friedewald, Martin...
Dropping the sex point from the AF stroke score moved no combination between bands
In 2024 the European Society of Cardiology replaced the CHA2DS2-VASc stroke score for atrial fibrillation with CHA2DS2-V...
A bathroom scale's rounding can shift a sweat-rate test by a tenth of a litre an hour
Sweat rate is body weight before exercise minus weight after, plus fluid drunk, minus urine, divided by the hours. On a...
QT correction formulas agree at 60 beats a minute and drift apart either side
Bazett, Fridericia and Framingham correct the QT interval to a heart rate of 60 beats a minute, where all three give the...
A baby's growth percentile depends on the chart behind it
A growth percentile ranks one measurement against a reference group of children, and the WHO 2006 standard, the US CDC 2...
Colour-blindness simulators give their least consistent answers on blue and yellow
A colour-blindness simulator runs each pixel through a published model of colour-vision deficiency. We compared the thre...
How many weeks you have left, by Singapore and Malaysian life tables
A Singapore resident aged 65 can expect about 1,127 more weeks on the 2025 life tables, 141 more than the figure at birt...
How accurate is the Chinese gender chart, and why versions disagree
A test on 2.8 million Swedish births found the Chinese gender chart no better than a coin toss, and simply guessing "boy...
The same blood pressure reading is hypertension in America and not in Singapore
135 over 85 is stage 1 hypertension under the American guideline, high-normal in Singapore, and hypertension again in Ta...
ASEAN requires an SPF number and no UVA rating at all
The regional labelling guideline devotes a single sentence to ultraviolet A, so a shelf in Singapore or Kuala Lumpur car...
A low-sugar drink can still get a Nutri-Grade D
Singapore's Nutri-Grade letter grades drinks on sugar and saturated fat, and the worse of the two sets the grade — so a...
Why processed meat and smoking sit in the same cancer group
IARC put processed meat in Group 1 alongside tobacco and asbestos, and the comparison has been repeated ever since. The...
Apple's earbuds protect your hearing in America and merely reduce loud sound in Singapore
The same silicon, running the same firmware. Apple calls the feature Hearing Protection in the US and Loud Sound Reducti...
Your osteoporosis diagnosis is scored against two different populations at once
The hip T-score is computed against a US survey of white women aged 20–29 measured in 1988–94; the spine T-score against...
The calcium formula everyone uses is not the one it cites
Corrected calcium is computed with a coefficient of 0.8 and attributed to Payne 1973 on virtually every clinical referen...
The Army stopped taping. The Marines did not.
Both services replaced the tape test with waist-to-height ratio in 2026 and then disagreed twice over. The Army set the...
The kidney formula in your drug label came from seven data points
The 1976 equation that still decides anticoagulant doses was fitted to seven averaged points, drawn from 249 men after h...
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