Supplement Brief articles are written for a general audience and audited with standard readability metrics. This page shows how each guide scores and what rules we follow to keep the writing accessible.
Target reading level
Supplement Brief articles target a US grade 8 to 10 reading level (approximately age 13 to 16). This follows NIH Clear Communication guidance and AHRQ plain-language standards for consumer health materials. Health information that a reader cannot parse is not accessible, regardless of how strong the underlying evidence is.
Current corpus average sits at the upper end of that band (see the snapshot below). SMOG runs about two grades higher than Flesch-Kincaid because it weights polysyllabic medical and chemical terms more heavily; this is the known behavior of SMOG on health content and is the reason we track both rather than relying on a single score. Guides that exceed grade 12 on either metric are flagged for editorial review and revision before the next publication cycle.
What we measure
Reading time — word count divided by 200 words per minute.
Flesch Reading Ease — 0 to 100, higher is easier.
Flesch-Kincaid Grade — US school grade needed to read the text.
SMOG Index — grade estimate weighted toward complex (3+ syllable) words. Most conservative for health content.
Complex-word ratio — share of words with three or more syllables.
Editorial rules that keep readability high
No unexplained jargon. Every technical term gets an inline gloss.
Short sentences when the claim is consequential.
Numbered decision frameworks instead of prose paragraphs when the reader needs to act.
Sources cited inline, not buried in a footnote wall.
Trade names and chemical names are paired with a plain-language label on first use.
Target band (grade 8–10), current corpus average (10.1), and the flag threshold at grade 12. Guides above 12 on either Flesch–Kincaid or SMOG are revised before the next publication cycle.
Corpus snapshot
Across 26 published guides:
102,948 total words; 3,960 average per guide.
Average Flesch-Kincaid grade: 10.1.
Average SMOG index: 13.
Average Flesch Reading Ease: 49.2 (difficult).
Average complex-word ratio: 20.31%.
Per-article metrics
Sorted by Flesch-Kincaid grade, most demanding first. Metrics are calculated automatically from the published article text to ensure every guide is measured using the same process. On mobile the breakdown is collapsed by default; tap to expand.
A Flesch-Kincaid grade of 9 means a typical US 9th grader can read it without stopping. A SMOG index of 10 means roughly 10 years of formal education to fully comprehend. SMOG is usually 1 to 2 grades higher than Flesch-Kincaid because it weights polysyllabic words more heavily; this is expected and not a sign of failure. Health content that scores above grade 12 on either metric is flagged for editorial review. New guides that exceed the target range are revised before publication.
