Reflux Body Log is a symptom-tracking tool, not a medical device. It does not diagnose, treat, or cure any condition. This page lists the published references behind the health and anatomy language used in the app and in the doctor-report PDF.
What this page covers
- The anatomical regions referenced on the body map (retrosternal, epigastric, laryngopharyngeal, lower abdominal).
- The 1–5 severity scale shown on the log screen and in the heatmap.
- The Apple Health metrics surfaced in the doctor-report PDF (sleep, resting heart rate, heart rate variability).
- The methodology and disclaimers that appear on page 3 of the exported PDF.
GERD overview and the value of symptom tracking
The app's framing — "track flares between gastroenterology appointments so the next consult is grounded in your real day-to-day data" — follows the patient education guidance published by major gastroenterology bodies.
- MedlinePlus — Gastroesophageal Reflux Disease (GERD) . U.S. National Library of Medicine, National Institutes of Health. Plain-language overview of GERD symptoms, common triggers, and when to seek care.
- American College of Gastroenterology — Acid Reflux / GERD . ACG patient education resource. Used as the reference for the language around symptom patterns and pre-consult preparation.
Anatomical regions on the body map
The four touchable regions on the body map use standard anatomical terminology: retrosternal (behind the breastbone), epigastric (upper abdomen, below the breastbone), laryngopharyngeal (throat / upper airway), and lower abdominal. The app does not perform any anatomical mapping beyond which region the user taps.
- MedlinePlus — GERD (anatomy and symptom location) . NIH/NLM. Source for the plain-language anatomical descriptions.
- ACG — Acid Reflux / GERD (regional symptom presentation) . Source for laryngopharyngeal ("throat") and epigastric presentations of reflux.
The 1–5 severity scale
The severity selector on the log screen is a self-reported numeric rating scale (NRS) with anchored endpoints: 1 = barely noticeable, didn't interrupt; 5 = severely interrupting daily activity or sleep. Numeric rating scales are an established self-report instrument for symptom intensity in adults; they are not a clinical assessment, and the app does not interpret the score as a diagnosis or severity grade.
- Hjermstad MJ, Fayers PM, Haugen DF, et al. Studies comparing Numerical Rating Scales, Verbal Rating Scales, and Visual Analogue Scales for assessment of pain intensity in adults: a systematic literature review . J Pain Symptom Manage. 2011 Jun;41(6):1073–93. PubMed PMID: 21621130.
Apple Health metrics in the doctor-report PDF
The PDF's "Apple Health window" section reads three metrics from Apple Health, with the user's explicit HealthKit permission: sleep duration, resting heart rate, and heart rate variability (HRV / SDNN). The app reports each value as Apple Health computes it — no recomputation, no smoothing, no derivation beyond windowed means and a same-length baseline comparison.
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Apple Developer — HKQuantityTypeIdentifier
. Canonical reference for HealthKit quantity identifiers used in the app:
restingHeartRateandheartRateVariabilitySDNN. - Apple Developer — HKCategoryTypeIdentifier.sleepAnalysis . Canonical reference for the sleep data read from Apple Health.
Trigger tags and methodology
Trigger tags (e.g. "coffee", "spicy", "late meal") are patient-selected at the time of each log and are optional. The "Most-tagged triggers" tile in the PDF ranks the top three tags by raw count across the export window. The relationship is observational: no confounders are adjusted for, and tag-to-flare association is not causal.
Methodology disclaimer
All summaries in the doctor-report PDF (heatmap aggregation, Apple Health windowing, trigger ranking) are descriptive — they describe what the user logged, not what is clinically true.
- The app is for tracking and educational purposes only and is not a medical device.
- The PDF is designed as a conversation aid for an appointment you have already booked, not as a substitute for clinical evaluation.
- The data shown is self-reported. It has not been validated against any clinical instrument or reference standard.
- Always consult a qualified clinician (gastroenterologist or primary care physician) before making any treatment decision.
Updates
If the app's medical language or methodology changes, this page will be updated and the "Last updated" date at the top revised. For questions about a specific reference or how a summary in the PDF was computed, email the address below.