{"uid":"cap_CuRxbQdmisv3COk-0UlTs","slug":"nunn-gregg-1989-predicted-peak-expiratory-flow-calculator-49043c64","name":"Nunn & Gregg 1989 Predicted Peak Expiratory Flow Calculator","description":"Nunn and Gregg 1989 predicted adult peak expiratory flow (L/min) from age, sex, and height. Sex-specific ln(PEF) regressions as published. Deterministic published arithmetic with citation; not a personal-best or action-plan zone.","url":"https://api.magentlab.com/api/calc/peak_expiratory_flow","method":"GET","headers":{},"bodySchema":{"type":"object","$schema":"https://json-schema.org/draft/2020-12/schema","required":["input"],"properties":{"input":{"type":"object","required":["type","method"],"properties":{"type":{"type":"string","const":"http"},"method":{"enum":["GET","HEAD","DELETE"],"type":"string"},"headers":{"type":"object","additionalProperties":{"type":"string"}},"queryParams":{"type":"object","required":["age","sex"],"properties":{"age":{"type":"integer","description":"Age in years (integer 15-85). Nunn and Gregg 1989 adult range."},"sex":{"enum":["female","male"],"type":"string","description":"Sex for the published regression (female or male)."},"height_cm":{"type":"number","description":"Height in centimetres (50-250). Provide height_cm or height_in."},"height_in":{"type":"number","description":"Height in inches (20-98). Converted as cm = in × 2.54."}}}},"additionalProperties":false},"output":{"type":"object","required":["type"],"properties":{"type":{"type":"string"},"example":{"type":"object"}}}}},"responseSchema":{"type":"json","example":{"path":"/api/calc/peak_expiratory_flow","count":2,"items":[{"sex":"male","formula":"nunn_gregg_1989","citation":{"id":"nunn-gregg-1989","doi":"10.1136/bmj.298.6680.1068","title":"New regression equations for predicting peak expiratory flow in adults","source":"BMJ. 1989;298(6680):1068-1070","authors":"Nunn AJ, Gregg I"},"age_years":40,"height_cm":175,"disclaimer":"Not a medical device. Deterministic published-formula or published-code output for autonomous agents. A licensed clinician remains responsible for patient care and billing submissions.","formula_expression":"ln(PEF_l_min) = a*ln(age) + b*age + c/height_cm + d; male a=0.544 b=-0.0151 c=-74.7 d=5.48; female a=0.376 b=-0.0120 c=-58.8 d=5.63","predicted_pef_l_min":636},{"sex":"male","formula":"nunn_gregg_1989","citation":{"id":"nunn-gregg-1989","doi":"10.1136/bmj.298.6680.1068","title":"New regression equations for predicting peak expiratory flow in adults","source":"BMJ. 1989;298(6680):1068-1070","authors":"Nunn AJ, Gregg I"},"age_years":40,"height_cm":175,"disclaimer":"Not a medical device. Deterministic published-formula or published-code output for autonomous agents. A licensed clinician remains responsible for patient care and billing submissions.","formula_expression":"ln(PEF_l_min) = a*ln(age) + b*age + c/height_cm + d; male a=0.544 b=-0.0151 c=-74.7 d=5.48; female a=0.376 b=-0.0120 c=-58.8 d=5.63","predicted_pef_l_min":636}]}},"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.005","displayCostAsset":"USDC","priceDynamic":false,"priceHint":null,"priceStatus":"priced","priceSource":"probe","requiresHandshake":false,"reviewCount":0,"rating":{"score":"0.00","successRate":"0.00","reviews":0,"stars":null,"state":"unrated"},"availabilityStatus":"unknown","priceObserved":null,"sessionDeposit":null,"pricing":{"kind":"static","summary":"$0.005/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.005","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.005","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_D2gwO3r9M_tyAFvU0QPOJ","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.005","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Calculates predicted adult peak expiratory flow (L/min) using the Nunn and Gregg 1989 sex-specific logarithmic regression from age, sex, and height","exampleAgentPrompt":"Using the Nunn and Gregg 1989 regression, what is the predicted peak expiratory flow for a 45-year-old male who is 178 cm tall?","exampleUseCases":[{"title":"Asthma baseline reference PEF","prompt":"What is the predicted normal peak expiratory flow for a 32-year-old female who is 165 cm tall? I need the Nunn and Gregg 1989 reference value to set her personal best baseline."},{"title":"Spirometry percent-predicted calculation","prompt":"My patient is a 58-year-old male, 180 cm tall, and his measured PEF is 480 L/min. Can you calculate his predicted PEF using the 1989 Nunn and Gregg formula so I can work out his percent predicted?"},{"title":"Occupational health PEF screening","prompt":"I have a 67-year-old female worker, height 5 feet 4 inches — what does the Nunn and Gregg 1989 regression predict her peak flow should be?"}],"resultDescription":"Returns the predicted peak expiratory flow in L/min computed from the sex-specific ln(PEF) regression published by Nunn and Gregg in 1989, given the patient's age and height. This is a reference/normative value, not a personal-best or action-plan zone.","failureModes":["Age outside the supported adult range (15–85 years) returns an error or out-of-range response","Height outside 50–250 cm (or 20–98 in) may be rejected as invalid","Missing required parameters (age or sex) returns a validation error","Invalid sex value (anything other than 'male' or 'female') returns an error","Neither height_cm nor height_in provided may cause a missing-parameter error"],"whenToPreferThis":"Use this endpoint when you need the published Nunn and Gregg 1989 normative PEF reference value for an adult patient given age, sex, and height — particularly for spirometry interpretation, percent-predicted calculations, or occupational/research contexts requiring a specific cited regression. It is deterministic and citable. Do not use it for personal-best PEF targets, action-plan zone thresholds, or pediatric patients.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-09-15T01:06:10.080Z","isFirstParty":false}