WHY ENGLISH?
make an ATC/DDD drug-use study traceable from medicinal product packages to comparable population measures
Drug-use studies often convert millions of packages, prescriptions or dispensing records into comparable rates. English matters because ATC codes and Defined Daily Doses only become interpretable when authors report the code level, index year, route, product linkage, calculation, denominator and limitations.
EMMA is a proposed reporting checklist for drug-utilisation and pharmacoepidemiological studies using the WHO ATC/DDD methodology. EQUATOR records it as registered on 27 October 2026 and under development. It is intended to extend existing observational-study guidance rather than replace RECORD-PE or STaRT-RWE.
WHO defines the DDD as the assumed average maintenance dose per day for a drug used for its main indication in adults. It is a technical measurement unit, not necessarily a recommended or prescribed dose. The WHO Collaborating Centre updates the ATC index and DDDs annually; version and route therefore matter.
Article contents
Open all chapters
- 1. State the Drug-Use Question and Data Source
- 2. Name the ATC/DDD Index and Guidelines Version
- 3. Report the ATC Level and Selection Rules
- 4. Preserve Route of Administration
- 5. Link Medicinal Products to Active Substances
- 6. Report Strength, Quantity and Package Content
- 7. State the Official or Local DDD Value
- 8. Calculate DDDs per Package Transparently
- 9. Define Population and Time Denominators
- 10. Describe Inclusion, Exclusion and Missing Products
- 11. Track Code and DDD Changes Over Time
- 12. Validate Mappings and Calculations
- 13. Separate DDD From Prescribed Daily Dose
- 14. Handle Paediatric and Special Populations Carefully
- 15. Report Comparisons and Sensitivity Analyses
- 16. Conclude With Bounded Medicines-Use Claims
ORIENTATION
What this guide covers
Current fact check
ATC classifies active substances through five levels. A DDD is linked to an ATC code and route, and not every medicine has one. The 2026 ATC/DDD Index and Guidelines are current for this dated article. DDD-based rates provide rough comparative consumption measures rather than exact individual use.
What this guide does not cover
This article focuses on reporting ATC/DDD use in drug-utilisation and pharmacoepidemiological studies. It does not provide prescribing advice, convert DDD into an individual dose, replace the current WHO index, or invent final EMMA items.
Worked example
Every chapter returns to a fictional national study comparing oral antihypertensive dispensing across regions from 2023 to 2026. It is fictional, low-stakes and educational; it does not report a real school, clinical decision or guaranteed outcome.
Did You Know? For EMMA ATC/DDD drug-use reporting, complete reporting makes appraisal possible but does not perform the appraisal, remove bias or guarantee transfer.
Warm up with eduKate’s guides to explaining scientific evidence and asking better questions in class.
CHAPTER 1 OF 16
1. State the Drug-Use Question and Data Source
Why this move matters
Name population, medicines, place, period, data origin and whether records represent sales, dispensing, claims or prescriptions.
Did You Know? The question determines the appropriate numerator and denominator.
Translate packages into a comparable measurement trail
Name population, medicines, place, period, data origin and whether records represent sales, dispensing, claims or prescriptions. Connect medicinal product, active substance, ATC code, route-specific DDD, package quantity and study denominator before calculating a rate.
Audit one ATC/DDD conversion
Worked example: The study uses pharmacy dispensing records, not wholesaler sales. Preserve the index year, code level, route, strength, quantity, DDD value, number of DDDs per package and population-time denominator.
Keep a technical unit separate from a patient dose
The DDD is an assumed average adult maintenance dose for a main indication. It is a measurement unit, not necessarily the recommended or prescribed daily dose for an individual.
Respect the development boundary
Different sources capture different stages of medicine use. EMMA was registered on 27 October 2026 and remains under development. The current WHO ATC/DDD methodology and 2026 index are the factual floor.
Practical reader check
- Point to the exact source or method sentence supporting the claim.
- Name the person, setting, date, input and decision rule that could change its meaning.
- Label the remaining uncertainty reported, inferred, contested or unknown.
Student, parent and career transfer
Make one evidence card for “State the Drug-Use Question and Data Source”: source location, plain-language meaning, limit and next question. A parent or teacher can ask for one everyday explanation and one specialist explanation; both must preserve the same conditions. This habit supports pharmacy, pharmacoepidemiology, public health, health services research, medicines policy, biostatistics, data engineering and scientific writing without promising a grade, admission, funding decision or job.
CHAPTER 2 OF 16
2. Name the ATC/DDD Index and Guidelines Version
Why this move matters
Report the calendar release, access date and whether historical data were recoded to one version.
Did You Know? The index is updated annually.
Translate packages into a comparable measurement trail
Report the calendar release, access date and whether historical data were recoded to one version. Connect medicinal product, active substance, ATC code, route-specific DDD, package quantity and study denominator before calculating a rate.
Audit one ATC/DDD conversion
Worked example: All years are mapped to the 2026 index, with a table of changed codes. Preserve the index year, code level, route, strength, quantity, DDD value, number of DDDs per package and population-time denominator.
Keep a technical unit separate from a patient dose
The DDD is an assumed average adult maintenance dose for a main indication. It is a measurement unit, not necessarily the recommended or prescribed daily dose for an individual.
Respect the development boundary
Recoding can improve consistency while obscuring historical practice. EMMA was registered on 27 October 2026 and remains under development. The current WHO ATC/DDD methodology and 2026 index are the factual floor.
Practical reader check
- Point to the exact source or method sentence supporting the claim.
- Name the person, setting, date, input and decision rule that could change its meaning.
- Label the remaining uncertainty reported, inferred, contested or unknown.
Student, parent and career transfer
Make one evidence card for “Name the ATC/DDD Index and Guidelines Version”: source location, plain-language meaning, limit and next question. A parent or teacher can ask for one everyday explanation and one specialist explanation; both must preserve the same conditions. This habit supports pharmacy, pharmacoepidemiology, public health, health services research, medicines policy, biostatistics, data engineering and scientific writing without promising a grade, admission, funding decision or job.
CHAPTER 3 OF 16
3. Report the ATC Level and Selection Rules
Why this move matters
State whether analysis uses anatomical, therapeutic, pharmacological, chemical subgroup or substance level and how combination products are handled.
Did You Know? ATC has five hierarchical levels.
Translate packages into a comparable measurement trail
State whether analysis uses anatomical, therapeutic, pharmacological, chemical subgroup or substance level and how combination products are handled. Connect medicinal product, active substance, ATC code, route-specific DDD, package quantity and study denominator before calculating a rate.
Audit one ATC/DDD conversion
Worked example: The primary analysis uses fifth-level substance codes and groups results at level three. Preserve the index year, code level, route, strength, quantity, DDD value, number of DDDs per package and population-time denominator.
Keep a technical unit separate from a patient dose
The DDD is an assumed average adult maintenance dose for a main indication. It is a measurement unit, not necessarily the recommended or prescribed daily dose for an individual.
Respect the development boundary
Aggregation can hide substitution within a class. EMMA was registered on 27 October 2026 and remains under development. The current WHO ATC/DDD methodology and 2026 index are the factual floor.
Practical reader check
- Point to the exact source or method sentence supporting the claim.
- Name the person, setting, date, input and decision rule that could change its meaning.
- Label the remaining uncertainty reported, inferred, contested or unknown.
Student, parent and career transfer
Make one evidence card for “Report the ATC Level and Selection Rules”: source location, plain-language meaning, limit and next question. A parent or teacher can ask for one everyday explanation and one specialist explanation; both must preserve the same conditions. This habit supports pharmacy, pharmacoepidemiology, public health, health services research, medicines policy, biostatistics, data engineering and scientific writing without promising a grade, admission, funding decision or job.
CHAPTER 4 OF 16
4. Preserve Route of Administration
Why this move matters
Report oral, parenteral or other routes because DDD values may differ by route.
Did You Know? One DDD is assigned per ATC code and route where applicable.
Translate packages into a comparable measurement trail
Report oral, parenteral or other routes because DDD values may differ by route. Connect medicinal product, active substance, ATC code, route-specific DDD, package quantity and study denominator before calculating a rate.
Audit one ATC/DDD conversion
Worked example: Oral and injectable forms are analysed separately. Preserve the index year, code level, route, strength, quantity, DDD value, number of DDDs per package and population-time denominator.
Keep a technical unit separate from a patient dose
The DDD is an assumed average adult maintenance dose for a main indication. It is a measurement unit, not necessarily the recommended or prescribed daily dose for an individual.
Respect the development boundary
Route fields may be missing in claims data. EMMA was registered on 27 October 2026 and remains under development. The current WHO ATC/DDD methodology and 2026 index are the factual floor.
Practical reader check
- Point to the exact source or method sentence supporting the claim.
- Name the person, setting, date, input and decision rule that could change its meaning.
- Label the remaining uncertainty reported, inferred, contested or unknown.
Student, parent and career transfer
Make one evidence card for “Preserve Route of Administration”: source location, plain-language meaning, limit and next question. A parent or teacher can ask for one everyday explanation and one specialist explanation; both must preserve the same conditions. This habit supports pharmacy, pharmacoepidemiology, public health, health services research, medicines policy, biostatistics, data engineering and scientific writing without promising a grade, admission, funding decision or job.
CHAPTER 5 OF 16
5. Link Medicinal Products to Active Substances
Why this move matters
Describe product dictionary, identifiers, ingredient mapping, national codes, combination rules and quality checks.
Did You Know? Product linkage is a critical implementation step.
Translate packages into a comparable measurement trail
Describe product dictionary, identifiers, ingredient mapping, national codes, combination rules and quality checks. Connect medicinal product, active substance, ATC code, route-specific DDD, package quantity and study denominator before calculating a rate.
Audit one ATC/DDD conversion
Worked example: Each package code maps to active substance, strength and route before ATC assignment. Preserve the index year, code level, route, strength, quantity, DDD value, number of DDDs per package and population-time denominator.
Keep a technical unit separate from a patient dose
The DDD is an assumed average adult maintenance dose for a main indication. It is a measurement unit, not necessarily the recommended or prescribed daily dose for an individual.
Respect the development boundary
Local package dictionaries can contain errors or lag updates. EMMA was registered on 27 October 2026 and remains under development. The current WHO ATC/DDD methodology and 2026 index are the factual floor.
Practical reader check
- Point to the exact source or method sentence supporting the claim.
- Name the person, setting, date, input and decision rule that could change its meaning.
- Label the remaining uncertainty reported, inferred, contested or unknown.
Student, parent and career transfer
Make one evidence card for “Link Medicinal Products to Active Substances”: source location, plain-language meaning, limit and next question. A parent or teacher can ask for one everyday explanation and one specialist explanation; both must preserve the same conditions. This habit supports pharmacy, pharmacoepidemiology, public health, health services research, medicines policy, biostatistics, data engineering and scientific writing without promising a grade, admission, funding decision or job.
CHAPTER 6 OF 16
6. Report Strength, Quantity and Package Content
Why this move matters
Show units, concentration, number of dosage forms, pack size and conversions.
Did You Know? Package arithmetic precedes DDD arithmetic.
Translate packages into a comparable measurement trail
Show units, concentration, number of dosage forms, pack size and conversions. Connect medicinal product, active substance, ATC code, route-specific DDD, package quantity and study denominator before calculating a rate.
Audit one ATC/DDD conversion
Worked example: A box of 30 tablets at 10 mg is distinguished from 60 tablets at 5 mg. Preserve the index year, code level, route, strength, quantity, DDD value, number of DDDs per package and population-time denominator.
Keep a technical unit separate from a patient dose
The DDD is an assumed average adult maintenance dose for a main indication. It is a measurement unit, not necessarily the recommended or prescribed daily dose for an individual.
Respect the development boundary
Unit errors can multiply silently across large datasets. EMMA was registered on 27 October 2026 and remains under development. The current WHO ATC/DDD methodology and 2026 index are the factual floor.
Practical reader check
- Point to the exact source or method sentence supporting the claim.
- Name the person, setting, date, input and decision rule that could change its meaning.
- Label the remaining uncertainty reported, inferred, contested or unknown.
Student, parent and career transfer
Make one evidence card for “Report Strength, Quantity and Package Content”: source location, plain-language meaning, limit and next question. A parent or teacher can ask for one everyday explanation and one specialist explanation; both must preserve the same conditions. This habit supports pharmacy, pharmacoepidemiology, public health, health services research, medicines policy, biostatistics, data engineering and scientific writing without promising a grade, admission, funding decision or job.
CHAPTER 7 OF 16
7. State the Official or Local DDD Value
Why this move matters
Give DDD amount, unit, route, source and whether an unofficial or provisional local DDD was used.
Did You Know? Not every ATC-coded medicine has an official DDD.
Translate packages into a comparable measurement trail
Give DDD amount, unit, route, source and whether an unofficial or provisional local DDD was used. Connect medicinal product, active substance, ATC code, route-specific DDD, package quantity and study denominator before calculating a rate.
Audit one ATC/DDD conversion
Worked example: The report flags a locally assigned provisional value instead of presenting it as WHO official. Preserve the index year, code level, route, strength, quantity, DDD value, number of DDDs per package and population-time denominator.
Keep a technical unit separate from a patient dose
The DDD is an assumed average adult maintenance dose for a main indication. It is a measurement unit, not necessarily the recommended or prescribed daily dose for an individual.
Respect the development boundary
Local values reduce international comparability. EMMA was registered on 27 October 2026 and remains under development. The current WHO ATC/DDD methodology and 2026 index are the factual floor.
Practical reader check
- Point to the exact source or method sentence supporting the claim.
- Name the person, setting, date, input and decision rule that could change its meaning.
- Label the remaining uncertainty reported, inferred, contested or unknown.
Student, parent and career transfer
Make one evidence card for “State the Official or Local DDD Value”: source location, plain-language meaning, limit and next question. A parent or teacher can ask for one everyday explanation and one specialist explanation; both must preserve the same conditions. This habit supports pharmacy, pharmacoepidemiology, public health, health services research, medicines policy, biostatistics, data engineering and scientific writing without promising a grade, admission, funding decision or job.
CHAPTER 8 OF 16
8. Calculate DDDs per Package Transparently
Why this move matters
Provide the formula and worked example linking package active amount to the route-specific DDD.
Did You Know? A number of DDDs per package is a derived measure.
Translate packages into a comparable measurement trail
Provide the formula and worked example linking package active amount to the route-specific DDD. Connect medicinal product, active substance, ATC code, route-specific DDD, package quantity and study denominator before calculating a rate.
Audit one ATC/DDD conversion
Worked example: Total milligrams in a package are divided by the official oral DDD. Preserve the index year, code level, route, strength, quantity, DDD value, number of DDDs per package and population-time denominator.
Keep a technical unit separate from a patient dose
The DDD is an assumed average adult maintenance dose for a main indication. It is a measurement unit, not necessarily the recommended or prescribed daily dose for an individual.
Respect the development boundary
Combination products may need special rules. EMMA was registered on 27 October 2026 and remains under development. The current WHO ATC/DDD methodology and 2026 index are the factual floor.
Practical reader check
- Point to the exact source or method sentence supporting the claim.
- Name the person, setting, date, input and decision rule that could change its meaning.
- Label the remaining uncertainty reported, inferred, contested or unknown.
Student, parent and career transfer
Make one evidence card for “Calculate DDDs per Package Transparently”: source location, plain-language meaning, limit and next question. A parent or teacher can ask for one everyday explanation and one specialist explanation; both must preserve the same conditions. This habit supports pharmacy, pharmacoepidemiology, public health, health services research, medicines policy, biostatistics, data engineering and scientific writing without promising a grade, admission, funding decision or job.
CHAPTER 9 OF 16
9. Define Population and Time Denominators
Why this move matters
State inhabitants, insured persons, bed-days, patient-days or another denominator and the observation interval.
Did You Know? A rate is inseparable from its denominator.
Translate packages into a comparable measurement trail
State inhabitants, insured persons, bed-days, patient-days or another denominator and the observation interval. Connect medicinal product, active substance, ATC code, route-specific DDD, package quantity and study denominator before calculating a rate.
Audit one ATC/DDD conversion
Worked example: Rates are reported as DDDs per 1,000 inhabitants per day with population source and year. Preserve the index year, code level, route, strength, quantity, DDD value, number of DDDs per package and population-time denominator.
Keep a technical unit separate from a patient dose
The DDD is an assumed average adult maintenance dose for a main indication. It is a measurement unit, not necessarily the recommended or prescribed daily dose for an individual.
Respect the development boundary
Administrative coverage may not equal the resident population. EMMA was registered on 27 October 2026 and remains under development. The current WHO ATC/DDD methodology and 2026 index are the factual floor.
Practical reader check
- Point to the exact source or method sentence supporting the claim.
- Name the person, setting, date, input and decision rule that could change its meaning.
- Label the remaining uncertainty reported, inferred, contested or unknown.
Student, parent and career transfer
Make one evidence card for “Define Population and Time Denominators”: source location, plain-language meaning, limit and next question. A parent or teacher can ask for one everyday explanation and one specialist explanation; both must preserve the same conditions. This habit supports pharmacy, pharmacoepidemiology, public health, health services research, medicines policy, biostatistics, data engineering and scientific writing without promising a grade, admission, funding decision or job.
CHAPTER 10 OF 16
10. Describe Inclusion, Exclusion and Missing Products
Why this move matters
Report formularies, settings, over-the-counter use, hospital supply, missing package fields and medicines without DDDs.
Did You Know? Coverage boundaries affect every comparison.
Translate packages into a comparable measurement trail
Report formularies, settings, over-the-counter use, hospital supply, missing package fields and medicines without DDDs. Connect medicinal product, active substance, ATC code, route-specific DDD, package quantity and study denominator before calculating a rate.
Audit one ATC/DDD conversion
Worked example: Hospital-only products are excluded and the consequence is discussed. Preserve the index year, code level, route, strength, quantity, DDD value, number of DDDs per package and population-time denominator.
Keep a technical unit separate from a patient dose
The DDD is an assumed average adult maintenance dose for a main indication. It is a measurement unit, not necessarily the recommended or prescribed daily dose for an individual.
Respect the development boundary
Missing categories may differ by region. EMMA was registered on 27 October 2026 and remains under development. The current WHO ATC/DDD methodology and 2026 index are the factual floor.
Practical reader check
- Point to the exact source or method sentence supporting the claim.
- Name the person, setting, date, input and decision rule that could change its meaning.
- Label the remaining uncertainty reported, inferred, contested or unknown.
Student, parent and career transfer
Make one evidence card for “Describe Inclusion, Exclusion and Missing Products”: source location, plain-language meaning, limit and next question. A parent or teacher can ask for one everyday explanation and one specialist explanation; both must preserve the same conditions. This habit supports pharmacy, pharmacoepidemiology, public health, health services research, medicines policy, biostatistics, data engineering and scientific writing without promising a grade, admission, funding decision or job.
CHAPTER 11 OF 16
11. Track Code and DDD Changes Over Time
Why this move matters
Identify annual alterations, mergers, splits and revised DDDs and explain harmonisation.
Did You Know? Version history is part of longitudinal validity.
Translate packages into a comparable measurement trail
Identify annual alterations, mergers, splits and revised DDDs and explain harmonisation. Connect medicinal product, active substance, ATC code, route-specific DDD, package quantity and study denominator before calculating a rate.
Audit one ATC/DDD conversion
Worked example: A sensitivity analysis recalculates trends under contemporaneous and fixed 2026 values. Preserve the index year, code level, route, strength, quantity, DDD value, number of DDDs per package and population-time denominator.
Keep a technical unit separate from a patient dose
The DDD is an assumed average adult maintenance dose for a main indication. It is a measurement unit, not necessarily the recommended or prescribed daily dose for an individual.
Respect the development boundary
A trend can reflect classification change rather than use. EMMA was registered on 27 October 2026 and remains under development. The current WHO ATC/DDD methodology and 2026 index are the factual floor.
Practical reader check
- Point to the exact source or method sentence supporting the claim.
- Name the person, setting, date, input and decision rule that could change its meaning.
- Label the remaining uncertainty reported, inferred, contested or unknown.
Student, parent and career transfer
Make one evidence card for “Track Code and DDD Changes Over Time”: source location, plain-language meaning, limit and next question. A parent or teacher can ask for one everyday explanation and one specialist explanation; both must preserve the same conditions. This habit supports pharmacy, pharmacoepidemiology, public health, health services research, medicines policy, biostatistics, data engineering and scientific writing without promising a grade, admission, funding decision or job.
CHAPTER 12 OF 16
12. Validate Mappings and Calculations
Why this move matters
Report automated and manual checks, sampled package review, duplicate handling and reconciliation to source totals.
Did You Know? Validation should test the conversion chain.
Translate packages into a comparable measurement trail
Report automated and manual checks, sampled package review, duplicate handling and reconciliation to source totals. Connect medicinal product, active substance, ATC code, route-specific DDD, package quantity and study denominator before calculating a rate.
Audit one ATC/DDD conversion
Worked example: A pharmacist reviews high-volume and unmatched products. Preserve the index year, code level, route, strength, quantity, DDD value, number of DDDs per package and population-time denominator.
Keep a technical unit separate from a patient dose
The DDD is an assumed average adult maintenance dose for a main indication. It is a measurement unit, not necessarily the recommended or prescribed daily dose for an individual.
Respect the development boundary
A clean total can still contain systematic misclassification. EMMA was registered on 27 October 2026 and remains under development. The current WHO ATC/DDD methodology and 2026 index are the factual floor.
Practical reader check
- Point to the exact source or method sentence supporting the claim.
- Name the person, setting, date, input and decision rule that could change its meaning.
- Label the remaining uncertainty reported, inferred, contested or unknown.
Student, parent and career transfer
Make one evidence card for “Validate Mappings and Calculations”: source location, plain-language meaning, limit and next question. A parent or teacher can ask for one everyday explanation and one specialist explanation; both must preserve the same conditions. This habit supports pharmacy, pharmacoepidemiology, public health, health services research, medicines policy, biostatistics, data engineering and scientific writing without promising a grade, admission, funding decision or job.
CHAPTER 13 OF 16
13. Separate DDD From Prescribed Daily Dose
Why this move matters
Explain that DDD is a technical adult average for a main indication and compare with PDD only when appropriate data exist.
Did You Know? WHO explicitly distinguishes DDD and PDD.
Translate packages into a comparable measurement trail
Explain that DDD is a technical adult average for a main indication and compare with PDD only when appropriate data exist. Connect medicinal product, active substance, ATC code, route-specific DDD, package quantity and study denominator before calculating a rate.
Audit one ATC/DDD conversion
Worked example: The study does not infer patient adherence from DDD counts. Preserve the index year, code level, route, strength, quantity, DDD value, number of DDDs per package and population-time denominator.
Keep a technical unit separate from a patient dose
The DDD is an assumed average adult maintenance dose for a main indication. It is a measurement unit, not necessarily the recommended or prescribed daily dose for an individual.
Respect the development boundary
Patient doses vary by indication, age, severity and practice. EMMA was registered on 27 October 2026 and remains under development. The current WHO ATC/DDD methodology and 2026 index are the factual floor.
Practical reader check
- Point to the exact source or method sentence supporting the claim.
- Name the person, setting, date, input and decision rule that could change its meaning.
- Label the remaining uncertainty reported, inferred, contested or unknown.
Student, parent and career transfer
Make one evidence card for “Separate DDD From Prescribed Daily Dose”: source location, plain-language meaning, limit and next question. A parent or teacher can ask for one everyday explanation and one specialist explanation; both must preserve the same conditions. This habit supports pharmacy, pharmacoepidemiology, public health, health services research, medicines policy, biostatistics, data engineering and scientific writing without promising a grade, admission, funding decision or job.
CHAPTER 14 OF 16
14. Handle Paediatric and Special Populations Carefully
Why this move matters
Report why adult-based DDDs may misrepresent children or other groups and use alternative measures where needed.
Did You Know? WHO cautions that paediatric drug-utilisation questions cannot be solved by DDD alone.
Translate packages into a comparable measurement trail
Report why adult-based DDDs may misrepresent children or other groups and use alternative measures where needed. Connect medicinal product, active substance, ATC code, route-specific DDD, package quantity and study denominator before calculating a rate.
Audit one ATC/DDD conversion
Worked example: Paediatric use is reported through prescriptions and prescribed doses rather than crude adult DDD prevalence. Preserve the index year, code level, route, strength, quantity, DDD value, number of DDDs per package and population-time denominator.
Keep a technical unit separate from a patient dose
The DDD is an assumed average adult maintenance dose for a main indication. It is a measurement unit, not necessarily the recommended or prescribed daily dose for an individual.
Respect the development boundary
Some subgroup data may be unavailable. EMMA was registered on 27 October 2026 and remains under development. The current WHO ATC/DDD methodology and 2026 index are the factual floor.
Practical reader check
- Point to the exact source or method sentence supporting the claim.
- Name the person, setting, date, input and decision rule that could change its meaning.
- Label the remaining uncertainty reported, inferred, contested or unknown.
Student, parent and career transfer
Make one evidence card for “Handle Paediatric and Special Populations Carefully”: source location, plain-language meaning, limit and next question. A parent or teacher can ask for one everyday explanation and one specialist explanation; both must preserve the same conditions. This habit supports pharmacy, pharmacoepidemiology, public health, health services research, medicines policy, biostatistics, data engineering and scientific writing without promising a grade, admission, funding decision or job.
CHAPTER 15 OF 16
15. Report Comparisons and Sensitivity Analyses
Why this move matters
Show confidence or uncertainty, alternative denominators, versions, inclusion rules and the effect of local DDDs.
Did You Know? Sensitivity analyses reveal dependence on measurement choices.
Translate packages into a comparable measurement trail
Show confidence or uncertainty, alternative denominators, versions, inclusion rules and the effect of local DDDs. Connect medicinal product, active substance, ATC code, route-specific DDD, package quantity and study denominator before calculating a rate.
Audit one ATC/DDD conversion
Worked example: Regional rankings are tested under population and insured-person denominators. Preserve the index year, code level, route, strength, quantity, DDD value, number of DDDs per package and population-time denominator.
Keep a technical unit separate from a patient dose
The DDD is an assumed average adult maintenance dose for a main indication. It is a measurement unit, not necessarily the recommended or prescribed daily dose for an individual.
Respect the development boundary
A stable ranking does not explain causes. EMMA was registered on 27 October 2026 and remains under development. The current WHO ATC/DDD methodology and 2026 index are the factual floor.
Practical reader check
- Point to the exact source or method sentence supporting the claim.
- Name the person, setting, date, input and decision rule that could change its meaning.
- Label the remaining uncertainty reported, inferred, contested or unknown.
Student, parent and career transfer
Make one evidence card for “Report Comparisons and Sensitivity Analyses”: source location, plain-language meaning, limit and next question. A parent or teacher can ask for one everyday explanation and one specialist explanation; both must preserve the same conditions. This habit supports pharmacy, pharmacoepidemiology, public health, health services research, medicines policy, biostatistics, data engineering and scientific writing without promising a grade, admission, funding decision or job.
CHAPTER 16 OF 16
16. Conclude With Bounded Medicines-Use Claims
Why this move matters
State what consumption proxy supports, what it cannot show about indication, adherence or appropriateness, and what linked data are needed next.
Did You Know? Careful English keeps a technical measure in its proper role.
Translate packages into a comparable measurement trail
State what consumption proxy supports, what it cannot show about indication, adherence or appropriateness, and what linked data are needed next. Connect medicinal product, active substance, ATC code, route-specific DDD, package quantity and study denominator before calculating a rate.
Audit one ATC/DDD conversion
Worked example: Higher DDD rates are described as greater measured consumption, not better or worse prescribing. Preserve the index year, code level, route, strength, quantity, DDD value, number of DDDs per package and population-time denominator.
Keep a technical unit separate from a patient dose
The DDD is an assumed average adult maintenance dose for a main indication. It is a measurement unit, not necessarily the recommended or prescribed daily dose for an individual.
Respect the development boundary
Ecological comparisons can invite causal overreach. EMMA was registered on 27 October 2026 and remains under development. The current WHO ATC/DDD methodology and 2026 index are the factual floor.
Practical reader check
- Point to the exact source or method sentence supporting the claim.
- Name the person, setting, date, input and decision rule that could change its meaning.
- Label the remaining uncertainty reported, inferred, contested or unknown.
Student, parent and career transfer
Make one evidence card for “Conclude With Bounded Medicines-Use Claims”: source location, plain-language meaning, limit and next question. A parent or teacher can ask for one everyday explanation and one specialist explanation; both must preserve the same conditions. This habit supports pharmacy, pharmacoepidemiology, public health, health services research, medicines policy, biostatistics, data engineering and scientific writing without promising a grade, admission, funding decision or job.
PRACTICE LAB
Build a EMMA ATC/DDD drug-use reporting decision trail
Student route
- Choose one original report inside this guide’s scope.
- Copy its objective and underline actor, action, context, evidence and intended decision.
- Draw the specific reasoning chain used in this article.
- Mark each step reported, inferred, contested or unknown.
- Rewrite the conclusion so it preserves the narrowest important limitation.
Parent or teacher route
Ask the learner to explain how English helps us make an atc/ddd drug-use study traceable from medicinal product packages to comparable population measures twice: once to a classmate and once to a method specialist. Praise a precise correction and a well-stated unknown; both show disciplined attention to evidence.
Early-career route
Create a one-page EMMA ATC/DDD drug-use reporting audit with source link, date checked, scope, method logic, decisive wording, contrary evidence, limit and next action. A colleague should be able to continue without guessing.
Decision rule
If a shorter explanation removes the condition that made the original claim true, it is not clearer yet. Restore the condition.
Continue with eduKate’s guides to reading course and career information and giving useful feedback in group projects.
USEFUL NEXT READING
Connect this guide to the next useful reading
Read the RECORD-PE pharmacoepidemiology guide for a related but different reader job. Return here when the question is specifically how to make an atc/ddd drug-use study traceable from medicinal product packages to comparable population measures. This keeps each reading route clear and useful.
For English practice across research, school and career communication, visit the Singapore English Tuition Centre learning site.
FREQUENTLY ASKED QUESTIONS
Questions students and parents often ask
Is EMMA final?
No. EQUATOR lists it as under development after registration on 27 October 2026.
What is a DDD?
The assumed average maintenance dose per day for a drug used for its main indication in adults.
Is a DDD the dose a patient should take?
No. It is a technical measurement unit and may differ from prescribed or recommended doses.
Why report the index year?
ATC codes and DDD assignments can change annually.
Do all medicines have DDDs?
No. WHO does not assign DDDs to every ATC-coded medicine.
Can DDD rates measure adherence?
Not by themselves. They are aggregate consumption proxies and need other data for patient-level adherence.
PRIMARY SOURCES
Read the original EMMA ATC/DDD drug-use reporting guidance
Facts were checked against original publications and official records on 6 November 2026. Follow the live source for later corrections, completed updates or companion material.
- EMMA development record, EQUATOR Network
- WHO ATC/DDD methodology
- WHO Defined Daily Dose guidance
- WHO Collaborating Centre 2026 ATC/DDD Index
- WHO Collaborating Centre 2026 Guidelines
A cheerful final note
Precise English helps us make an atc/ddd drug-use study traceable from medicinal product packages to comparable population measures more generous, not less. People can see how their evidence and values entered the work, where disagreement remains and what a responsible next step looks like.