Which measures are registered together

A study can register main outcomes in several classes. For each pair of classes, this page counts the studies that registered a main outcome in both. The unit is the study, not the entry.

Registry data from ClinicalTrials.gov, an online database; the U.S. National Library of Medicine maintains its website. This lab is independent of the registry; the grouping and counts are the lab's work, not the registry's.

These are counts of what trial teams registered, not trial results. What this does not say

Not paired, by the research tools' rule: Other and No measure named.

No study in this dated copy: Intestinal current measurement.

About this dated copy

Registry data processed: October 9, 2026
Dated copy: d164700bb17d
Studies: 1072
Main-outcome entries: 2052
Sorted by rule: 1839 entries, lexicon 0.3.2-draft
Sorted by a model, checked against an exact quote from the record: 70 entries
Named no measure: 32 entries
Not yet in a class: 111 entries
Synthetic marker: none found (this does not prove where the data came from)
Hand check of a sample: not recorded in this data file

Registry records change; the live record on ClinicalTrials.gov is current, this page is not. Open ClinicalTrials.gov (opens another site).

Studies that registered both

Counts of studies that registered a main outcome in both classes. This shows what trials registered together, not which measures agree, replace or predict each other. Each pair is shown once, below the diagonal. The diagonal gives each class's own number of studies.

Sorted by the number of studies, then by the lexicon's order. A pair registered often is not a better pair.

Pairs with at least one study: 102
Pair	Studies
FEV1 and Safety and tolerability	studies that registered both: 32
FEV1 and Other spirometry	studies that registered both: 24
Safety and tolerability and Pharmacokinetics	studies that registered both: 22
Other spirometry and Safety and tolerability	studies that registered both: 14
Oxygen and carbon dioxide levels and Safety and tolerability	studies that registered both: 13
FEV1 and Exercise capacity	studies that registered both: 8
FEV1 and CFQ-R	studies that registered both: 7
Other spirometry and Oxygen and carbon dioxide levels	studies that registered both: 6
Pulmonary exacerbations and Safety and tolerability	studies that registered both: 6
Nutrition and growth and Inflammation markers	studies that registered both: 6
Exercise capacity and Muscle strength and endurance	studies that registered both: 6
FEV1 and Oxygen and carbon dioxide levels	studies that registered both: 5
FEV1 and Pulmonary exacerbations	studies that registered both: 5
FEV1 and Nutrition and growth	studies that registered both: 5
Other spirometry and CFQ-R	studies that registered both: 5
FEV1 and Airway resistance, compliance and lung volumes	studies that registered both: 4
FEV1 and Sweat chloride	studies that registered both: 4
FEV1 and Sputum amount and properties	studies that registered both: 4
FEV1 and Inflammation markers	studies that registered both: 4
FEV1 and Muscle strength and endurance	studies that registered both: 4

(82 more pairs)

The other pairs, in the same order
Pair	Studies
Other spirometry and Sputum amount and properties	studies that registered both: 4
Other spirometry and Exercise capacity	studies that registered both: 4
Nutrition and growth and Glucose and cystic fibrosis-related diabetes	studies that registered both: 4
Nutrition and growth and Safety and tolerability	studies that registered both: 4
Glucose and cystic fibrosis-related diabetes and Safety and tolerability	studies that registered both: 4
Inflammation markers and Safety and tolerability	studies that registered both: 4
FEV1 and Lung clearance index	studies that registered both: 3
Other spirometry and Airway resistance, compliance and lung volumes	studies that registered both: 3
Other spirometry and Pulmonary exacerbations	studies that registered both: 3
Other spirometry and Muscle strength and endurance	studies that registered both: 3
Lung clearance index and Safety and tolerability	studies that registered both: 3
Airway resistance, compliance and lung volumes and Imaging	studies that registered both: 3
Sweat chloride and Safety and tolerability	studies that registered both: 3
CFQ-R and Inflammation markers	studies that registered both: 3
FEV1 and Pharmacokinetics	studies that registered both: 2
Other spirometry and Nutrition and growth	studies that registered both: 2
Other spirometry and Inflammation markers	studies that registered both: 2
Lung clearance index and Inflammation markers	studies that registered both: 2
Pulmonary exacerbations and Inflammation markers	studies that registered both: 2
Nutrition and growth and CFQ-R	studies that registered both: 2
Bone mineral density and Imaging	studies that registered both: 2
CFQ-R and Exercise capacity	studies that registered both: 2
Inflammation markers and Gene expression and methylation	studies that registered both: 2
FEV1 and Glucose and cystic fibrosis-related diabetes	studies that registered both: 1
FEV1 and Imaging	studies that registered both: 1
Other spirometry and Lung clearance index	studies that registered both: 1
Other spirometry and Sinus and upper airway	studies that registered both: 1
Other spirometry and Imaging	studies that registered both: 1
Other spirometry and Pharmacokinetics	studies that registered both: 1
Lung clearance index and Airway resistance, compliance and lung volumes	studies that registered both: 1
Lung clearance index and Pulmonary exacerbations	studies that registered both: 1
Lung clearance index and Nutrition and growth	studies that registered both: 1
Lung clearance index and CFQ-R	studies that registered both: 1
Lung clearance index and Imaging	studies that registered both: 1
Lung clearance index and Sputum amount and properties	studies that registered both: 1
Airway resistance, compliance and lung volumes and Oxygen and carbon dioxide levels	studies that registered both: 1
Airway resistance, compliance and lung volumes and Pulmonary exacerbations	studies that registered both: 1
Airway resistance, compliance and lung volumes and CFQ-R	studies that registered both: 1
Airway resistance, compliance and lung volumes and Sputum amount and properties	studies that registered both: 1
Oxygen and carbon dioxide levels and Nutrition and growth	studies that registered both: 1
Oxygen and carbon dioxide levels and Bone mineral density	studies that registered both: 1
Oxygen and carbon dioxide levels and Glucose and cystic fibrosis-related diabetes	studies that registered both: 1
Oxygen and carbon dioxide levels and Imaging	studies that registered both: 1
Oxygen and carbon dioxide levels and Inflammation markers	studies that registered both: 1
Oxygen and carbon dioxide levels and Gene expression and methylation	studies that registered both: 1
Oxygen and carbon dioxide levels and Exercise capacity	studies that registered both: 1
Sweat chloride and Other CFTR biomarker	studies that registered both: 1
Sweat chloride and Pharmacokinetics	studies that registered both: 1
Pulmonary exacerbations and Nutrition and growth	studies that registered both: 1
Pulmonary exacerbations and CFQ-R	studies that registered both: 1
Pulmonary exacerbations and Sputum amount and properties	studies that registered both: 1
Nutrition and growth and Bone mineral density	studies that registered both: 1
Nutrition and growth and Sinus and upper airway	studies that registered both: 1
Nutrition and growth and Gene expression and methylation	studies that registered both: 1
Nutrition and growth and Oxidative stress markers	studies that registered both: 1
Nutrition and growth and Pharmacokinetics	studies that registered both: 1
Nutrition and growth and Exercise capacity	studies that registered both: 1
Nutrition and growth and Muscle strength and endurance	studies that registered both: 1
Bone mineral density and Glucose and cystic fibrosis-related diabetes	studies that registered both: 1
Bone mineral density and Inflammation markers	studies that registered both: 1
Bone mineral density and Gene expression and methylation	studies that registered both: 1
Bone mineral density and Safety and tolerability	studies that registered both: 1
Glucose and cystic fibrosis-related diabetes and Imaging	studies that registered both: 1
Glucose and cystic fibrosis-related diabetes and Inflammation markers	studies that registered both: 1
Glucose and cystic fibrosis-related diabetes and Gene expression and methylation	studies that registered both: 1
Glucose and cystic fibrosis-related diabetes and Oxidative stress markers	studies that registered both: 1
Glucose and cystic fibrosis-related diabetes and Pharmacokinetics	studies that registered both: 1
Sinus and upper airway and CFQ-R	studies that registered both: 1
Sinus and upper airway and Imaging	studies that registered both: 1
CFQ-R and Sputum amount and properties	studies that registered both: 1
CFQ-R and Safety and tolerability	studies that registered both: 1
CFQ-R and Muscle strength and endurance	studies that registered both: 1
Imaging and Sputum amount and properties	studies that registered both: 1
Imaging and Inflammation markers	studies that registered both: 1
Imaging and Exercise capacity	studies that registered both: 1
Sputum amount and properties and Inflammation markers	studies that registered both: 1
Sputum amount and properties and Exercise capacity	studies that registered both: 1
Sputum amount and properties and Muscle strength and endurance	studies that registered both: 1
Inflammation markers and Oxidative stress markers	studies that registered both: 1
Inflammation markers and Muscle strength and endurance	studies that registered both: 1
Gene expression and methylation and Safety and tolerability	studies that registered both: 1
Safety and tolerability and Exercise capacity	studies that registered both: 1

Every pair at once (table of all pairs)

Every pair at once: studies per pair of classes, 24 classes.

Scroll sideways to see all 24 columns.

Class	FEV1	Other spirometry	Lung clearance index	Airway resistance, compliance and lung volumes	Oxygen and carbon dioxide levels	Sweat chloride	Nasal potential difference	Other CFTR biomarker	Pulmonary exacerbations	Nutrition and growth	Bone mineral density	Glucose and cystic fibrosis-related diabetes	Sinus and upper airway	CFQ-R	Imaging	Mucociliary clearance	Sputum amount and properties	Inflammation markers	Gene expression and methylation	Oxidative stress markers	Safety and tolerability	Pharmacokinetics	Exercise capacity	Muscle strength and endurance
FEV1	studies naming FEV1: 164
Other spirometry	24	studies naming Other spirometry: 46
Lung clearance index	3	1	studies naming Lung clearance index: 26
Airway resistance, compliance and lung volumes	4	3	1	studies naming Airway resistance, compliance and lung volumes: 13
Oxygen and carbon dioxide levels	5	6	0	1	studies naming Oxygen and carbon dioxide levels: 22
Sweat chloride	4	0	0	0	0	studies naming Sweat chloride: 16
Nasal potential difference	0	0	0	0	0	0	studies naming Nasal potential difference: 16
Other CFTR biomarker	0	0	0	0	0	1	0	studies naming Other CFTR biomarker: 16
Pulmonary exacerbations	5	3	1	1	0	0	0	0	studies naming Pulmonary exacerbations: 40
Nutrition and growth	5	2	1	0	1	0	0	0	1	studies naming Nutrition and growth: 46
Bone mineral density	0	0	0	0	1	0	0	0	0	1	studies naming Bone mineral density: 8
Glucose and cystic fibrosis-related diabetes	1	0	0	0	1	0	0	0	0	4	1	studies naming Glucose and cystic fibrosis-related diabetes: 49
Sinus and upper airway	0	1	0	0	0	0	0	0	0	1	0	0	studies naming Sinus and upper airway: 9
CFQ-R	7	5	1	1	0	0	0	0	1	2	0	0	1	studies naming CFQ-R: 23
Imaging	1	1	1	3	1	0	0	0	0	0	2	1	1	0	studies naming Imaging: 41
Mucociliary clearance	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	studies naming Mucociliary clearance: 16
Sputum amount and properties	4	4	1	1	0	0	0	0	1	0	0	0	0	1	1	0	studies naming Sputum amount and properties: 21
Inflammation markers	4	2	2	0	1	0	0	0	2	6	1	1	0	3	1	0	1	studies naming Inflammation markers: 42
Gene expression and methylation	0	0	0	0	1	0	0	0	0	1	1	1	0	0	0	0	0	2	studies naming Gene expression and methylation: 7
Oxidative stress markers	0	0	0	0	0	0	0	0	0	1	0	1	0	0	0	0	0	1	0	studies naming Oxidative stress markers: 12
Safety and tolerability	32	14	3	0	13	3	0	0	6	4	1	4	0	1	0	0	0	4	1	0	studies naming Safety and tolerability: 220
Pharmacokinetics	2	1	0	0	0	1	0	0	0	1	0	1	0	0	0	0	0	0	0	0	22	studies naming Pharmacokinetics: 91
Exercise capacity	8	4	0	0	1	0	0	0	0	1	0	0	0	2	1	0	1	0	0	0	1	0	studies naming Exercise capacity: 49
Muscle strength and endurance	4	3	0	0	0	0	0	0	0	1	0	0	0	1	0	0	1	1	0	0	0	0	6	studies naming Muscle strength and endurance: 11

The pairs as CSV

Where the data come from, and what the lab changed

Source: ClinicalTrials.gov
Data processed by the registry: October 9, 2026 (as given: 2026-10-09T09:00:05; the registry gives no time zone)
Live record: Registry records change; the live record on ClinicalTrials.gov is current, this page is not.
License: The lab's licence covers its own tags, code and counts only; registry text and fields remain ClinicalTrials.gov data under its terms.
No warranty: ClinicalTrials.gov states that the U.S. Government makes no warranties, expressed or implied, about its data and assumes no liability for any party's use of them.
Sponsor responsibility: Study sponsors and investigators write and are responsible for their own records. The registry's Disclaimer says the U.S. government "does not review or approve the safety and science of all studies listed on this website" and that NLM staff only review study information for apparent errors, deficiencies or inconsistencies. See the registry's Disclaimer.
Disclaimer page: https://clinicaltrials.gov/about-site/disclaimer
Disclaimer last updated: 2023-08-03

The registry's terms page, the dated copy's date, every change the lab made, and keeping the data

Dated copy taken

October 11, 2026 (2026-10-11 03:59:17 UTC)

Registry terms

Terms and Conditions of ClinicalTrials.gov (last updated January 31, 2023)

Changes the lab made

Primary-outcome wording was classified into classes by the versioned rule lexicon 0.3.2-draft (sha256 f4bd1af4c664); a model-proposed class is counted only when its quote is an exact piece of the registry text.
Studies were left out by stated scope rules, with these counts: X1 554, X2 7, X3 0, X4 91, X5 48, X6 0 (explained in trial-atlas-data-dictionary.txt; X6 is a person's exclusion list).
Start dates without a recorded date type are counted as their own kind; no type is assumed.
No registry wording was clipped by these tools; any clipping on a published page must be added to this list.
Registry pages were re-saved as UTF-8 JSON after parsing; values and key order are kept, whitespace is not.
This page and its downloads show counts only: no registry wording, trial ids or sponsor names.
Start years are also grouped into five-year periods for narrow screens; the yearly counts are in the downloads.
Phase codes are written in plain words (PHASE1 as Phase 1, PHASE1/PHASE2 as Phase 1/2, EARLY_PHASE1 as Early phase 1); NA is shown as written, and a study with no phase is shown as None given.

Keeping the data

The registry's terms apply for as long as the data are kept, in any copy, file or page made from them.

Third party copyright

Some registry data may be subject to third-party copyright, and the data carry an international copyright outside the United States and its Territories or Possessions.

Keep current

The registry says it is updated daily and that data in any publication or distribution should be kept current at all times. This copy is dated and may be out of date; the live record is the current one.