Observational Study of Canadian Patients (6 Years or Older) Receiving Dupixent® for Moderate to Severe Atopic Dermatitis

EASI is a validated measure used to assess the severity and extent of AD. Four AD disease characteristics [erythema, thickness (induration, papulation, and edema), scratching (excoriation), and lichenification] will each be assessed for severity by the Investigator or designee on a scale of "0" (absent) through "3" (severe). In addition, the area of AD involvement will be assessed as a percentage of each body area assessed: head, trunk, upper limbs, and lower limbs, and converted to a score of 0 to 6. In each body region, the area is expressed as 0 (0%), 1 (1% to 9%), 2 (10% to 29%), 3 (30% to 49%), 4 (50% to 69%), 5 (70% to 89%), or 6 (90% to 100%). Total score is the sum of all subscores. EASI is a composite index with scores ranging from 0 to 72. Higher scores indicates worse condition. Data will be assessed to understand real-world effectiveness of Dupixent in a heterogeneic population of Canadian participants who initiate treatment for msAD using EASI score.

EASI is a validated measure used to assess the severity and extent of AD. Four AD disease characteristics [erythema, thickness (induration, papulation, and edema), scratching (excoriation), and lichenification] will each be assessed for severity by the Investigator or designee on a scale of "0" (absent) through "3" (severe). In addition, the area of AD involvement will be assessed as a percentage of each body area assessed: head, trunk, upper limbs, and lower limbs, and converted to a score of 0 to 6. In each body region, the area is expressed as 0 (0%), 1 (1% to 9%), 2 (10% to 29%), 3 (30% to 49%), 4 (50% to 69%), 5 (70% to 89%), or 6 (90% to 100%). Total score is the sum of all subscores. EASI is a composite index with scores ranging from 0 to 72. Higher scores indicates worse condition. Data will be assessed to understand real-world effectiveness of Dupixent in a heterogeneic population of Canadian participants who initiate treatment for msAD using EASI score.

EASI is a validated measure used to assess the severity and extent of AD. Four AD disease characteristics [erythema, thickness (induration, papulation, and edema), scratching (excoriation), and lichenification] will each be assessed for severity by the Investigator or designee on a scale of "0" (absent) through "3" (severe). In addition, the area of AD involvement will be assessed as a percentage of each body area assessed: head, trunk, upper limbs, and lower limbs, and converted to a score of 0 to 6. In each body region, the area is expressed as 0 (0%), 1 (1% to 9%), 2 (10% to 29%), 3 (30% to 49%), 4 (50% to 69%), 5 (70% to 89%), or 6 (90% to 100%). Total score is the sum of all subscores. EASI is a composite index with scores ranging from 0 to 72. Higher scores indicates worse condition. Data will be assessed to understand real-world effectiveness of Dupixent in a heterogeneic population of Canadian participants who initiate treatment for msAD using EASI score.

Four AD disease characteristics [erythema, thickness (induration, papulation, and edema), scratching (excoriation), and lichenification] will each be assessed for severity by the Investigator or designee on a scale of "0" (absent) through "3" (severe). In addition, the area of AD involvement will be assessed as a percentage of each body area assessed: head, trunk, upper limbs, and lower limbs, and converted to a score of 0 to 6. In each body region, the area is expressed as 0 (0%), 1 (1% to 9%), 2 (10% to 29%), 3 (30% to 49%), 4 (50% to 69%), 5 (70% to 89%), or 6 (90% to 100%). Total score is the sum of all subscores. EASI is a composite index with scoresEASI is a composite index with scores ranging from 0-72. Higher scores indicate worse conditions. Data will be assessed to understand (1) the real-world effectiveness of of Dupixent in a heterogeneic population and (2) to characterize disease burden and unmet need in Canadian participants who initiate treatment for msAD.

BSA affected by AD disease will be assessed for each major section of the body (head, neck, anterior trunk, back, upper limbs, lower limbs, and genitals). It will be reported as a percentage of all major body sections combined. Data will be assessed to understand (1) the real-world effectiveness of of Dupixent in a heterogeneic population and (2) to characterize disease burden and unmet need in Canadian participants who initiate treatment for msAD.

HADS is a 14-item scale, with 7 items relating to anxiety and 7 relating to depression. Each item on the questionnaire is scored from 0-3. The anxiety/depression score is the sum of the scores of the 7 related items; one can score between 0 and 21 for either anxiety or depression. The total score is the sum of the scores of the 14 items ranging from 0 (no symptoms) to 42 (severe symptoms), with higher scores indicating higher nxiety/depression complains. Data will be assessed to understand (1) the real-world effectiveness of of Dupixent in a heterogeneic population and (2) to characterize disease burden and unmet need in Canadian participants who initiate treatment for msAD.

Skin pain NRS is a simple assessment tool asking participants to rate their skin pain or soreness using a 0 (No pain or soreness) to 10 (worst possible pain or soreness) NRS. Data will be assessed to understand (1) the real-world effectiveness of of Dupixent in a heterogeneic population and (2) to characterize disease burden and unmet need in Canadian participants who initiate treatment for msAD.

Skin burning NRS is a simple assessment tool asking participants to rate the sensation of their skin feeling hot or burning sensation using a 0 (Not feeling hot at all) to 10 (feeling extremely hot) NRS. Data will be assessed to understand (1) the real-world effectiveness of of Dupixent in a heterogeneic population and (2) to characterize disease burden and unmet need in Canadian participants who initiate treatment for msAD.

The peak pruritus NRS is a simple assessment tool asking participants to rate the intensity of their pruritis (itch) using a 0 (no itch) to 10 (worst possible itch) NRS. Data will be assessed to understand (1) the real-world effectiveness of of Dupixent in a heterogeneic population and (2) to characterize disease burden and unmet need in Canadian participants who initiate treatment for msAD.

Data will be assessed to understand the real-world safety of Dupixent in a heterogeneic population of Canadian participants who initiate treatment for msAD

Data will be assessed to understand the real-world safety of Dupixent in a heterogeneic population of Canadian participants who initiate treatment for msAD

Data will be assessed to understand the real-world safety of Dupixent in a heterogeneic population of Canadian participants who initiate treatment for msAD

Data will be assessed to understand the real-world safety of Dupixent in a heterogeneic population of Canadian participants who initiate treatment for msAD

EASI is a validated measure used in clinical practice and clinical trials to assess the severity and extent. Four AD disease characteristics - erythema, thickness (induration, papulation, and edema), scratching (excoriation), and lichenification - will each be assessed for severity by the Investigator or designee on a scale of "0" (absent) through "3" (severe). In addition, the area of AD involvement will be assessed as a percentage of each body area assessed: head, trunk, upper limbs, and lower limbs, and converted to a score of 0 to 6. In each body region, the area is expressed as 0 (0%), 1 (1% to 9%), 2 (10% to 29%), 3 (30% to 49%), 4 (50% to 69%), 5 (70% to 89%), or 6 (90% to 100%). Total score is the sum of all subscores. EASI is a composite index with scores. Data will be assessed to characterize disease burden and unmet need in Canadian msAD participants who initiate treatment with Dupixent.

BSA affected by AD disease will be assessed for each major section of the body (head, neck, anterior trunk, back, upper limbs, lower limbs, and genitals). It will be reported as a percentage of all major body sections combined. Data will be assessed to characterize disease burden and unmet need in Canadian msAD participants who initiate treatment with Dupixent.

Data will be assessed to characterize disease burden and unmet need in Canadian msAD participants who initiate treatment with Dupixent. Data will be assessed to characterize disease burden and unmet need in Canadian msAD participants who initiate treatment with Dupixent.

Participants will be asked to report the severity of their sleep disturbance during the past 7 days using a 0 (sleep not disturbed at all) to 10 (sleep extremely disturbed) NRS. Data will be assessed to characterize disease burden and unmet need in Canadian msAD participants who initiate treatment with Dupixent.

The DLQI and CDLQI are a 10-item validated questionnaire to assess the impact of AD disease on quality of life (QoL) in adults and adolescents/pediatrics, respectively. The rating scale range from 0 (not at all) to 3 (very much) 10 items, which assess QoL over the past week. The total score is the sum of all 10-items ranging from 0 to 30; a high score is indicative of a poor QoL. The CDLQI will be used for adolescent participants (aged ≥ 12 to < 18 years) and pediatric participants (aged ≥ 6 to < 12 years); these participants will switch to the DLQI when they turn 18 years of age (if this happens during the study). The CDLQI will be completed with help from participant's caregivers. Data will be assessed to characterize disease burden and unmet need in Canadian msAD participants who initiate treatment with Dupixent.

WPAI-AD is designed to assess the impact of AD disease on the participant's productivity. It is a 6-item validated questionnaire to measure effect of your AD disease on your ability to work and perform regular activities over a 7-day recall period. The questionnaire ask participants to recall following types of activities during the previous 7 days: absenteeism (time missed), presenteeism (impairment/ reduced effectiveness), productivity, and activity impairment. Total WPAI-AD outcomes are expressed as impairment percentages, with higher numbers indicating greater impairment and less productivity. Caregivers complete the questionnaire for affected children. Data will be assessed to characterize disease burden and unmet need in Canadian msAD participants who initiate treatment with Dupixent.

WPAI-CIQ-AD is designed to asses the impact of AD disease on the participant's productivity. It is a 9-item validated questionnaire to measure participants ability to work, attend classes, and perform regular daily activities during the previous 7 days. Participants are asked to report the work time or classes lost due to AD disease; the impact of eczema on the performance in the workplace, at school, or during university classes; the effect of eczema on other daily activities during the previous 7 days. Total WPAI-AD outcomes are expressed as impairment percentages, with higher numbers indicating greater impairment and less productivity. Caregivers complete the questionnaire for affected children. Data will be assessed to characterize disease burden and unmet need in Canadian msAD participants who initiate treatment with Dupixent.

DFI is a 10-question disease-specific measure to assess the impact of AD disease on the QoL of the parents and family members of affected children (≥ 6 to < 18 years)'. The DFI is calculated by summing the score of each question with a maximum total score of 30 (higher scores indicate higher impact on life of family). Caregivers complete the questionnaire for affected children. Data will be assessed to characterize disease burden and unmet need in Canadian msAD participants who initiate treatment with Dupixent.

Data will be assessed to describe real-world treatment patterns in Canadian msAD participants who initiate treatment with Dupixent

Data will be assessed to describe real-world treatment patterns in Canadian msAD participants who initiate treatment with Dupixent

Data will be assessed to describe real-world treatment patterns in Canadian msAD participants who initiate treatment with Dupixent

Data will be assessed to describe real-world treatment patterns in Canadian msAD participants who initiate treatment with Dupixent

Data will be assessed to describe real-world treatment patterns in Canadian msAD participants who initiate treatment with Dupixent

Data will be assessed to describe real-world treatment patterns in Canadian msAD participants who initiate treatment with Dupixent

Data will be assessed to describe real-world treatment patterns in Canadian msAD participants who initiate treatment with Dupixent

Data will be assessed to describe real-world treatment patterns in Canadian msAD participants who initiate treatment with Dupixent

Data will be assessed to describe real-world treatment patterns in Canadian msAD participants who initiate treatment with Dupixent

Data will be assessed to describe real-world treatment patterns in Canadian msAD participants who initiate treatment with Dupixent

HADS is a 14-item scale, with 7 items relating to anxiety and 7 relating to depression. Each item on the questionnaire is scored from 0-3. The anxiety/depression score is the sum of the scores of the 7 related items; one can score between 0 and 21 for either anxiety or depression. The total score is the sum of the scores of the 14 items ranging from 0 (no symptoms) to 42 (severe symptoms), with higher scores indicating higher nxiety/depression complains. Data will be assessed to understand patterns and/or changes in non-atopic conditions in Canadian msAD participants who initiate treatment with Dupixen.

Participants will be asked to report the severity of their sleep disturbance during the past 7 days using a 0 (sleep not disturbed at all) to 10 (sleep extremely disturbed) NRS. Data will be assessed to understand patterns and/or changes in non-atopic conditions in Canadian msAD participants who initiate treatment with Dupixent.

Data will be assessed to understand patterns and/or changes in non-atopic conditions in Canadian msAD participants who initiate treatment with Dupixent

Data will be assessed to understand patterns and/or changes in non-atopic conditions in Canadian msAD participants who initiate treatment with Dupixent

Data will be assessed to understand patterns and/or changes in non-atopic conditions in Canadian msAD participants who initiate treatment with Dupixent

Data will be assessed for all demographic characteristics by age, sex, race and ethnicity, location to understand baseline characteristics and/or changes in Canadian msAD participants who initiate treatment with Dupixent, with co-existing type 2 inflammatory diseases.