Decreasing Attacks and Improving Quality of Life through a Systematic Management Program for Patients with Hereditary Angioedema.

INTRODUCTION: Prevention of attacks is a major goal in management of patients with hereditary angioedema (HAE). We aimed to investigate the effects of a systematic intervention for HAE patients. METHODS: Thirty-three patients with HAE with C1-inhibitor deficiency, belonging to a single family, participated in a management program coordinated by an allergist/immunologist. Angioedema attacks before intervention were ascertained by interviews and emergency room charts and recorded prospectively by patients or caregivers after enrollment. Mean number of attacks/month was compared at 12 months preintervention and 8 and 14 months within intervention. Patient-reported outcome instruments were used to assess quality of life, including HAE Quality of Life (HAE-QoL) questionnaire, psychological conditions, and work impairment, at baseline and 8 and 14 months within intervention. Data were stored in REDCap platform and analyzed by adjusted Bayesian models of double Poisson regression. RESULTS: Mean number of attacks/month significantly decreased (95% credible interval [CrI] excluding 0) from 1.15 preintervention to 0.25 and 0.23, 8 and 14 months within intervention, with mean decreases of -0.89 (95% CrI: -1.21 to -0.58) and -0.92 (95% CrI: -1.22 to -0.60), respectively. HAE-QoL scores showed mean total increases of 15.2 (95% CrI: 1.23-29.77) and 26 (95% CrI: 14.56-39.02) at 8 and 14 months within the study, as compared to baseline, revealing marked improvement in quality of life. Significant increase in role-emotional and reduction of depression, stress, and anxiety were observed at 14 months. CONCLUSION: A systematic approach integrating HAE-specific care with effective handling of psychological issues decreased the number of attacks and improved quality of life, targets for best practice in HAE.

Psychology and hereditary angioedema: A systematic review.

Background: Hereditary angioedema (HAE) is caused by mutations in the C1 inhibitor (C1-INH) gene Serpin Family G Member 1(SERPING1), which results in either the decreased synthesis of normal C1-INH (C1-INH-HAE type I) or expression of unfunctional C1-INH (C1-INH-HAE type II). In recent studies, emotional stress was reported by patients as the most common trigger factor for C1-INH-HAE attacks. Moreover, patients reported considerable distress over the significant variability and uncertainty with which the disease manifests, in addition to the impact of physical symptoms on their overall quality of life. Objective: We did a systematic review of the literature to shed light on the advancements made in the study of how stress and psychological processes impact C1-INH-HAE. Methods: All of the articles on C1-INH-HAE were analyzed up to December 2019. Both medical data bases and psychological data bases were examined. The keywords (KWs) used for searching the medical and psychological data bases were the following: "hereditary angioedema," "psychology," "stress," "anxiety," and "depression." Results: Of a total of 2549 articles on C1-INH-HAE, 113 articles were retrieved from the literature search by using the related KWs. Twenty-one of these articles were retrieved, examined, and classified. Conclusion: Although the literature confirmed that stress may induce various physical diseases, it also warned against making simplistic statements about its incidence that did not take into account the complexity and multicausality of factors that contribute to C1-INH-HAE expression.

Effect of COVID-19 on hereditary angioedema activity and quality of life.

Background: The demonstration that severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) enters the cell via the angiotensin-converting enzyme 2 receptor has raised concerns that, in hereditary angioedema (HAE), a disease characterized by bradykinin-mediated angioedema attacks, coronavirus disease 2019 (COVID-19) may trigger angioedema attacks, increase the frequency and/or severity of attacks, or cause more severe symptoms of COVID-19. Objective: The objective was to evaluate the severity of COVID-19 in patients with HAE, the course of HAE attacks, angioedema activity, and the quality-of-life scores during COVID-19 pandemic. Methods: Patients diagnosed with HAE for at least 6 months were included in the study. The 7-day Angioedema Activity Score and the Angioedema Quality of Life (AE-QoL) Questionnaire were first completed at the onset of the pandemic between March 12 and June 1, 2020, then during SARS-CoV-2 infection, and in the third month after recovering from COVID-19. Results: Ten of 67 patients with HAE (14.9%) were diagnosed with COVID-19. The median (interquartile range) age of the 10 patients diagnosed with COVID-19 was 35.5 years (28.0-55.0 years). Six of the 10 patients (60%) were women. During COVID-19, five of the 10 patients (50%) had no angioedema attack. Two patients with severe HAE experienced a significant increase in angioedema activity during COVID-19 compared with their basal activity scores. The remaining three patients had a similar or lower attack frequency than their basal level. Four (40%) of the 10 patients had a relative increase in their attacks during the convalescence period. There was no statistically significant difference among pre-COVID-19, during COVID-19 and post-COVID-19 periods in function, mood, fear and/or shame, nutrition, and total scores of the AE-QoL Questionnaire although the fear dimension was relatively more affected (p = 0.06). Conclusion: Although the sample size was small, analysis of our data supported that the symptoms of COVID-19 were not more severe in HAE. Also, there was no significant difference in the AE-QoL Questionnaire scores, the frequency, and severity of angioedema attacks during the course of COVID-19 in the patients with HAE.

Prospective Analysis in Patients With HAE Under Prophylaxis With Lanadelumab: A Real-life Experience.

BACKGROUND AND OBJECTIVES: Patients with the rare disease hereditary angioedema (HAE) suffer from recurrent acute attacks of edema. There is no curative therapy, but the frequency of attacks and quality of life of severely affected patients can be improved by prophylactic therapy. The monoclonal antibody lanadelumab has been approved for routine prophylaxis in patients with HAE since November 2018. PATIENTS AND METHODS: In this prospective assessment, a long-term therapy with lanadelumab was initiated in 12 adult patients with HAE. We analyzed their course of disease 6 months after the start of long-term prophylactic therapy using a validated quality-of-life questionnaire and evaluated the frequency and severity of attacks as well as side effects. Furthermore, the therapy with lanadelumab was compared with the previous medication. RESULTS: To date, our study is the first prospective quality of life analysis in HAE patients under treatment with lanadelumab in real life conditions. Mean attack frequencies were reduced from 6.4 to 0.3 attacks per month and patient in our cohort (P<0.0001). No severe attacks occurred under lanadelumab prophylaxis. In all patients, quality of life increased significantly. CONCLUSIONS: Lanadelumab is an effective but expensive long-term prophylaxis for HAE patients. A favorable side-effect profile has been shown. J Drugs Dermatol. 2020;19(10):978-983. doi:10.36849/JDD.2020.5269.

The relationship between anxiety and quality of life in children with hereditary angioedema.

BACKGROUND: The severe life-threatening characteristics of hereditary angioedema (HAE) with C1-inhibitor deficiency (C1-INH-HAE) can affect anxiety levels among pediatric patients. This emotional burden together with the physical restrictions of C1-INH-HAE may decrease children's health-related quality of life (HRQoL). OBJECTIVES: (i) To compare anxiety state and trait between children with C1-INH-HAE and healthy controls; (ii) to examine the relationship between the level of anxiety of children with C1-INH-HAE, their disease activity/affected sites and their HRQoL; and (iii) to predict the HRQoL of children with C1-INH-HAE based on their anxiety level and disease activity/affected sites METHODS: Thirty-three children with C1-INH-HAE (aged 5-18 years) and 52 healthy controls were recruited from Israel and Hungary. All children completed the State-Trait Anxiety Inventory for Children (STAIC), the Pediatric Quality of Life Inventory (Peds-QL) demographic questionnaire and a disease activity and site questionnaire . Disease activity was defined as the number of attacks in last year. RESULTS: Both anxiety state and trait were significantly higher among children with C1-INH-HAE as compared to the controls (44.74±10.56 vs 38.76±10.67, P<.01, 29.21±5.16 vs 25.23±4.09, P<.001 in comparison). Significant differences were found between C1-INH-HAE patients with HAE attacks, asymptomatic C1-INH-HAE patients, and healthy controls in both anxiety state (F56,2 =4.69, P=.001) and trait (F56,2 =9.06, P<.0001). A higher anxiety trait was correlated with the number of angioedema-affected sites (r=.52, P=.003). The presence of HAE attacks and higher anxiety trait predicted a lower HRQoL in children with C1-INH-HAE. CONCLUSIONS: C1-INH-HAE children have higher anxiety trait and state, which correlate with reduced HRQoL domains.

Health-related quality of life in Danish children with hereditary angioedema.

BACKGROUND: The potentially life-threatening disease hereditary angioedema with C1-inhibitor deficiency (C1-INH-HAE) can have considerable impact on the health-related quality of life (HRQoL) in adult patients. Half the patients with C1-INH-HAE develop symptoms before the age of 10 years. However, the HRQoL in children with C1-INH-HAE is almost unexplored. OBJECTIVE: To investigate HRQoL in Danish children with C1-INH-HAE, including possible correlations to disease severity and attack frequency. METHODS: All Danish children ages 2-18 years with C1-INH-HAE were invited to complete questionnaires regarding HRQoL; 14 (93%) agreed. Child self-report forms were used for children ages ≥5 years. The instruments used were the PedsQL (Child Self-Report and Parent Proxy-Report forms); the Children's Dermatology Life Quality Index; a nonvalidated, disease-specific quality-of-life questionnaire; and two visual analog scales that rated general health. RESULTS: The HRQoL scores in our study were comparable with the normal scores for healthy children and better than the scores in the only other study dedicated to HRQoL in children. Children with recent attacks had lower scores, whereas HRQoL scores were not correlated to overall disease severity or age. Surprisingly, home therapy was associated with lower HRQoL; however, home therapy was also correlated to a higher overall severity score and more frequent attacks. There was a strong child-parent agreement in the PedsQL forms, but scores were independent of whether the child had a family history of C1-INH-HAE or sporadic C1-INH-HAE and whether the parent completing the Parent Proxy-Report form carried the disease. CONCLUSION: Overall, the children assessed on average had a normal HRQoL and better than those with other common skin disorders. However, according to our findings, health care providers should be especially attentive to HRQoL when children with C1-INH-HAE become symptomatic.

Health-related quality of life in relation to disease activity in adults with hereditary angioedema in Sweden.

BACKGROUND: Health-related quality of life (HR-QoL) is impaired in patients with hereditary angioedema (HAE) but has not yet been satisfactorily described. OBJECTIVE: To study HR-QoL in patients with HAE by combining different HR-QoL instruments with disease activity assessment. METHODS: All adults in the Swedish HAE registry were invited to take part in this questionnaire study, which used the generic HR-QoL instruments, EuroQol 5 Dimensions 5 Level (EQ-5D-5L) and the RAND Corporation Short Form 36 (RAND-36), the disease-specific Angioedema Quality of Life instrument (AE-QoL), the recently introduced Angioedema Activity Score (AAS) form, and questionnaires on sick leave and prophylactic medication. RESULTS: Sixty-four of 133 adults (26 men, 38 women) between 18 and 91 years old responded. The most affected HR-QoL dimensions in the EQ-5D-5L were pain/discomfort and anxiety/depression; in the RAND-36, energy/fatigue, general health, pain; and, in the AE-QoL, fears/shame and fatigue/mood. Women had lower HR-QoL in the RAND-36 for general health and energy/fatigue (p < 0.05). Patients who reported any AAS of >0 had significantly impaired HR-QoL. There were significant associations (p < 0.05) between the AAS and EQ-5D-5L, between the AAS and all dimensions of the RAND-36 except physical function, and between the AAS and AE-QoL in all dimensions. Nine of 36 patients who reported sick leave during the previous 4 weeks had significantly impaired HR-QoL in all the instruments (p < 0.05). There was no significant difference in HR-QoL in the patients with and the patients without prophylactic medication, except for the nutrition dimension of the AE-QoL (p < 0.05). CONCLUSION: Comprehensive information is obtained by combining different HR-QoL instruments. Pain, anxiety/depression, and fatigue/mood are important aspects of HAE but the AE-QoL disregards pain. HR-QoL was not significantly affected by prophylaxis. Increased disease activity was associated with impaired HR-QoL, which justifies more active disease management.

Swedish children with hereditary angioedema report good overall health and quality of life despite symptoms.

AIM: Few studies have been published on children with hereditary angioedema (HAE), an autosomal dominant disease caused by mutations on chromosome 11. This study explored various aspects of the disease in the Swedish paediatric population. METHODS: A retrospective questionnaire was sent to all 36 Swedish children known to have HAE, and a physician carried out follow-up telephone interviews. RESULTS: Most of the questionnaires were completed by the parents of 31 (86%) children with HAE, with or without their input, at a median age of nine years (range 1-17), and the physician also interviewed 29. HAE symptoms were experienced by 23 children, including abdominal attacks (96%), skin swelling (78%) and swelling in the mouth and/or upper airways (52%). Psychological stress was the most common trigger for abdominal attacks and trauma and sports triggered skin swelling. The majority (n = 19) had access to complement-1 esterase inhibitor concentrate at home. Current health and quality of life were generally rated as good, independent of whether the child had experienced HAE symptoms or not. CONCLUSION: Most children with HAE had experienced abdominal attacks and skin swelling, but their overall health and quality of life were generally perceived to be good.

Patients perception of self-administrated medication in the treatment of hereditary angioedema.

BACKGROUND: Early therapy of hereditary angioedema (HAE) decreases morbidity, improves outcomes, decreases absenteeism, and possibly decreases mortality. This can be accomplished best with self-therapy. Previously, the authors examined barriers to self-therapy from the perspective of the nurse and the physician, but data are lacking on what patients perceive as major barriers to self-administered therapy for HAE. OBJECTIVE: To identify those barriers in a prospective fashion by patient interview. METHODS: After approval from the institutional review board, a telephone survey was performed of patients with HAE from a database of patients who were recently seen in the clinic. The survey focused on anxiety, depression, stress, concerns regarding method of administration, the ability to inject themselves, and what they perceived as barriers to providing self-care. RESULTS: Ninety-two patients were contacted and 59 agreed to participate. With 69% of those patients currently undergoing self-administered treatment, the results showed minimal depression and anxiety, a high satisfaction with treatment, and significant compliance with treatment. Most of those not yet on self-administered therapy wanted to start despite being satisfied with the care received in the emergency department. They also believed care at home would be optimal. The main concern of the 2 groups was not being able to treat themselves in the event of an HAE attack. CONCLUSION: From these data, it is obvious that most patients are willing to self-treat. This suggests that physicians should encourage self-treatment of HAE to improve outcomes and quality of life of patients with HAE.

Development and content validity testing of a patient-reported outcomes questionnaire for the assessment of hereditary angioedema in observational studies.

BACKGROUND: Hereditary Angioedema (HAE), a rare genetic disease, manifests as intermittent, painful attacks of angioedema. Attacks vary in frequency and severity and include skin, abdominal and life-threatening laryngeal swellings. This study aimed to develop a patient reported outcome (PRO) tool for the assessment of HAE attacks, including their management and impact on patients' lives, for use in clinical studies, or by physicians in general practice. METHODS: The results of open-ended face to face concept elicitation interviews with HAE patients in Argentina (n = 10) and the US (n = 33) were used to develop the first draft questionnaire of the HAE patient reported outcomes questionnaire (HAE PRO). Subsequently, in-depth cognitive debriefing interviews were performed with HAE patients in the UK (n = 10), Brazil (n = 10), Germany (n = 11) and France (n = 12). Following input from eight multinational clinical experts further cognitive interviews were conducted in the US (n = 12) and Germany (n = 12). Patients who experienced abdominal, cutaneous or laryngeal attacks of varying severity levels were included in all rounds of interviews. Across the rounds of interviews patients discussed their HAE attack symptoms, impacts and treatments. Cognitive debriefing interviews explored patient understanding and relevance of questionnaire items. All interviews were conducted face to face following a pre-defined semi-structured interview guide in the patient's native language. RESULTS: Patients reported a variety of HAE symptoms, attack triggers, warning signs, attack impacts and treatment options which were used to develop the HAE PRO. The HAE PRO was revised and refined following input from patients and clinical experts. The final 18-item HAE PRO provides an assessment of the HAE attack experience including symptoms, impacts, treatment requirements, healthcare resource use and loss of productivity caused by HAE attacks. CONCLUSIONS: Patient and expert input has contributed to the development of a content valid questionnaire that assesses concepts important to HAE patients globally. HAE patients across cultures consider the HAE PRO a relevant and appropriate assessment of HAE attacks and treatment.

Burden of Illness in Hereditary Angioedema: A Conceptual Model.

The objective of the Hereditary Angioedema Burden of Illness Study in Europe was to assess the real-world experience of hereditary angioedema (HAE) from the patient perspective. Based on open-ended qualitative interviews with 30 patients from Spain, Germany and Denmark, 5 key themes emerged characterizing the impact of HAE on health-related quality of life (HRQoL): (i) unnecessary treatments and procedures, (ii) symptom triggers, (iii) attack impacts, (iv) caregiver impacts, and (v) long-term impacts. Patients for example experience unnecessary medical procedures due to diagnostic delays; anxiety and fear about attacks, and passing HAE to children; reduced work/school productivity; and limited career/educational achievement. Patient caregivers also experience worry and work/activity interruption during the attacks. In conclusion, a conceptual model was developed illustrating the hypothesized relationships among the wide-ranging short- and long-term HRQoL impacts of HAE. These findings can be used to highlight important issues in clinical management, raise awareness of the patients' experience among policymakers and help guide measurement of HRQoL outcomes in future studies in HAE.

Before and after, the impact of available on-demand treatment for HAE.

Availability of effective treatment for acute attacks is expected to transform the care of hereditary angioedema (HAE) patients. We felt that it would be of interest to test these assumptions by examining the perceptions of HAE patients regarding the impact that these therapies have had on their lives. Patients at a United States HAE Association summit meeting were asked to rate the burden of HAE currently and compare by recall with 2009 when these therapies were not available. Questions covered five domains: psychological/emotional status, ability to carry out daily activities, fear of suffocation, worry about their children inheriting HAE, and medication side effects. Data were analyzed using Wilcoxon signed-rank tests or analysis of variance. Responses were obtained from 134 self-identified HAE subjects: 85 type I, 21 type II, and 28 with normal C1 inhibitor (C1INH). Burden of disease showed significant improvement in all domains except worry about children inheriting HAE. With the introduction of newer therapies, subjects with the most severe burden of illness improved more than those with milder burdens. However, significant burden of illness remained. The availability of the current treatments has substantially improved the quality of life for HAE patients in the United States, similar to a survey of Danish HAE patients regarding the introduction of home treatment. Nevertheless, our study shows that a substantial burden of illness remains for HAE patients.

Hereditary angioedema - consequences of a new treatment paradigm in Denmark.

Experiences from a Danish patient cohort with hereditary angioedema are reported with focus on home therapy and burden of illness. Eighty patients have been prospectively followed over 11 years, having experienced a total of 7,809 attacks over 469 patient years. More than half of the patients stopped long-term prophylaxis with danazol or tranexamic acid and changed treatment regimen to on-demand treatment with C1 inhibitor concentrate or icatibant. At least 10% of the attacks remained un-treated. More than half of the patients felt that hereditary angioedema had a significant psychological impact on their lives and restricted their physical activities. By December 2012, a total of 39 patients (49%) were practicing home treatment of acute attacks. Home therapy reduced the mean number of acute hospital visits by 84% and significantly improved burden of illness items. In conclusion, home therapy has profoundly improved the lives of hereditary angioedema patients.

The humanistic burden of hereditary angioedema: results from the Burden of Illness Study in Europe.

Hereditary angioedema (HAE) is a rare but potentially life-threatening disease marked by spontaneous, recurrent attacks of swelling. The broad range of consequences of HAE on patients' lives is not well understood. The study objective was to comprehensively characterize the burden of illness and impact of HAE types I and II from the patient perspective. The HAE Burden of Illness Study in Europe was conducted in Spain, Germany, and Denmark to assess the real-world experience of HAE from the patient perspective via a one-time survey, which included items on clinical characteristics and physical and emotional impacts. One hundred eighty-six patients participated; 59% reported having an attack at least once a month, 67% reported moderate-to-severe pain during their last attack, and 74% reported moderate-to-severe swelling. The most common sites of the last attack were the abdomen and extremities; 24% experienced an attack in more than one site. The impact of HAE on daily activities was high during attacks and did not vary significantly by body site affected; patients also reported that HAE impacted their daily activities between attacks. Patients reported substantial anxiety about future attacks, traveling, and passing HAE to their children. Based on Hospital Anxiety and Depression Scale scores, 38 and 14% had clinically meaningful anxiety and depression, respectively. Despite standard of care, HAE patients still have frequent and painful attacks. Patients experience substantial impairment physically and emotionally both during and between attacks. A better understanding of these effects may help in the clinical management of HAE patients.

Quantifying the burden of disease and perceived health state in patients with hereditary angioedema in Sweden.

Hereditary angioedema (HAE) due to C1 inhibitor deficiency is a rare disease characterized by attacks of edema, known to impact quality of life (QoL). This study investigates the burden of HAE in Swedish patients, both children and adults. We used a retrospective registry study of Swedish patients with HAE, captured by the Sweha-Reg census. Data were collected using a paper-based survey. Patients completed EuroQoL 5 Dimensions 5 Levels (EQ5D-5L) questionnaires for both the attack-free state (EQ5D today), and the last HAE attack (EQ5D attack). Questions related to patient's age and sex and other variables, such as attack location and severity, were included to better understand the burden of HAE. EQ5D-5L values were estimated for the two HAE disease states. Patient-reported sick leave was also analyzed. A total of 103 responses were analyzed from 139 surveys (74% response rate). One hundred one reported an EQ5D today score (mean, 0.825) and 78 reported an EQ5D attack score (mean, 0.512) with significant differences between the two states (p < 0.0001). This difference was observed for both mild (p < 0.05), moderate (p < 0.0001), and severe attacks (p < 0.0001). Attack frequency had a negative effect on EQ5D today. Patients with >30 attacks a year had a significantly lower EQ5D today score than those with less frequent attacks. Of 74 participants, 33 (44.6%) had been absent from work or school during the latest attack and, of those with a severe attack, 81% had been absent. HAE has a significant impact on QoL both during and between attacks and on absenteeism during attacks.

The real life experience goes on: update after 4 years on the first cohort treated with lanadelumab at our center.

Introduction: Lanadelumab is a first-line long-term prophylaxis (LTP) in hereditary angioedema (HAE). Real-life data on its long-term efficacy and safety are limited. It is unknown whether patients using lanadelumab need short-term prophylaxis (STP). Objectives: To provide 4-year follow-up data for our first 34 patients treating with lanadelumab. Methods: Patients were assessed for their current injection interval, attacks, treatment satisfaction, disease control (AECT), quality of life impairment (AE-QoL), events that can induce attacks, and the use of STP since the start of their treatment with lanadelumab. Results: Of 34 patients who started lanadelumab treatment, 32 were still using it after 4 years, with a median injection interval of 33 (range 14-90) days. HAE patients (n=28) reported longer intervals, i.e. 35 (14-90) days, than patients with angioedema due to acquired C1 inhibitor deficiency (n=4, 23 (14-31) days). With their current injection intervals, used for a mean duration of 29 ± 17 months, patients reported a yearly attack rate of 0.3 ± 0.1. More than 70% of patients were attack-free since starting their current injection interval. All patients reported well-controlled disease, i.e. ≥10 points in the AECT; 21 patients had complete control (16 points). AE-QoL scores improved further compared to our initial report, most prominently in the fears/shame domain (-6 points). Treatment satisfaction was very high. No angioedema occurred after 146 of 147 potentially attack-inducing medical procedures without STP. Conclusions: Our results demonstrate the long-term efficacy and safety of lanadelumab in real-life and question the need for STP in patients who use effective LTP.

Challenges of C1-inhibitor concentrate self-administration.

Self-administration of therapy can help hereditary angioedema (HAE) patients regain control of their disease or reduce its impact and improve the quality of their lives. However, data from a self-administration survey, and subsequent discussion at an international HAE expert meeting, identified several barriers to self-administration therapy. These barriers include difficulty in administration technique, availability of nursing resources and the mental capacity of the patient. Encouragingly, international HAE experts identified that once a patient has acquired self-administration skills, they generally retain them in the long-term. As patient uptake increases, it was recommended that follow-up management plans should be established to address any issues from the patient's perspective.

Development of a disease-specific quality of life questionnaire for adult patients with hereditary angioedema due to C1 inhibitor deficiency (HAE-QoL): Spanish multi-centre research project.

BACKGROUND: There is a need for a disease-specific instrument for assessing health-related quality of life in adults with hereditary angioedema due to C1 inhibitor deficiency, a rare, disabling and life-threatening disease. In this paper we report the protocol for the development and validation of a specific questionnaire, with details on the results of the process of item generation, domain selection, and the expert and patient rating phase. METHODS/DESIGN: Semi-structured interviews were completed by 45 patients with hereditary angioedema and 8 experts from 8 regions in Spain. A qualitative content analysis of the responses was carried out. Issues raised by respondents were grouped into categories. Content analysis identified 240 different responses, which were grouped into 10 conceptual domains. Sixty- four items were generated. A total of 8 experts and 16 patients assessed the items for clarity, relevance to the disease, and correct dimension assignment. The preliminary version of the specific health-related quality of life questionnaire for hereditary angioedema (HAE-QoL v 1.1) contained 44 items grouped into 9 domains. DISCUSSION: To the best of our knowledge, this is the first multi-centre research project that aims to develop a specific health-related quality of life questionnaire for adult patients with hereditary angioedema due to C1 inhibitor deficiency. A preliminary version of the specific HAE-QoL questionnaire was obtained. The qualitative analysis of interviews together with the expert and patient rating phase helped to ensure content validity. A pilot study will be performed to assess the psychometric properties of the questionnaire and to decide on the final version.