Background: and Purpose Patients with cluster headache (CH) exhibit impaired health-related quality of life (HRQoL). However, there have been few studies related to the HRQoL of patients with CH from Asian backgrounds. This study aimed to determine the impact of CH on HRQoL and to identify the factors affecting HRQoL in patients with CH during cluster periods. Methods: This prospective study enrolled patients with CH from 17 headache clinics in South Korea between September 2016 and February 2021. The study aimed to determine HRQoL in patients with CH using the EuroQol 5 Dimensions (EQ-5D) index and the time trade-off (TTO) method. Age- and sex-matched headache-free participants were recruited as a control group. Results: The study included 423 patients with CH who experienced a cluster period at the time. EQ-5D scores were lower in patients with CH (0.88±0.43, mean±standard deviation) than in the controls (0.99±0.33, p<0.001). The TTO method indicated that 58 (13.6%) patients with CH exhibited moderate-to-severe HRQoL deterioration. The HRQoL states in patients with CH were associated with current smoking patterns, headache severity, frequency, and duration, and scores on the Generalized Anxiety Disorder 7-item scale (GAD-7), Patient Health Questionnaire 9-item scale (PHQ-9), 6-item Headache Impact Test, and 12-item Allodynia Symptom Checklist. Multivariable logistic regression analyses demonstrated that the HRQoL states in patients with CH were negatively correlated with the daily frequency of headaches, cluster period duration, and GAD-7 and PHQ-9 scores. Conclusions Patients with CH experienced a worse quality of life during cluster periods compared with the headache-free controls, but the degree of HRQoL deterioration varied among them. The daily frequency of headaches, cluster period duration, anxiety, and depression were factors associated with HRQoL deterioration severity in patients with CH.

Background: Chronic cough is a common symptom encountered by healthcare practitioners.The global prevalence of chronic cough is 9.6%, with a female predominance. The aim of our study is to reveal the sex differences in prevalence and severity of chronic cough in South Korea, stratified by age and etiology. Methods: This study included adult patients with chronic cough who were recruited from 19 respiratory centers in South Korea. Patients completed the cough numeric rating scale (NRS) and COugh Assessment Test (COAT) questionnaire to assess the severity and multidimensional impact of cough. Results: Among the 625 patients, 419 (67.0%) were females, with a male-to-female ratio of 1:2.03. The mean age was 49.4 years, and the median duration of cough was 12 weeks. The mean NRS and COAT scores were 5.5 ± 1.8 and 9.5 ± 3.6, respectively. Female patients were older (45.3 ± 15.4 vs. 51.6 ± 15.2, P < 0.001) and more likely to have asthma/cough variant asthma (CVA) (26.7% vs. 40.8%, P = 0.001) than male patients. There was no difference in the duration or severity of cough between sexes, regardless of the cause. The male-tofemale ratio was lower for upper airway cough syndrome (UACS), asthma/CVA, and gastroesophageal reflux disease (GERD), but not for eosinophilic bronchitis (EB) or unexplained cough. The mean age of female patients was higher in UACS and asthma/CVA, but not in EB, GERD, or unexplained cough. The majority (24.2%) fell within the age category of 50s. The proportion of females with cough increased with age, with a significant rise in the 50s, 60s, and 70–89 age groups. The severity of cough decreased in the 50s, 60s, and 70–89 age groups, with no significant sex differences within the same age group. Conclusion The sex disparities in prevalence and severity of cough varied significantly depending on the age category and etiology. Understanding the specific sex-based difference could enhance comprehension of cough-related pathophysiology and treatment strategies.

The International IgA Nephropathy Prediction Tool has been recently developed to estimate the progression risk of immunoglobulin A nephropathy (IgAN). This study aimed to evaluate the clinical performance of this prediction tool in a large IgAN cohort in Korea. Methods: The study cohort was comprised of 2,064 patients with biopsy-proven IgAN from four medical centers between March 2012 and September 2021. We calculated the predicted risk for each patient. The primary outcome was occurrence of a 50% decline in estimated glomerular filtration rate (eGFR) from the time of biopsy or end-stage kidney disease. The model performance was evaluated for discrimination, calibration, and reclassification. We also constructed and tested an additional model with a new coefficient for the Korean race. Results: During a median follow-up period of 3.8 years (interquartile range, 1.8–6.6 years), 363 patients developed the primary outcome. The two prediction models exhibited good discrimination power, with a C-statistic of 0.81. The two models generally underestimated the risk of the primary outcome, with lesser underestimation for the model with race. The model with race showed better performance in reclassification compared to the model without race (net reclassification index, 0.13). The updated model with the Korean coefficient showed good agreement between predicted risk and observed outcome. Conclusion: In Korean IgAN patients, International IgA Nephropathy Prediction Tool had good discrimination power but underestimated the risk of progression. The updated model with the Korean coefficient showed acceptable calibration and warrants external validation.

Background: Because the etiologies of bronchiectasis and related diseases vary significantly among different regions and ethnicities, this study aimed to develop a diagnostic bundle for bronchiectasis in South Korea. Methods: A modified Delphi method was used to develop expert consensus statements on a diagnostic bundle for bronchiectasis in South Korea. Initial statements proposed by a core panel, based on international bronchiectasis guidelines, were discussed in an online meeting and two email surveys by a panel of experts (≥70% agreement). Results: The study involved 21 expert participants, and 30 statements regarding a diagnostic bundle for bronchiectasis were classified as recommended, conditional, or not recommended. The consensus statements of the expert panel were as follows: A standardized diagnostic bundle is useful in clinical practice; diagnostic tests for specific diseases, including immunodeficiency and allergic bronchopulmonary aspergillosis, are necessary when clinically suspected; initial diagnostic tests, including sputum microbiology and spirometry, are essential in all patients with bronchiectasis, and patients suspected with rare causes such as primary ciliary dyskinesia should be referred to specialized centers. Conclusion Based on this Delphi survey, expert consensus statements were generated including specific diagnostic, laboratory, microbiological, and pulmonary function tests required to manage patients with bronchiectasis in South Korea.

Background: and Purpose Epidemiologic data suggest that cluster headache (CH) is significantly associated with cigarette smoking. The aim of this study was to determine differences in features between patients with a smoking history and those who are never-smokers, using data from a prospective multicenter registry. Methods: Data used in this study were obtained from the Korean Cluster Headache Registry that collected data from consecutive patients diagnosed with CH. We compared clinical and demographic features between ever-smokers (current or former smokers) and never-smokers. Results: This study enrolled 250 patients who were diagnosed with CH, of which 152 (60.8%) were ever-smokers and 98 (39.2%) were never-smokers. The age at CH onset was significantly lower in the never-smoker group than in the ever-smoker group [27.1±12.9 years vs. 30.6± 10.9 years (mean±standard deviation), p=0.024]. Seasonal rhythmicity (58.1% vs. 44.7%, p= 0.038) and triptan responsiveness (100% vs. 85.1%, p=0.001) were higher in never-smokers, while other clinical features such as pain severity, duration, attack frequency, and associated autonomic symptoms did not differ significantly between the groups. The male-to-female ratio was markedly higher in ever-smokers (29.4:1) than in never-smokers (1.7:1). Conclusions Most of the clinical features did not differ significantly between patients with a smoking history and never-smokers. However, the age at CH onset, sex ratio, and seasonal rhythmicity were significantly associated with smoking history.

Background: and Purpose Epidemiologic data suggest that cluster headache (CH) is significantly associated with cigarette smoking. The aim of this study was to determine differences in features between patients with a smoking history and those who are never-smokers, using data from a prospective multicenter registry. Methods: Data used in this study were obtained from the Korean Cluster Headache Registry that collected data from consecutive patients diagnosed with CH. We compared clinical and demographic features between ever-smokers (current or former smokers) and never-smokers. Results: This study enrolled 250 patients who were diagnosed with CH, of which 152 (60.8%) were ever-smokers and 98 (39.2%) were never-smokers. The age at CH onset was significantly lower in the never-smoker group than in the ever-smoker group [27.1±12.9 years vs. 30.6± 10.9 years (mean±standard deviation), p=0.024]. Seasonal rhythmicity (58.1% vs. 44.7%, p= 0.038) and triptan responsiveness (100% vs. 85.1%, p=0.001) were higher in never-smokers, while other clinical features such as pain severity, duration, attack frequency, and associated autonomic symptoms did not differ significantly between the groups. The male-to-female ratio was markedly higher in ever-smokers (29.4:1) than in never-smokers (1.7:1). Conclusions Most of the clinical features did not differ significantly between patients with a smoking history and never-smokers. However, the age at CH onset, sex ratio, and seasonal rhythmicity were significantly associated with smoking history.

BACKGROUND AND PURPOSE: Cluster headache (CH) can present with migrainous symptoms such as nausea, photophobia, and phonophobia. In addition, an overlap between CH and migraine has been reported. This study aimed to determine the differences in the characteristics of CH according to the presence of comorbid migraine. METHODS: This study was performed using data from a prospective multicenter registry study of CH involving 16 headache clinics. CH and migraine were diagnosed by headache specialists at each hospital based on third edition of the International Classification of Headache Disorders (ICHD-3). We interviewed patients with comorbid migraine to obtain detailed information about migraine. The characteristics and psychological comorbidities of CH were compared between patients with and without comorbid migraine. RESULTS: Thirty (15.6%) of 192 patients with CH had comorbid migraine, comprising 18 with migraine without aura, 1 with migraine with aura, 3 with chronic migraine, and 8 with probable migraine. Compared to patients with CH without migraine, patients with CH with comorbid migraine had a shorter duration of CH after the first episode [5.4±7.4 vs. 9.0±8.2 years (mean±standard deviation), p=0.008], a lower frequency of episodic CH (50.0% vs. 73.5%, p=0.010), and a higher frequency of chronic CH (13.3% vs. 3.7%, p=0.033). Psychiatric comorbidities did not differ between patients with and without comorbid migraine. The headaches experienced by patients could be distinguished based on their trigeminal autonomic symptoms, pulsating character, severity, and pain location. CONCLUSIONS: Distinct characteristics of CH remained unchanged in patients with comorbid migraine with the exception of an increased frequency of chronic CH. The most appropriate management of CH requires clinicians to check the history of preceding migraine, particularly in cases of chronic CH.
Classification ; Cluster Headache ; Comorbidity ; Headache ; Headache Disorders ; Humans ; Hyperacusis ; Migraine Disorders ; Migraine with Aura ; Migraine without Aura ; Nausea ; Photophobia ; Prospective Studies ; Specialization

BACKGROUND AND PURPOSE: Cluster headache (CH) is frequently either not diagnosed or the diagnosis is delayed. We addressed this issue by developing the self-administered Cluster Headache Screening Questionnaire (CHSQ). METHODS: Experts selected items from the diagnostic criteria of CH and the characteristics of migraine. The questionnaire was administered to first-visit headache patients at nine headache clinics. The finally developed CHSQ included items based on the differences in responses between CH and non-CH patients, and the accuracy and reliability of the scoring model were assessed. RESULTS: Forty-two patients with CH, 207 migraineurs, 73 with tension-type headache, and 18 with primary stabbing headache were enrolled. The CHSQ item were scored as follows: 3 points for ipsilateral eye symptoms, agitation, and duration; 2 points for clustering patterns; and 1 point for the male sex, unilateral pain, disability, ipsilateral nasal symptoms, and frequency. The total score of the CHSQ ranged from 0 to 16. The mean score was higher in patients with CH than in non-CH patients (12.9 vs. 3.4, p < 0.001). At a cutoff score of >8 points, the CHSQ had a sensitivity, specificity, positive predictive value, and negative predictive value of 95.2%, 96%, 76.9%, and 99.3%, respectively. CONCLUSIONS: The CHSQ is a reliable screening tool for the rapid identification of CH.
Cluster Headache* ; Diagnosis ; Dihydroergotamine ; Headache ; Headache Disorders, Primary ; Humans ; Male ; Mass Screening* ; Migraine Disorders ; Prevalence ; Sensitivity and Specificity ; Tension-Type Headache

BACKGROUND: Hepatitis B virus (HBV) infection leads to hepatic and extrahepatic manifestations including chronic kidney disease (CKD). However, the association between HBV and CKD is not clear. This study investigated the association between chronic HBV infection and CKD in a nationwide multicenter study. METHODS: A total of 265,086 subjects who underwent health-check examinations in 33 hospitals from January 2015 to December 2015 were enrolled. HBV surface antigen (HBsAg) positive cases (n = 10,048), and age- and gender-matched HBsAg negative controls (n = 40,192) were identified. CKD was defined as a glomerular filtration rate (GFR) < 60 mL/min/1.73 m² or proteinuria as at least grade 2+ of urine protein. RESULTS: HBsAg positive cases showed a significantly higher prevalence of GFR < 60 mL/min/1.73 m² (3.3%), and proteinuria (18.9%) than that of the controls (2.6%, P < 0.001, and 14.1%, P < 0.001, respectively). In the multivariate analysis, HBsAg positivity was an independent factor associated with GFR < 60 mL/min/1.73 m² along with age, blood levels of albumin, bilirubin, anemia, and hemoglobin A1c (HbA1c). Likewise, HBsAg positivity was an independent factor for proteinuria along with age, male, blood levels of bilirubin, protein, albumin, and HbA1c. A subgroup analysis showed that HBsAg positive men but not women had a significantly increased risk for GFR < 60 mL/min/1.73 m². CONCLUSION: Chronic HBV infection was significantly associated with a GFR < 60 mL/min/1.73 m² and proteinuria (≥ 2+). Therefore, clinical concern about CKD in chronic HBV infected patients, especially in male, is warranted.
Anemia ; Antigens, Surface ; Bilirubin ; Case-Control Studies* ; Female ; Glomerular Filtration Rate ; Hepatitis B Surface Antigens ; Hepatitis B virus ; Hepatitis B, Chronic* ; Hepatitis, Chronic* ; Humans ; Male ; Multivariate Analysis ; Prevalence ; Proteinuria ; Renal Insufficiency, Chronic*

Cluster headache (CH) is a rare underdiagnosed primary headache disorder with very severe unilateral pain and autonomic symptoms. Clinical characteristics of Korean patients with CH have not yet been reported. We analyzed the clinical features of CH patients from 11 university hospitals in Korea. Among a total of 200 patients with CH, only 1 patient had chronic CH. The average age of CH patients was 38.1 ± 8.9 years (range 19–60 years) and the average age of onset was 30.7 ± 10.3 years (range 10–57 years). The male-to-female ratio was 7:1 (2.9:1 among teen-onset and 11.7:1 among twenties-onset). Pain was very severe at 9.3 ± 1.0 on the visual analogue scale. The average duration of each attack was 100.6 ± 55.6 minutes and a bout of CH lasted 6.5 ± 4.5 weeks. Autonomic symptoms were present in 93.5% and restlessness or agitation was present in 43.5% of patients. Patients suffered 3.0 ± 3.5 (range 1–25) bouts over 7.3 ± 6.7 (range 1–30) years. Diurnal periodicity and season propensity were present in 68.5% and 44.0% of patients, respectively. There were no sex differences in associated symptoms or diurnal and seasonal periodicity. Korean CH patients had a high male-to-female ratio, relatively short bout duration, and low proportion of chronic CH, unlike CH patients in Western countries.
Age of Onset ; Asia ; Cluster Headache* ; Delayed Diagnosis ; Dihydroergotamine ; Headache Disorders, Primary ; Hospitals, University ; Humans ; Korea* ; Periodicity ; Psychomotor Agitation ; Seasons ; Sex Characteristics ; Sex Ratio ; Trigeminal Autonomic Cephalalgias