{
  "abstract": "Background The Rapid Cough Questionnaire (RCQ) is a simplified three-item instrument developed as a pragmatic alternative to the Leicester Cough Questionnaire (LCQ). However, its performance across diverse respiratory diseases, particularly structural lung diseases, has not been sufficiently validated. This study evaluated the performance of the RCQ across major respiratory disease subgroups.Methods A total of 300 adult patients with chronic cough were prospectively enrolled from multiple respiratory centres. Participants completed five cough-specific instruments: Numeric Rating Scale (NRS), Cough Symptom Score (CSS), COugh Assessment Test (COAT), LCQ and RCQ. Construct validity was evaluated using correlation analyses across disease subgroups, including chronic obstructive pulmonary disease, asthma, idiopathic pulmonary fibrosis (IPF) and bronchiectasis.Results The RCQ showed strong correlations with the LCQ (r=0.93), COAT (r=−0.75), CSS (r=−0.62) and NRS (r=−0.59). These relationships remained robust among all aetiologies, with the correlation coefficients between RCQ and LCQ exceeding 0.88 in each subgroup. Bland-Altman plots and an intraclass correlation analysis indicated a high level of concordance between the RCQ and LCQ scores. The RCQ aligned closely with multidimensional symptom burden and maintained strong correlation with the LCQ even for IPF, where LCQ correlations with unidimensional tools (NRS or CSS) were attenuated.Conclusions The RCQ demonstrated strong cross-sectional concordance with the LCQ across heterogeneous respiratory conditions. Its brevity and consistent performance support its suitability in routine clinical practice and large-scale or longitudinal research settings. Further studies are warranted to evaluate its responsiveness and longitudinal performance.",
  "authors": [
    {
      "affiliations": [
        "Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Ilsan Paik Hospital, Inje University College of Medicine, Goyang, South Korea"
      ],
      "name": "Hyeon-Kyoung Koo"
    },
    {
      "affiliations": [
        "Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Yeouido St. Mary’s Hospital, The Catholic University of Korea College of Medicine, Seoul, South Korea"
      ],
      "name": "Tai Joon An"
    },
    {
      "affiliations": [
        "Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Uijeongbu St. Mary's Hospital, The Catholic University of Korea College of Medicine, Seoul, South Korea"
      ],
      "name": "Hyonsoo Joo"
    },
    {
      "affiliations": [
        "Division of Pulmonary, Allergy and Critical Care Medicine, Konkuk University Medical Center, Konkuk University School of Medicine, Seoul, South Korea"
      ],
      "name": "Chin Kook Rhee"
    },
    {
      "affiliations": [
        "Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Kyung Hee University Hospital at Gangdong, Kyung Hee University School of Medicine, Gangdong-gu, Seoul, South Korea"
      ],
      "name": "Yee Hyung Kim"
    },
    {
      "affiliations": [
        "Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, St. Vincent’s Hospital, The Catholic University of Korea College of Medicine, Seocho-gu, Seoul, South Korea"
      ],
      "name": "Sung-Kyoung Kim"
    },
    {
      "affiliations": [
        "Division of Pulmonary, Allergy, and Critical Care Medicine, Department of Internal Medicine, Korea University Guro Hospital, Korea University College of Medicine, Seoul, South Korea"
      ],
      "name": "Kyung Hoon Min"
    },
    {
      "affiliations": [
        "Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Seoul Metropolitan Government-Seoul National University Boramae Medical Center, Seoul National University College of Medicine, Jongno-gu, Seoul, South Korea"
      ],
      "name": "Deog Kyeom Kim"
    },
    {
      "affiliations": [
        "Division of Pulmonary, Allergy, and Critical Care Medicine, Department of Internal Medicine, Chung-Ang University College of Medicine, Dongjak-gu, Seoul, South Korea"
      ],
      "name": "Jong Wook Shin"
    },
    {
      "affiliations": [
        "Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Yeouido St. Mary's Hospital, The Catholic University of Korea College of Medicine, Seocho-gu, Seoul, South Korea"
      ],
      "name": "Hyoung Kyu Yoon"
    },
    {
      "affiliations": [
        "Division of Pulmonary, Allergy, and Critical Care Medicine, Department of Medicine, Hallym University Sacred Heart Hospital, Hallym University College of Medicine, Anyang, South Korea"
      ],
      "name": "Seung Hun Jang"
    },
    {
      "affiliations": [
        "Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Gangdong Sacred Heart Hospital, Hallym University, Seoul, South Korea"
      ],
      "name": "Yong Bum Park"
    },
    {
      "affiliations": [
        "Uijeongbu St. Mary's Hospital, Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, The Catholic University of Korea College of Medicine, Seocho-gu, Seoul, South Korea"
      ],
      "name": "Jin Woo Kim"
    },
    {
      "affiliations": [
        "Division of Pulmonary, Allergy and Critical Care Medicine, Department of Internal Medicine, Konkuk University Medical Center, Konkuk University School of Medicine, Gwangjin-gu, Seoul, South Korea"
      ],
      "name": "Ji-Yong Moon"
    },
    {
      "affiliations": [],
      "name": "Korean Cough Study Group in the Korean Academy of Tuberculosis and Respiratory Disease (KATRD)"
    }
  ],
  "title": "Clinical validation of the Rapid Cough Questionnaire across diverse lung diseases",
  "uid": "4687d0c8-d2bc-5390-adc6-5578bccc0da4"
}