Survey Reveals Prevalence of Chronic, Subacute Cough Among Patients in Japan

A web-based survey used to identify the prevalence estimate and characteristics of patients with chronic cough and subacute cough in Japan provides new information about an otherwise poorly studied population, reported BMJ Open Respiratory Research.

Previous research estimated that the prevalence of cough in Japan is 10.2% and that 23.2% of the cough population experienced chronic cough. The same research reported that more than 60% of patients with cough reported that they did not see a physician for their condition.

The current study sought to supplement previous research regarding prevalence and characteristics of patients with chronic cough. Data were used to compare characteristics and cough severity among patients with chronic cough who reported low satisfaction rates with treatment effectiveness and summarize causes and treatment use among patients with chronic cough.

Data regarding chronic cough status and cough-specific characteristics and experience were gleaned from an observational, cross-sectional online 2019 Japan National Health and Wellness Survey and a supplemental chronic cough survey. The study population consisted of 378 patients with subacute cough who self-reported having cough for 3—8 weeks and 568 patients with chronic cough who self-reported having cough for more than 8 weeks during any period in the past 12 months.

Findings showed:

• The point prevalence of chronic cough was 2.89% and 12-month period prevalence was 4.29%.
• The point prevalence of subacute cough was 2.04% and the 12-month period prevalence was 5.66%.
• The point prevalence and 12-month period prevalence of chronic cough was highest in males aged 60 or older (3.85%).
• Subacute cough had the highest point prevalence in males younger than 60 years old (2.73%), and its 12-month period prevalence was highest in females younger than 60 years old (6.71%).
• The most common chronic cough related illnesses were allergic rhinitis (10.3%), asthma (9.6%), and cough variant asthma (8.5%).
• Half of the patients (51.2%) did not use any medications and less than half (44.2%) of patients with chronic cough had discussed their cough with a physician.
• Inhaled steroids (29.8%) and inhaled corticosteroid and long acting β2-agonist (33.3%) were reported as the most effective medications by about one-third of patients taking them.
• Among all patients with current chronic cough, 91 (16.0%) reported low satisfaction rates with treatment effectiveness.
• Compared with other patients with chronic cough, patients who reported low satisfaction rates with treatment effectiveness experienced significantly greater cough severity.

The study data suggests that an unmet need for better diagnosis and treatments for chronic cough exists and should be mitigated, as cough is the most common reason for outpatient clinic and hospital visits in Japan. Mitigation strategies are especially critical for those who reported low satisfaction rates in treatment effectiveness and experienced worse cough severity.

Reference

Tobe K, Kubo T, Okuyama K, et al. Web-based survey to evaluate the prevalence of chronic and subacute cough and patient characteristics in Japan. BMJ Open Respir Res. 2021;8(1):e000832. doi:10.1136/bmjresp-2020-000832