Background: Chronic cough (CC) is a common reason for a physicians visit1. Since 2020 refractory chronic cough (RCC - specific underlying condition, refractory to therapy) and unexplained chronic cough (UCC ? without any detectable cause) are defined as separate entities2. Due to the absence of an ICD-10 code, the prevalence of CC, RCC/UCC in Germany is unknown

Objectives: To evaluate the prevalence of CC, RCC/UCC

Methods: VICHAS was a prospective observational study conducted from 01.01.-31.12.2020 in 16 outpatient respiratory care offices (RCO) in Germany. We included all patients (pts) with CC/RCC/UCC to calculate prevalence data. A stepwise extrapolation was performed: 1. Collected data from the participating sites were extrapolated to the number of CC, RCC/UCC pts in all RCOs in Germany. With the help of prescription data (asthma) conversion to absolute numbers was obtained. 2. Two different assumptions were made regarding the frequency of referral of CC pts to RCOs (14% and 43%). They provided the framework for the upper & lower limits for prevalence. 3. Prevalence calculation and estimation was performed in relation to German adult population

Results: Overall 2,937 CC pts were documented, RCC/UCC: 421. Extrapolations resulted in national prevalence estimates (depending on referral assumption) for RCC/UCC: 0.49% and 1.50%; CC: 0.83% and 2.32%

Limitations: COVID-19, small number of sites & pts

Conclusion: The survey provides solid estimates on the prevalence of CC, RCC/UCC pts in the German adult population in clinical practice, which is lower compared to studies in other countries

1. Schappert SM, Vital Health Stat 2006,1-66

2. Kardos P, Respir Med. 2020,170:10593