South Korea Aged Animal-based food products Anthelmintics Article Body Mass Index Body mass index Bronchitis, Chronic COPD Chronic bronchitis Comorbidity Disease Progression Exacerbation Female Follow-Up Studies Humans Incidence Male Method validation Pulmonary Disease, Chronic Obstructive Republic of Korea Residue analysis Retrospective Studies Risk Assessment Risk Factors Severity of Illness Index Surveys and Questionnaires Tandem mass spectrometry acetic acid acetonitrile