The primary objective of this dataset is to determine the difference in the health-related quality of life (determined by SF-36) between patients with and without an established SARS-CoV-2 infection in a 12 month follow-up period in patients managed in general practice with more severe suspected COVID-19 infections (complicated respiratory tract infections), and to determine risk factors that influence recovery. Secondary objectives are to assess in patients who were suspected of having serious COVID-19 infections: differences in the different sections of the SF-36 from the index consultation to 12 months after the index consultation, the severity and duration of physical complaints and risk factors that influence recovery, the number of episodes of respiratory infections requiring antibiotic prescription, exacerbations of chronic disorders, hospital referrals, mortality within 12 months, number of contacts with GP, the extent of mental complaints or mental disorders and impact on daily activities Methods: Prospective cohort study in 35 Dutch general practices. Individuals aged ≥18 years who presented to their general practitioner (GP) with a moderately severe LRTI during the first COVID-19 waive in The Netherlands (March-June 2021) underwent serology testing (participants, GPs and study personnel remained blinded for serology outcomes during study conduct) and completed baseline and follow-up questionnaires. Dataset- Of the 443 patients with moderately severe LRTI that were approached for participation, 315 consented to participate. Of these, 277 (88%) were suitable for inclusion in the analyses. We obtained complete follow-up data in 97% of the 277 patients (Figure 1). The first follow-up questionnaire was completed after a median of 7.8 months (IQR 7·1-8·4) after the index consultation. Serology testing was performed after a median of 7·6 months (IQR 6·9-8·4). The SARS-CoV-2 serology test was positive in 19·9% (55/277) of participants. Participants with a positive serology test were older (mean age 59·9 years [SD 10·7] vs 54·8 years [SD 14·6]) and were more likely to have diabetes (20·0% vs 7·2%). Active smoking (17·1% vs 1·8%) and chronic pulmonary conditions (27·0% vs 10·9%) were more prevalent in SARS-CoV-2 serology negative participants.