BackgroundAntibiotics are prescribed to >70% of patients presenting in primary care with an acute exacerbation of chronic obstructive pulmonary disease (AECOPD). The PACE randomised controlled trial found that a C-reactive protein point-of-care test (CRP-POCT) management strategy for AECOPD in primary care resulted in a 20% reduction in patient-reported antibiotic consumption over 4 weeks.AimTo understand perceptions of the value of CRP-POCT for guiding antibiotic prescribing for AECOPD; explore possible mechanisms, mediators, and pathways to effects; and identify potential barriers and facilitators to implementation from the perspectives of patients and clinicians.Design and settingQualitative process evaluation in UK general practices.MethodSemi-structured telephone interviews with 20 patients presenting with an AECOPD and 20 primary care staff, purposively sampled from the PACE study. Interviews were audio-recorded, transcribed, and analysed using framework analysis.ResultsPatients and clinicians felt that CRP-POCT was useful in guiding clinicians’ antibiotic prescribing decisions for AECOPD, and were positive about introduction of the test in routine care. The CRP-POCT enhanced clinician confidence in antibiotic prescribing decisions, reduced decisional ambiguity, and facilitated communication with patients. Some clinicians thought the CRP-POCT should be routinely used in consultations for AECOPD; others favoured use only when there was decisional uncertainty. CRP-POCT cartridge preparation time and cost were potential barriers to implementation.ConclusionCRP-POCT-guided antibiotic prescribing for AECOPD had high acceptability, but commissioning arrangements and further simplification of the CRP-POCT need attention to facilitate implementation in routine practice.