Objectives To develop hypotheses about whether there are patient-related factors that influence physicians' decision-making that can explain why some patients with severe subjective health complaints (SHCs) are more likely to be granted sick leave than others. Design Exploratory cross-sectional. Setting Assessments of patient-related factors after watching nine authentic video recordings of patients with severe SHC from a Norwegian general practice. Our previous study showed that three of these nine patients were less likely than the remaining six patients to be granted sick leave by physicians from five European countries. Participants In total, 10 assessors from Norway, the Netherlands and France. Outcomes The direction in which the assessments may contribute towards the decision to grant a sickness certificate (increasing or decreasing the likelihood of granting sick leave). Results Physicians consider a wide variety of patient-related factors when assessing sickness certification. The overall assessment of these factors may provide an indication of whether a patient is more likely or less likely to be granted sick leave. Additionally, some single questions (notable functional limitations in the consultation, visible suffering, a clear purpose for sick leave and psychiatric comorbidity) may indicate differences between the two patient groups. Conclusions Next to the overall assessment, no notable effect of the complaints on functioning and suffering, a lack of a clear purpose for sick leave and the absence of psychiatric comorbidity may be factors that could help guide the decision to grant sick leave. These hypotheses should be tested and validated in representative samples of professionals involved in sickness certification. This may help to understand the tacit knowledge we believe physicians have when assessing work capacity of patients with severe SHC.