ObjectiveTo evaluate how the distribution of patients in groups (based on subjective health experience) changes over time and to investigate differences in physical functioning and mental health between these patient groups. DesignAn observational cohort study. SettingUniversity medical center. ParticipantsPatients who underwent gastrointestinal or bladder oncological surgery (N=98). InterventionsNot applicable. Main Outcome MeasuresThe classification of patients into different groups based on the subjective health experience model (acceptance and perceived control), preoperatively and 1 and 3 months after discharge. ResultsIn total, 98 patients were included. Preoperatively, 31% of the patients were classified as having low acceptance and perceived control (group 4), and this proportion increased to 47% and 45% 1 and 3 months after discharge, respectively. These patients had significantly lower levels of physical functioning (preoperatively, 55 vs 61; P=.030; 1 month, 47 vs 57; P=.002; 3 months, 52 vs 62; P=.006) and higher levels of anxiety and depression (preoperatively, 14 vs 9; P<.001; 1 month, 11 vs 3; P=.001; 3 months, 10 vs 3; P=.009) than patients with high acceptance and perceived control (group 1). ConclusionsThe classification of patients to different groups provides insight in different levels of physical and mental health. However, frequent evaluation is important because of changes in patient groups over time.