[Clinical characteristics of critically ill patients based on early activity dose subtypes: a cluster analysis]

To identify potential subtypes of critically ill patients based on early activity-related indicators and compare the differences in activity characteristics and clinical characteristics among different subtypes.

A prospective observational study was conducted using convenience sampling. Critically ill patients who received early mobilization in the intensive care units (ICUs) of Peking Union Medical College Hospital and Beijing Chaoyang Hospital from December 2021 to August 2023 were enrolled. General information, disease-related data, and laboratory indicators were obtained from electronic medical records. The first early mobilization session was defined as the starting point, and the last early mobilization session before ICU discharge was defined as the endpoint. Activity type, duration, and participation level were collected using the Early Mobilization Record Form for Critically Ill Patients to calculate activity dose indicators. Activity dose, activity duration, activity participation, and activity type were used as clustering variables. A two-step clustering method followed by K-means clustering analysis was performed.

A total of 149 critically ill patients who received early activity were included, and were stably classified into three potential subtypes, namely the high activity dose group (Class I, 65 cases), the moderate activity dose group (Class II, 44 cases), and the low activity dose group (Class III, 40 cases). There were statistically significant differences in activity dose, activity duration, activity participation, and activity type among the three types of patients. Among them, the high activity dose group had higher activity dose, activity duration, activity participation, and activity type, showing more positive early activity behavior. The moderate activity dose group was at a moderate level in terms of activity dose and duration, but has lower activity participation. The low activity dose group showed lower levels of activity dose, activity duration, activity participation, and activity type, characterized by insufficient activity exposure and limited activity participation. Regarding clinical characteristics, significant differences were observed among the three classes in primary disease type, proportion of surgical treatment, duration of mechanical ventilation, pain score, and muscle strength score (all P<0.05). Specifically, respiratory diseases were the predominant primary disease type in Classes I and II [46% (30/65) and 52% (23/44), respectively], whereas other disease categories accounted for a higher proportion in Class III [42% (17/40)]. Class II patients had the highest proportion of surgical treatment [82% (36/44)] and the longest duration of mechanical ventilation [118.50 (49.00, 192.00) hours]. Class III patients had the highest pain scores [2.0 (1.0, 4.0) points], whereas Class I patients had the highest muscle strength scores [53.0 (48.0, 60.0) points] and Class III patients had the lowest muscle strength scores [42.0 (34.5, 48.0) points].

Critically ill patients undergoing early mobilization can be classified into three potential subtypes (high, moderate, and low activity dose groups) based on activity dose-related indicators. Different subtypes demonstrate heterogeneity in clinical characteristics, including disease type, surgical treatment status, duration of mechanical ventilation, pain level, and muscle strength status. Clinical attention should be paid to factors such as activity participation, activity type, pain, muscle strength, and duration of mechanical ventilation, and early activity management should be carried out in a stratified and individualized manner.