Study participants
We retrospectively included consecutive patients with spontaneous ICH who were admitted to Jingjiang People’s Hospital and Zhoukou Central Hospital between January 2015 and August 2018. These two hospitals are the largest tertiary hospitals in the region and are responsible for the treatment of critical illnesses in the area. This study retrospectively included ICH patients admitted to the neurology department who did not undergo surgery. The inclusion criteria were patients who 1) were aged ≥18 years; 2) were hospitalized with the primary diagnosis of spontaneous ICH according to the World Health Organization criteria[16]; 3) were confirmed to have ICH by head computed tomography; and 4) did not undergo any surgical procedures to treat or reduce the hematoma, including but not limited to minimally invasive hematoma aspiration and craniotomy hematoma removal. The exclusion criteria were patients who acquired pneumonia before admission and patients with primary intraventricular hemorrhage.
Data collection and variable definitions
Each center selected two senior neurologic physicians to collect the information on the included cases. Cases with discrepancies in the data were evaluated by a third senior physician until an agreement was reached. We collected the patients’ demographic and clinical characteristics upon admission, including demographic data (age and sex), risk factors (history of smoking and drinking, history of chronic obstructive pulmonary disease (COPD), hypertension, hyperlipidemia, diabetes, coronary heart disease, atrial fibrillation (AF), heart failure (HF), peripheral vascular disease (PVD) and history of stroke or transient ischemic attacks (TIAs)), laboratory examination results (diastolic blood pressure and systolic blood pressure), the international normalized ratio (INR), serum creatinine levels, fasting blood glucose levels, total cholesterol levels, triglyceride levels, low-density lipoprotein cholesterol levels, high-density lipoprotein cholesterol levels and glycosylated hemoglobin levels, and the ICH-ASP-A scale and Braden scale scores at admission.
ICH-ASP-A scale was measured at admission, including items on age, current smoking status, excess alcohol consumption, COPD, prestroke level of dependence (modified Rankin Scale (mRS≥3)), Glasgow coma scale (GCS) score at admission, National Institutes of Health Stroke Scale (NIHSS) score at admission, dysphagia, the infratentorial location and extent of ventricle involvement (Table 1[11]). The total score ranges from 0-23, with a lower score being associated with a lower risk.
Nurses administered the Braden scale at 24h after admission, which is composed of six subscales: sensory perception, skin moisture, activity, mobility, nutrition, friction and shear forces. The score for friction and shear forces ranges from 1 (worst) to 3 (best), and the other scores range from 1 to 4. The sum of the scores ranges from 6 to 23 (Table 2 [17]).
Pneumonia after ICH was diagnosed according to the Centers for Disease Control and Prevention criteria[18] for hospital-acquired pneumonia on the basis of clinical and laboratory indexes of respiratory tract infection (fever, productive cough with purulent sputum, auscultatory respiratory crackles, bronchial breathing, or positive sputum culture) and supported by abnormal chest radiographic findings.
Statistical analysis
Statistical differences between the pneumonia and no pneumonia groups were performed using SPSS version 21.0 (SPSS Inc., Chicago, IL, USA). Student’s t test was used for normally distributed variables (described as the mean±SD), the Mann-Whitney U test was used for nonnormally distributed continuous variables, and Fisher’s exact test or the chi-square test was used for dichotomous variables. A P-value of < 0.05 was considered statistically significant. Then, receiver operating characteristic (ROC) curve analysis was performed to investigate the predictive validity of the Braden scale for pneumonia after ICH. An area under the curve (AUC) of 0.97–1.00 indicates excellent accuracy; 0.93 to 0.96 indicates very good accuracy; and 0.75 to 0.92 indicates good accuracy. However, an AUC of < 0.75 indicates obvious deficiencies, and an AUC of 0.5 indicates that the test has no predictive ability[19].