BAHNG score: predictive model for detection of subjects with the oropharynx colonized by uncommon microorganisms

Pneumonia is most frequently produced by the microaspiration of flora that colonizes the oropharynx. Etiological diagnosis of pneumonia is infrequent in clinical practise and empirical treatment should be prescribed. The aims of the present study were to determine the factors associated with oropharynx colonization by uncommon microorganisms (UM) and to develop a predictive model.

A cross-sectional study that included all pa-tients living in one long-term care facilities was developed. Demographic, comorbidities, basal functional status and clinical data were collected. To determinate the oropharyngeal colonization, a single sample of pharynx was obtained for each subject using a cotton swab.

A total of 221 subjects were included, mean age 86.27 (SD 8.05) years and 157 (71%) were female. In 32 (14.5%) subjects UM flora was isolated, Gram-negative bacilli in 16 (7.2%) residents, and Staphylococcus aureus in 16 (7.2%). The predictive model included the presence of hypertension, neuromuscular disease, Barthel <90 and use of PEG. The BAHNG score (BArthel, Hypertension, Neuromuscular, Gastrostomy), showed an area under the curve of 0.731 (CI 95% 0.643-0.820; p<0.001). We have classified patients according to this score in low (0-2 points), intermediate (3-5 points) and high risk (≥ 6). The probability of UM colonization in the oropharyngeal based on this classification is 4.1%, 15.8% and 57.1% for low, intermediate and high risk, respectively.

The BAHNG score could help in the identifications of elderly patients with high risk of colonization by UM. In case of pneumonia the evaluation of the subject through this score could help in the initial decisions concerning antibiotic treatment.