DRIP Score

Why use it

Outperforms HCAP criteria for predicting drug-resistant organisms in community-onset pneumonia. Reduces unnecessary broad-spectrum antibiotic use in low-risk patients. Validated prospectively with sensitivity 82% and specificity 74% for DRP at a threshold of ≥ 4.

About

The Drug Resistance in Pneumonia (DRIP) score identifies patients with community-onset pneumonia who harbor drug-resistant pathogens (DRP) — including MRSA, drug-resistant Streptococcus pneumoniae, and Pseudomonas aeruginosa — and who therefore require broad-spectrum empiric antibiotic coverage. It was developed to replace the older healthcare-associated pneumonia (HCAP) criteria, which had poor specificity and led to widespread antibiotic overuse. The DRIP score uses two major criteria (+2 each) and five minor criteria (+1 each). A score ≥ 4 identifies high-risk patients. Developed by Webb et al. (Chest 2016) from a multi-center retrospective cohort of 1,474 patients and validated prospectively.

When to use

• Community-onset pneumonia requiring empiric antibiotic selection
• Deciding whether to add MRSA coverage (vancomycin, linezolid) to empiric regimen
• Deciding whether to add anti-pseudomonal coverage (piperacillin-tazobactam, cefepime, meropenem) to empiric regimen
• Replacing HCAP criteria for DRP risk stratification
• ED or hospital admission for pneumonia with unknown causative organism

Formula

Pearls & pitfalls

• DRIP ≥ 4 has sensitivity ~82% and specificity ~74% for drug-resistant pathogens (better than HCAP criteria).
• Prior antibiotic use in past 30 days is the most important single variable (+2) — obtain accurate antibiotic history.
• Tube feeding is a major criteria (+2) because it is associated with colonization with gram-negative organisms and aspiration of pharyngeal flora.
• DRIP score does NOT replace microbiological cultures — always obtain cultures in moderate-to-severe pneumonia.
• The HCAP concept (hospitalization, HD, nursing home, home infusion) has been abandoned by most guidelines due to poor specificity; DRIP is the validated replacement.
• Prior MDR organism colonization/infection is also a major criterion (+2) — review microbiology records.
• Non-ambulatory functional status is associated with aspiration and healthcare contact.
• De-escalation after 48–72 hours based on culture results is critical to minimize antibiotic overuse in initially high-risk patients.

Next steps

Score 0–3 (Low risk): Standard community-acquired pneumonia coverage (beta-lactam + macrolide, or respiratory fluoroquinolone). No MRSA or anti-Pseudomonal coverage required. Score ≥ 4 (High risk): Broad-spectrum empiric coverage warranted. Add MRSA coverage (vancomycin IV or linezolid) AND anti-pseudomonal agents (piperacillin-tazobactam, cefepime, or carbapenems). Obtain blood cultures and respiratory cultures. De-escalate based on culture results within 48–72 hours.

Evidence

Webb BJ et al. Derivation and validation of a score to predict drug-resistant organisms in community-onset pneumonia. Chest. 2016;150(5):1071-1080. Prospective external validation in 200 patients showed AUC 0.81 for drug-resistant pathogens. Endorsed by ATS and IDSA 2019 CAP guidelines as an alternative to HCAP criteria.

References

1. Webb BJ et al. Derivation and validation of a score to predict drug-resistant organisms in community-onset pneumonia. Chest. 2016;150(5):1071-1080. — link
2. Metlay JP et al. Diagnosis and Treatment of Adults with Community-acquired Pneumonia. An Official ATS/IDSA Clinical Practice Guideline. Am J Respir Crit Care Med. 2019;200(7):e45-e67. — link