NICE vs BTS: Management of Community-Acquired Pneumonia (2025)
Community-acquired pneumonia (CAP) is a significant cause of morbidity and mortality in the UK. For clinicians, two key national guidelines inform management: the National Institute for Health and Care Excellence (NICE) Clinical Guideline (CG191) and the British Thoracic Society (BTS) Guidelines. While aligned on core principles, they differ in several practical aspects, from severity assessment to antibiotic choice. This comparison distills the 2025-relevant recommendations from both, highlighting key differences and practical takeaways for UK clinical practice.
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Diagnosis and Initial Assessment
NICE (CG191)
NICE recommends considering a diagnosis of pneumonia in patients presenting with symptoms and signs, and confirms it with a chest X-ray. Key to the NICE pathway is the use of the CURB-65 score for severity assessment:
- Score 0-1: Consider home-based treatment.
- Score 2: Consider hospital-assisted treatment.
- Score 3 or more: Manage as severe pneumonia, considering ICU assessment.
NICE also recommends CRP testing to help distinguish between bacterial and viral pneumonia if the diagnosis is unclear, and to guide antibiotic review (e.g., stopping antibiotics if CRP is <20 mg/L after initial assessment).
BTS Guidelines
BTS also strongly advocates for a chest X-ray to confirm diagnosis. For severity assessment, BTS recommends the CURB-65 score but places greater emphasis on clinical judgement alongside the score. BTS highlights specific clinical factors that should prompt hospital admission regardless of CURB-65, such as significant hypoxia (SaO2 <92%), haemodynamic instability, or social factors. BTS does not routinely recommend CRP for diagnosis but acknowledges its utility in monitoring response to treatment.
Key Difference
The primary difference lies in the role of CRP. NICE provides a more defined role for CRP in both initial diagnosis and stewardship (stopping antibiotics), whereas BTS relies more heavily on clinical and radiological findings.
Antimicrobial Treatment
NICE (CG191)
NICE recommendations are stratified by severity assessed via CURB-65:
- Low severity (CURB-65 0-1): First-line is Amoxicillin orally. A macrolide (e.g., Clarithromycin) is added only if atypical pathogens are suspected or in epidemics.
- Moderate severity (CURB-65 2): First-line is Co-amoxiclav OR a cephalosporin (e.g., Ceftriaxone) IV + a macrolide (e.g., Clarithromycin) orally.
- High severity (CURB-65 3+): Co-amoxiclav IV + a macrolide (e.g., Clarithromycin) IV.
NICE advises a 5-day course of antibiotics, reviewing at this point based on clinical response.
BTS Guidelines
BTS treatment stratification is based on whether treatment is community or hospital-based, with a stronger focus on local antibiotic resistance patterns (particularly penicillin-resistant Streptococcus pneumoniae):
- Community Treatment: Amoxicillin is first-line. A macrolide is recommended as first-line dual therapy only in areas with high incidence of penicillin resistance, or if atypicals are suspected.
- Hospital Treatment (Non-Severe): Benzylpenicillin IV OR Amoxicillin oral/IV is preferred. A macrolide is added if atypicals are suspected or the patient is severely ill.
- Hospital Treatment (Severe): A beta-lactamase stable beta-lactam (e.g., Co-amoxiclav or Cefuroxime) IV + a macrolide IV.
BTS recommends a 7-day course as standard, extending if the response is slow.
Key Differences
- First-line Antibiotic: For hospitalised patients, NICE favours Co-amoxiclav or a cephalosporin, while BTS prefers Benzylpenicillin or Amoxicillin where possible, reserving broader-spectrum agents for more severe cases or resistance concerns.
- Treatment Duration: NICE recommends a 5-day course; BTS recommends a 7-day course.
- Macrolide Use: BTS is more conservative with macrolide use, typically reserving it for specific indications, whereas NICE recommends it more readily for moderate and high-severity cases.
Special Situations and Patient Groups
Penicillin Allergy
NICE: For non-severe allergy, recommends a cephalosporin (e.g., Cefalexin). For severe allergy, recommends a macrolide (e.g., Clarithromycin) or tetracycline (e.g., Doxycycline).
BTS: For non-severe allergy, recommends a cephalosporin. For severe IgE-mediated allergy, recommends a respiratory quinolone (e.g., Levofloxacin) as monotherapy, avoiding cephalosporins entirely.
Pneumonia in the Elderly or Frail
Both guidelines stress that typical symptoms (fever, cough) may be absent. BTS provides more detailed guidance on this, emphasising non-specific presentations like functional decline, and the importance of a low threshold for chest X-ray and admission.
Pneumonia in Pregnancy
Both guidelines recommend a low threshold for admission. NICE specifies that a macrolide (Clarithromycin or Erythromycin) is suitable. BTS provides more comprehensive advice, including avoiding tetracyclines and quinolones, and discussing the benefits/risks of Co-amoxiclav.
Practical Clinical Flow and Takeaway
A pragmatic synthesis for hospital clinicians in 2025 might look like this:
- Suspect CAP based on clinical presentation (cough, fever, dyspnoea, signs on examination).
- Confirm with Chest X-ray (per both guidelines).
- Assess Severity: Calculate CURB-65 but augment with clinical judgement (per BTS), especially regarding hypoxia and comorbidities.
- Initiate Antibiotics Promptly:
- For most non-severe hospitalised patients: Consider local policy. A pragmatic choice is Amoxicillin IV/oral (BTS-leaning) or Co-amoxiclav IV (NICE-leaning), adding a macrolide only if indicated.
- For severe CAP (CURB-65 ≥3, septic shock, hypoxia): Use IV Co-amoxiclav + IV Macrolide (aligns with both).
- Stewardship & Review:
- Consider CRP at baseline and after 48-72 hours to guide therapy (NICE approach).
- Switch to oral therapy when improving.
- Plan for a 5-7 day total duration, individualising based on response.
Frequently Asked Questions (FAQs)
1. Which guideline should I follow in my NHS Trust?
Most NHS Trusts have a local antibiotic guideline or CAP policy that synthesises recommendations from NICE and BTS, often considering local resistance patterns. Your local policy is the primary document you should follow. In the absence of a local policy, using a blended approach (e.g., BTS for diagnosis/admission, NICE for antibiotic review with CRP) is common.
2. Is CURB-65 sufficient for deciding on ICU admission?
No. Both guidelines state that CURB-65 is a starting point. Clinical judgement is paramount. Signs of severe sepsis or septic shock, persistent hypoxia despite oxygen, or a high respiratory rate are more direct indicators for critical care referral.
3. Why does BTS prefer Benzylpenicillin over Co-amoxiclav for non-severe cases?
This is primarily for antimicrobial stewardship. Benzylpenicillin has a narrower spectrum, effectively covering the most common pathogen (Streptococcus pneumoniae) while reducing the risk of Clostridium difficile and antibiotic resistance. Co-amoxiclav is reserved for cases where broader coverage is needed.
4. How should I manage a patient with a true, severe penicillin allergy?
This is a key difference. BTS advice is more cautious, recommending a respiratory quinolone (e.g., Levofloxacin) to avoid any beta-lactam cross-reactivity. NICE suggests a macrolide or tetracycline. Given the risks, the BTS approach is often favoured in hospital practice for severe allergies.
5. What is the role of procalcitonin in CAP in the UK?
Neither NICE nor BTS currently recommends the routine use of procalcitonin to guide antibiotic initiation or duration in CAP within the NHS. CRP remains the preferred biomarker where used.
Source Links
- NICE Guideline CG191 (Pneumonia): [https://www.nice.org.uk/guidance/cg191]
- BTS Guidelines for Community-Acquired Pneumonia in Adults (2009, updated 2015): [https://www.brit-thoracic.org.uk/quality-improvement/guidelines/cap/] (Note: While the BTS guideline is older, it remains the current standard in UK practice, with updates expected to align with these core principles.)