Diagnosing and assessing infection in general practice: Clairvoyance or EBM The example of Lower Res

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Diagnosing and assessing infection in general
practiceClairvoyance or EBM? The example of
Lower Respiratory Tract Infection

• Christopher C Butler
• Department of General Practice
• Centre for Health Sciences Research
• Cardiff University, UK

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Primary care

• 80 of all antibiotics
• 80 respiratory tract indications
• gt50 still probably unnecessary
• Cough probably the commonest acute single reason
  for consulting (130 per 1000 patients per year)

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LRTI and Pneumonia The needle in the haystack

• Hospital doctor sees one case of pneumonia
  referred by GP
• GP admits one case but has seen
• 5 cases of pneumonia
• 100 cases of bronchitis/ chest infection
• 400 cases of cough/chesty cold
• 1000-1600 adults with annoying coughs

Macfarlane
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Your context

• You are a general medical practitioner (GP) in
  Blaenau Gwent in South Wales
• Former coal mining area
• SMR125 (Hampshire and Isle of Wight92)
• of population of working age claiming a key
  social security benefit29.6

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The case

• 65 year old woman
• Usually coughs a bit but cough now worse for two
  weeks. Says, I cant shift it doctor, I have
  tried cough mixture from the chemist, I think I
  need some antibiotics now.
• Smoker
• No fever, no tachypnoea
• No wheeze but scattered crackles

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What do you do?
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Search the evidence! PICO

• Problem cough 2 weeks in a 65 year old heavy
  smoker in primary care in Blaenau Gwent
• Intervention Antibiotics, investigate, refer
• Comparison No antibiotics, no investigation
• Outcome
• Recovery?
• Pneumonia?
• Bacterial infection (etiology)?

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Search strategy

• Clinical predictors
• Symptoms
• Signs
• Clinical features
• Diagnosis
• Primary care
• General practice
• Community
• Lower respiratory tract infection
• Pneumonia
• Acute bronchitis
• Cough with sputum
• Predictors of outcome
• RTIs/di
• RTIs/ra

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Antibiotics Vs No antibiotics
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Stott and West 1976 Llanedeyrn and Fairwater
Health Centres (with thanks to AL Cochrane for
comments and criticisms)

• 210 adults with cough and purulent sputum
• Doxycycline or placebo for 10 days
• Cough, feeling off colour time of work no
  difference
• Otherwise health adults recover as quickly
  without antibiotic treatment

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Antibiotics for acute bronchitis Fahey T,
Smucny J, Becker L, Glazier RT Cochrane 2004

• 9 Trials variable quality 750 patients
• Ab treated patients
• Shorter cough duration, sputum and feeling ill
  (all by ½ day)
• At FU, less likely not to have improved by
  physicians assessment (NNT14)
• No difference in activity limitation duration
• More adverse effects (NNH17)
• Modest benefit Potential side effects

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Information leaflet and antibiotic prescribing
strategies for acute LRTI Little P. JAMA
20052933029-3035

• 807 patients with acute uncomplicated LRTI
• 262Immediate antibiotics
• 272delayed prescription
• 273no offer of antibiotics
• Cough duration same

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But what of my patient?

• Does this evidence apply to my patient?
• What examination/NPT can I do to
• rule out pneumonia?
• rule out bacterial infection?
• predict quicker recovery?

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1. Pneumonia on X-ray (RP)
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Issues

• In pre-antibiotic era, 20 mortality, patient
  dependent
• Hopstaken 4 patients with RP not treated with
  antibiotics recovered fully
• Macfarlane 316 patients in general
  practice-intensively studied
• 137 bacterial 25 RP
• 179 viral/no pathogen 10 RP
• Outcome not related to antibiotics
• 53 with bacterial or atypical infection did not
  receive antibiotics

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2.Bacterial/etiological agent
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3. Clinical recovery
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The case

• 65 year old woman
• Usually coughs a bit but cough now worse for two
  weeks. Says, I cant shift it doctor, I have
  tried cough mixture from the chemist, I think I
  need some antibiotics now.
• Smoker
• No fever, no tachypnoea
• No wheeze but scattered crackles

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A rare outcome

• There was a case a year ago, I went to see
  somebody at home who had a cough and actually
  developing chest infection. I couldnt hear
  anything on the chest and normal temperature,
  normal obs. And I said well I think its probably
  viral, just give it a bit longer and she did not
  contact us again and she was actually admitted to
  hospital, died of pneumonia. And I felt awful
  about that I keep playing it through my head
  did I do the right thing? And I think, well, by
  the book I did and I did a careful examination
  and but medical/legal things do impinge on your
  mind and I suppose that does push you a little
  bit more towards prescribing more.

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From clairvoyance to EBM

• A lot has already been achieved, given the
  paucity of evidence
• Better feasible diagnostics and predictive tools
• Hospitals and GPs to work together
• Large diagnostic and treatment studies which
  subgroups will benefit?
• Translation of evidence into practice
• Feasible
• Communication how do you implement the evidence?
• Social processes what is acceptable risk for
  patients and clinicians? Systematic study of
  patients beliefs and wants

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Uncertainty will always be with us

• It seems that, until further notice, uncertainty
  about differentiating between acute bronchitis
  and pneumonia must be accepted in daily practice
  Theo Verheij BJGP 2001
• The more complicated the world becomes, the more
  the GP will be needed. The future of general
  practice a statement by the Royal College of GPs
  September 2004

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