Point of care tests Presentation 14.5.09, Nordisk kongress K

1
Point of care testsPresentation 14.5.09,
Nordisk kongress KøbenhavnMorten Lindbæk,
professor University of Oslo and ASP
2
Outline

• C-reactive protein
• How often used
• Does CRP contribute to better diagnosis?
• Does CRP contribute to lower antibiotic
  prescription?
• More use in outpatient care nursing homes?
• Strep-test
• Future tests - Procalcitonin?
• Does use of POC-testing contribute to
  medicalising self-limiting RTIs?

3
CRP how often used?

• Norway 1.8 mill/13 mill.(14) of all
  consultations in primary care per year, started
  in 1990, reimbursed, now patient pays half.
• Vestfold Winter 2003 44 of all with RTIs
• Sweden 31-41 of consultations with RTIs in
  general practice
• Denmark Also extensively used.
• Finland Much lower us in primary care
• Holland Little use
• UK no use in primary care
• Switserland moderate use in primary care

4
Does CRP contribute to better diagnostic work in
general practice

• LRTI
• Van der Meer syst review of diagnostic value 12
  studies, heterogenous, sens 8-99, spec 27-95
  bact. infection. Conclusion Not recommended.
  Much discussed
• Hopstaken (Holland) demonstrated that CRP was
  good to single out patients with documented
  viral/bacterial infection, not to separate them
• Melbye demonstrated that CRP was good to single
  out patients with bacterial pneumonia in primary
  care
• Acute sinusitis
• Jens G Hansen BMJ 1995 (Both CRP and ESR)
• Lindbæk (CRP/ESR bivariate, only ESR multivariate
  analysis)
• Tonsillitis?
• Can CRP single out those Strep A patients that
  can profit from antibiotic treatment? Not been
  performed research on this

5
Can use of CRP contribute to more rational
antibiotic use in RTIs?

• Acute sinusitis
• Bjerrum Doctors using CRP prescribed in 59,
  without 78
• JG Hansen RCT based on elevated CRP-level,
  demonstrated significant less pain, but not
  general condition
• LRTIs
• Cals Dutch study (BMJ May 09). 2x2 factorial
  design with educational outreach (27 vs 54) and
  use of CRP (31 vs 53). Both gave significant
  lowering of prescription, 23 in combination
• RTIs
• Lindbæk observational study CRP test contributed
  significantly to 30 of patients with infections.
  CRP contributed to reduction of antibiotics in
  25

6
Other use of CRP-test in outpatient care

• The use in nursing homes in Norway is increasing.
  Can contribute to better diagnosing of RTIs.
  Especially combined with more use of intravenous
  antibiotics
• Also more use in homebased care by nurses

7
Can use of Strep A test contribute to more exact
diagnosis?

• Sensitivity 90, specificity 95, LR 16
• Combination of Centor criteria (4) and testing
  gives most certain diagnosis
• But high rate of healthy carriers, especially
  among children and adolescents in summer, 20-30
  (Ronny Gunnarson)

8
Can use of Strep A test contribute to reduced use
of antibiotics?

• No significant results from primary care, one
  smaller Danish study showed no reduction
  (Andersen et al BMJ 1995)
• Some studies from specialist care, pediatricians
  in Greece

9
New promising POC-testMaybe procalcitonin?

• METHODS 53 Swiss primary care physicians
  recruited 458 patients, each patient with an
  acute respiratory tract infection and, in the
  physician's opinion, in need of antibiotics.
  Results after 2-4 hours from hospital
• RCT For patients randomized to
  procalcitonin-guided therapy or standard, the use
  of antibiotics was more or less strongly
  discouraged or recommended (cut-off gt0.25
  microg/L).
• RESULTS With procalcitonin-guided therapy, the
  antibiotic prescription rate was 72 lower (95
  CI, 66-78) than with standard therapy. Both
  approaches led to a similar proportion of
  patients reporting symptoms of ongoing or
  relapsing infection at 28 days (adjusted odds
  ratio, 1.0 95 CI, 0.7-1.5).

10
Medicalising effect of POC-testing?

• Malin Andre Question the use of CRP, 42 of all
  with RTI had a test performed.
• Often used in URTI where the agent often is viral
  and the consequence is doubtful. Small reduction
  in ab us (44 vs 41). Danger of medicalisation
• Will use of POC-testing lead to Patients/parents
  go to doctor just to be sure?
• Table catching When you have taken a strep A,
  positive, it is harder to avoid giving
  antibiotics, even if the patient is feeling
  pretty well
• Should GPs be more critical in when to use
  POC-tests. Reimbursement?

11
(No Transcript)