Point of care testsPoint of care testsPresentation 14.5.09, Presentation 14.5.09,

Nordisk kongress KøbenhavnNordisk kongress København

Morten Lindbæk, professor Morten Lindbæk, professor University of Oslo and ASPUniversity of Oslo and ASP

OutlineOutline

C-reactive proteinC-reactive protein How often usedHow often used Does CRP contribute to better diagnosis?Does CRP contribute to better diagnosis? Does CRP contribute to lower antibiotic prescription?Does CRP contribute to lower antibiotic prescription? More use in outpatient care – nursing homes?More use in outpatient care – nursing homes?

Strep-testStrep-test Future tests - Procalcitonin?Future tests - Procalcitonin? Does use of POC-testing contribute to medicalising Does use of POC-testing contribute to medicalising

self-limiting RTIs?self-limiting RTIs?

CRP – how often used?CRP – how often used?

Norway: 1.8 mill/13 mill.(14%) of all Norway: 1.8 mill/13 mill.(14%) of all consultations in primary care per year, started in consultations in primary care per year, started in 1990, reimbursed, now patient pays half.1990, reimbursed, now patient pays half.

Vestfold Winter 2003: 44% of all with RTIsVestfold Winter 2003: 44% of all with RTIs Sweden: 31%-41% of consultations with RTIs in Sweden: 31%-41% of consultations with RTIs in

general practicegeneral practice Denmark: Also extensively used.Denmark: Also extensively used. Finland: Much lower us in primary careFinland: Much lower us in primary care Holland: Little useHolland: Little use UK: no use in primary careUK: no use in primary care Switserland: moderate use in primary careSwitserland: moderate use in primary care

Does CRP contribute to better Does CRP contribute to better diagnostic work in general practicediagnostic work in general practice

LRTILRTI Van der Meer: syst review of diagnostic value: 12 studies, Van der Meer: syst review of diagnostic value: 12 studies,

heterogenous, sens 8-99%, spec 27-95% bact. infection. heterogenous, sens 8-99%, spec 27-95% bact. infection. Conclusion: Not recommended. Much discussed Conclusion: Not recommended. Much discussed

Hopstaken (Holland) demonstrated that CRP was good to single Hopstaken (Holland) demonstrated that CRP was good to single out patients with documented viral/bacterial infection, not to out patients with documented viral/bacterial infection, not to separate themseparate them

Melbye demonstrated that CRP was good to single out patients Melbye demonstrated that CRP was good to single out patients with bacterial pneumonia in primary carewith bacterial pneumonia in primary care

Acute sinusitisAcute sinusitis Jens G Hansen BMJ 1995 (Both CRP and ESR)Jens G Hansen BMJ 1995 (Both CRP and ESR) Lindbæk (CRP/ESR bivariate, only ESR multivariate analysis)Lindbæk (CRP/ESR bivariate, only ESR multivariate analysis)

Tonsillitis?Tonsillitis? Can CRP single out those Strep A patients that can profit from Can CRP single out those Strep A patients that can profit from

antibiotic treatment? Not been performed research on thisantibiotic treatment? Not been performed research on this

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

Acute sinusitis: Acute sinusitis: Bjerrum Doctors using CRP prescribed in 59%, without 78%Bjerrum Doctors using CRP prescribed in 59%, without 78% JG Hansen: RCT based on elevated CRP-level, demonstrated JG Hansen: RCT based on elevated CRP-level, demonstrated

significant less pain, but not general conditionsignificant less pain, but not general condition LRTIs: LRTIs:

Cals Dutch study (BMJ May 09). 2x2 factorial design with Cals Dutch study (BMJ May 09). 2x2 factorial design with educational outreach (27% vs 54%) and use of CRP (31% vs educational outreach (27% vs 54%) and use of CRP (31% vs 53%). Both gave significant lowering of prescription, 23% in 53%). Both gave significant lowering of prescription, 23% in combination combination

RTIs: RTIs: Lindbæk observational study CRP test contributed significantly Lindbæk observational study CRP test contributed significantly

to 30% of patients with infections. CRP contributed to reduction to 30% of patients with infections. CRP contributed to reduction of antibiotics in 25% of antibiotics in 25%

Other use of CRP-test in Other use of CRP-test in outpatient careoutpatient care

The use in nursing homes in Norway is The use in nursing homes in Norway is increasing. Can contribute to better increasing. Can contribute to better diagnosing of RTI’s. Especially combined diagnosing of RTI’s. Especially combined with more use of intravenous antibioticswith more use of intravenous antibiotics

Also more use in homebased care by Also more use in homebased care by nursesnurses

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

Sensitivity 90%, specificity 95%, LR+ 16Sensitivity 90%, specificity 95%, LR+ 16 Combination of Centor criteria (4) and Combination of Centor criteria (4) and

testing gives most certain diagnosis testing gives most certain diagnosis But high rate of healthy carriers, especially But high rate of healthy carriers, especially

among children and adolescents in among children and adolescents in summer, 20-30 % (Ronny Gunnarson)summer, 20-30 % (Ronny Gunnarson)

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

No significant results from primary care, No significant results from primary care, one smaller Danish study showed no one smaller Danish study showed no reduction (Andersen et al BMJ 1995)reduction (Andersen et al BMJ 1995)

Some studies from specialist care, Some studies from specialist care, pediatricians in Greecepediatricians in Greece

New promising POC-test:Maybe New promising POC-test:Maybe procalcitonin?procalcitonin?

METHODS: 53 Swiss primary care physicians recruited METHODS: 53 Swiss primary care physicians recruited 458 patients, each patient with an acute respiratory tract 458 patients, each patient with an acute respiratory tract infection and, in the physician's opinion, in need of infection and, in the physician's opinion, in need of antibiotics. Results after 2-4 hours from hospitalantibiotics. Results after 2-4 hours from hospital

RCT: For patients randomized to procalcitonin-guided RCT: For patients randomized to procalcitonin-guided therapy or standard, the use of antibiotics was more or therapy or standard, the use of antibiotics was more or less strongly discouraged or recommended (cut-off less strongly discouraged or recommended (cut-off >0.25 microg/L). >0.25 microg/L).

RESULTS: With procalcitonin-guided therapy, the RESULTS: With procalcitonin-guided therapy, the antibiotic prescription rate was 72% lower (95% CI, 66%-antibiotic prescription rate was 72% lower (95% CI, 66%-78%) than with standard therapy. Both approaches led to 78%) than with standard therapy. Both approaches led to a similar proportion of patients reporting symptoms of a similar proportion of patients reporting symptoms of ongoing or relapsing infection at 28 days (adjusted odds ongoing or relapsing infection at 28 days (adjusted odds ratio, 1.0 [95% CI, 0.7-1.5]). ratio, 1.0 [95% CI, 0.7-1.5]).

Medicalising effect of POC-testing?Medicalising effect of POC-testing?

Malin Andre: Question the use of CRP, 42% of Malin Andre: Question the use of CRP, 42% of all with RTI had a test performed.all with RTI had a test performed. Often used in URTI where the agent often is viral and Often used in URTI where the agent often is viral and

the consequence is doubtful. Small reduction in ab us the consequence is doubtful. Small reduction in ab us (44% vs 41%). Danger of medicalisation(44% vs 41%). Danger of medicalisation

Will use of POC-testing lead to: Patients/parents Will use of POC-testing lead to: Patients/parents go to doctor just to be sure?go to doctor just to be sure?

””Table catching”: When you have taken a strep Table catching”: When you have taken a strep A, positive, it is harder to avoid giving antibiotics, A, positive, it is harder to avoid giving antibiotics, even if the patient is feeling pretty welleven if the patient is feeling pretty well

Should GPs be more critical in when to use Should GPs be more critical in when to use POC-tests. Reimbursement?POC-tests. Reimbursement?