[C-reactive protein and infections in general practice]. / C-reaktivt protein og infektioner i almen praksis.

C-reactive protein (CRP) is a sensitive and non-specific inflammatory marker. The serum level of CRP starts to rise 6-12 hours after the start of an inflammatory stimulus. Sequential CRP measurements will have greater diagnostic value than a single measurement, and changes of the CRP values often reflect the clinical course. In use in general practice the diagnostic value of CRP is found to be high in adults with pneumonia, sinusitis and tonsillitis, however it is found to be low regarding otitis and pneumonia in children. As to urinary tract infections and salpingitis the value is still undefined. Measurement of CRP is an important diagnostic test but the analysis should not stand by itself but be evaluated together with the patient's history and clinical examination.

Evaluation of a simple dosage scheme for transition from phenprocoumon to warfarin in oral anticoagulation.

Phenprocoumon, whose elimination half-time is 144 hours, has been the traditional oral anticoagulant of choice in Europe. However, today's most widely used drug is warfarin, whose elimination half-time is 40 hours. This study aims to evaluate a method for safe transition from phenprocoumon to warfarin, which is sometimes required. Hence, the large difference in their elimination rates may on occasion lead to serious overdosage upon transition from one drug to the other. According to average equipotent doses, a stepwise increase in warfarin dose was calculated based on the elimination half-times of the two drugs. The dosage scheme was subsequently tested in a pilot study including 35 patients. The conversion scheme was then adjusted based on the results from the pilot study. The new scheme was tested in 69 patients. The transition factor was 2.3, which implies that equipotency was achieved when the warfarin dose was 2.3 times larger than the phenprocoumon dose (in mg). This scheme proved optimal for 75% of the patients. However, the dose had to be adjusted individually in the remaining 25% of the patients to a level corresponding to the measured international normalised ratios. No patients experienced haemorrhages or thromboembolic complications during the period of changeover. In conclusion, the proposed scheme for changing medication from phenprocoumon to warfarin is safe and convenient.

Near-patient test for C-reactive protein in general practice: assessment of clinical, organizational, and economic outcomes.

BACKGROUND: The benefits of near-patient, point-of-care tests have not been fully examined. We have assessed the clinical, organizational, and economic outcomes of implementing a near-patient test for C-reactive protein (CRP) in general practice. METHODS: In a randomized crossover trial during intervention periods, general practitioners (GPs) were allowed to measure CRP within 3 min, using NycoCard(R) CRP. During control periods, they had to mail blood samples for CRP measurements to the hospital laboratory and received test results 24-48 h later. Twenty-nine general practice clinics participated (64 GPs), and 1853 patients were included in the study. Results were evaluated at both the level of participating GPs and the level of included patients. RESULTS: For participating GPs, the overall use of erythrocyte sedimentation rates (ESRs) decreased by 8% (95% confidence interval, 1-14%) during intervention periods, and the number of blood samples mailed to the hospital laboratory decreased by 6% (1-10%). No reduction in the prescription of antibiotics was seen. The proportion of study patients having a follow-up telephone consultation was reduced from 63% to 53% (P = 0. 0001), and patients with CRP concentrations >50 mg/L had their antibiotic treatments started earlier when CRP was measured in general practices (P = 0.0161). CONCLUSION: The implementation of the near-patient CRP test was cost-effective mainly on the basis of a reduction in the use of services from the hospital laboratory by GPs. If the implementation is followed by education and clinical guidelines, opportunities exist for additional reduction in the use of ESR and for a more appropriate use of antibiotics.

Effect of anticoagulant therapy on the hypercoagulable state in patients carrying the factor V Arg506Gln mutation.

Resistance to activated protein C, caused by a single point mutation in the factor V gene (Arg506Gln or FV Leiden), is the most prevalent single risk factor associated with venous thromboembolic disease. The aim of this study was to investigate the effectiveness of standard oral anticoagulant therapy (OAT) in patients with the Arg506Gln mutation compared with a matched control group. The study compared selected variables in 27 patients carrying the Arg506Gln mutation with 27 sex- and age-matched controls in steady state oral anticoagulant treatment (OAT). The study showed that similar doses of vitamin K antagonists in carriers and noncarriers suppress and generate a uniform distribution of coagulation markers in steady state OAT. Thus, it seems that OAT with standard treatment doses is just as effective in patients with the Arg506Gln mutation as in comparable controls without the mutation.

[Diagnostic value of C-reactive protein in bacterial infections. Review of the literature]. / Diagnostisk vaerdi af C-reaktivt protein ved bakterielle infektioner. En litteraturoversigt.

Conflicting data for predictive values for C-reactive protein (CRP) in its ability to distinguish between viral and bacterial diseases are reviewed. Study designs regarding setting, patient-mix, severity of disease and prevalence seem to determine the magnitude of predictive values. We have calculated predictive values for patients suspected of septicaemia, meningitis, appendicitis, cholecystitis, upper- and lower respiratory disease, acute sinusitis and acute otitis media, and revealed the highest predictive values among patients suspected for severe and generalized infections. More localized diseases have lower predictive values. We emphasize the importance of a study design where the circumstances resemble the real situations in which the test is supposed to be used. This will ensure the clinical applicability of predictive values for a diagnostic test.

[Differences in the use of C-reactive protein analysis and erythrocyte sedimentation in general practice and hospitals. Development from 1986 to 1995]. / Forskelle i brugen af C-reaktivt protein og saenkningsreaktion i almen praksis og på sygehus. Udvikling fra 1986 til 1995.

Analysis for C-reactive protein (CRP) was introduced in the Vejle Hospital catchment area in 1987. During the next ten year period the use of CRP has increased to reach a stable level both on hospital wards, out-patient clinics and in general practice. While the use of erythrocyte sedimentation rate on wards has decreased correspondingly, this is not seen in out-patient clinics or in general practice. There are medical as well as practical reasons for this discrepancy. It is believed that the possibility of performing a CRP as a point-of-care test in the GPs office in the future will lead to a reduction in the number of analyses of erythrocyte sedimentation rate performed in general practice as well.

[Is the randomized controlled trial overvalued as a basis for clinical decision-making? A review with comments]. / Er det randomiserede forsøg overvurderet som klinisk beslutningsgrundlag? En Kommenteret oversigt.

The randomized controlled trial (RCT) may have considerable limitations in clinical research. Lacking the possibility of blinding impairs the internal validity of the trials. The external validity is often impaired, as results of RCTs obtained in an ideal situation, may be difficult to generalize to a clinical routine situation. Pragmatic randomized trials move from ideal situations towards routine situations, and by modifying the design it is possible to reduce selection bias due to patient and physician preferences. Quasi-experimental studies have varying degrees of problems with internal validity but are necessary contributions to our knowledge of the effect of treatment in clinical routine situations. Limitations of the usefulness of RCTs as well as pragmatic and quasi-experimental studies in clinical research make it necessary to recognise that different methods complement one another. Research in development of RCTs and new methods in clinical research should be encouraged.

Evaluation of a near-patient test for C-reactive protein used in daily routine in primary healthcare by use of difference plots.

We have assessed the technical performance and robustness of NycoCard CRP Whole Blood, a near-patient test for C-reactive protein (CRP), when used in realistic daily routine situations in general practice clinics (GPC). Thirteen GPCs participated, five of them with technician staff. From 898 patients, split-sample measurements for CRP were made. Results from GPCs were compared with results from a turbidimetric laboratory method, traceable to international reference preparations (IFCC CRM 470). Results were evaluated in difference plots where the expected distribution, due to an estimated analytical variation, was compared with measured differences. Of all difference points, 91.5% (n = 819) were within a 95% prediction interval based on the imprecision of both methods. Mean bias (95% confidence interval) was -0.3 mg/L (-0.9 to 0.3). No differences in analytic quality were found between GPCs with technician staffs and GPCs without, and between test results obtained within the first and second week, compared with the rest of the study period. We find the test as good when used in GPCs as could be expected from laboratory testing, and consequently robust, which is a necessity for use in routine situations in general practice. General application of difference plots in test evaluations are discussed in detail.

C-reactive protein in general practice--how commonly is it used and why?

OBJECTIVE: C-reactive protein (CRP) is a well-known diagnostic tool in general practice. The scope of this study was to assess how frequently CRP is used by general practitioners and to evaluate the reasons for using it. DESIGN: A retrospective part based on data from a laboratory database system, and a prospective part with a questionnaire-based registration. SETTING: 30 general practice clinics in the catchment area of Vejle County Central Hospital. SUBJECTS: Retrospectively, all patients from general practice serviced by the laboratory for one year. Prospectively, 1190 patients from whom a blood sample was taken for CRP-measurement during a 2 month study period. MAIN OUTCOME MEASURES: The frequency of using CRP and the reason requesting it; A) diagnosing a new disease, B) monitoring a well-known disease, or C) "screening". Furthermore; 1) infections, 2) chronic inflammatory disease, 3) malignant disease, or 4) others. RESULTS: CRP-measurements were ordered in 3.7% of all consultations in general practice and for 34.1% of all patients whose blood sample was analysed at the central laboratory. The use of CRP was as follows: A-1: 28.6%, A-2: 6.7%, A-3,4: 9.3%, B-1: 8.2%, B-2: 12.4%, B-3,4: 6.5%, C-1: 5.7%, C-2: 3.2%, C-3: 3.5% and C-4: 15.2%. Diagnosing a new (infectious) disease was the most frequent single reason for CRP-measurement. There was major interpractice variation. CONCLUSIONS: CRP is frequently used in general practice, mostly (65.4%) in the field of infections and chronic inflammatory diseases. Because of major interpractice variation, the most correct way of using CRP should be evaluated and guidelines should be provided.