A case study of nurse practitioner care compared with general practitioner care for children with respiratory tract infections.

AIM: To compare quality of care provided by nurse practitioners (NP) with care provided by general practitioners (GP) for children with respiratory tract infections (RTI) in the Netherlands. BACKGROUND: Nurse practitioners increasingly manage acute conditions in general practice, with opportunities for more protocolled care. Studies on quality of NPs' care for children with RTIs are limited to the US healthcare system and do not take into account baseline differences in illness severity. DESIGN: Retrospective observational cohort study. METHODS: Data were extracted from electronic healthcare records of children 0-6 years presenting with RTI between January-December 2013. Primary outcomes were antibiotic prescriptions and early return visits. Generalized estimating equations were used to correct for potential confounders. RESULTS: A total of 899 RTI consultations were assessed (168 seen by NP; 731 by GP). Baseline characteristics differed between these groups. Overall antibiotic prescription and early return visit rates were 21% and 24%, respectively. Adjusted odds ratio for antibiotic prescription after NP vs. GP delivered care was 1.40 (95% confidence interval 0.89-2.22) and for early return visits 1.53 (95% confidence interval 1.01-2.31). Important confounder for antibiotic prescription was illness severity. Presence of wheezing was a confounder for return visits. Complication and referral rates did not differ. CONCLUSION: Antibiotic prescription, complication and referral rates for paediatric RTI consultations did not differ significantly between NP and GP consultations, after correction for potential confounders. General practitioners, however, see more severely ill children and have a lower return visit rate. A randomised controlled study is needed to determine whether NP care quality is truly noninferior.

The added value of C-reactive protein measurement in diagnosing pneumonia in primary care: a meta-analysis of individual patient data.

BACKGROUND: C-reactive protein (CRP) is increasingly being included in the diagnostic work-up for community-acquired pneumonia in primary care. Its added diagnostic value beyond signs and symptoms, however, remains unclear. We conducted a meta-analysis of individual patient data to quantify the added value of CRP measurement. METHODS: We included studies of the diagnostic accuracy of CRP in adult outpatients with suspected lower respiratory tract infection. We contacted authors of eligible studies for inclusion of data and for additional data as needed. The value of adding CRP measurement to a basic signs-and-symptoms prediction model was assessed. Outcome measures were improvement in discrimination between patients with and without pneumonia in primary care and improvement in risk classification, both within the individual studies and across studies. RESULTS: Authors of 8 eligible studies (n = 5308) provided their data sets. In all of the data sets, discrimination between patients with and without pneumonia improved after CRP measurement was added to the prediction model (extended model), with a mean improvement in the area under the curve of 0.075 (range 0.02-0.18). In a hypothetical cohort of 1000 patients, the proportion of patients without pneumonia correctly classified at low risk increased from 28% to 36% in the extended model, and the proportion with pneumonia correctly classified at high risk increased from 63% to 70%. The number of patients with pneumonia classified at low risk did not change (n = 4). Overall, the proportion of patients assigned to the intermediate-risk category decreased from 56% to 51%. INTERPRETATION: Adding CRP measurement to the diagnostic work-up for suspected pneumonia in primary care improved the discrimination and risk classification of patients. However, it still left a substantial group of patients classified at intermediate risk, in which clinical decision-making remains challenging.

Illness perception and related behaviour in lower respiratory tract infections­a European study.

BACKGROUND: Lower respiratory tract infection (LRTI) is a common presentation in primary care, but little is known about associated patients' illness perception and related behaviour. OBJECTIVE: To describe illness perceptions and related behaviour in patients with LRTI visiting their general practitioner (GP) and identify differences between European regions and types of health care system. METHODS: Adult patients presenting with acute cough were included. GPs recorded co morbidities and clinical findings. Patients filled out a diary for up to 4 weeks on their symptoms, illness perception and related behaviour. The chi-square test was used to compare proportions between groups and the Mann-Whitney U or Kruskal Wallis tests were used to compare means. RESULTS: Three thousand one hundred six patients from 12 European countries were included. Eighty-one per cent (n = 2530) of the patients completed the diary. Patients were feeling unwell for a mean of 9 (SD 8) days prior to consulting. More than half experienced impairment of normal or social activities for at least 1 week and were absent from work/school for a mean of 4 (SD 5) days. On average patients felt recovered 2 weeks after visiting their GP, but 21% (n = 539) of the patients did not feel recovered after 4 weeks. Twenty-seven per cent (n = 691) reported feeling anxious or depressed, and 28% (n = 702) re-consulted their GP at some point during the illness episode. Reported illness duration and days absent from work/school differed between countries and regions (North-West versus South-East), but there was little difference in reported illness course and related behaviour between health care systems (direct access versus gate-keeping). CONCLUSION: Illness course, perception and related behaviour in LRTI differ considerably between countries. These finding should be taken into account when developing International guidelines for LRTI and interventions for setting realistic expectations about illness course.

Validity of a clinical model to predict influenza in patients presenting with symptoms of lower respiratory tract infection in primary care.

BACKGROUND: Valid clinical predictors of influenza in patients presenting with lower respiratory tract infection (LRTI) symptoms would provide adequate patient information and reassurance. AIM: Assessing the validity of an existing diagnostic model (Flu Score) to detect influenza in LRTI patients. DESIGN AND SETTING: A European diagnostic study recruited 1801 adult primary care patients with LRTI-like symptoms existing ≤7 days between October and April 2007-2010. METHOD: History and physical examination findings were recorded and nasopharyngeal swabs taken. Polymerase chain reaction (PCR) for influenza A/B was performed as reference test. Diagnostic accuracy of the Flu Score (1× onset <48 hours + 2× myalgia + 1× chills or sweats + 2× fever and cough) was expressed as area under the curve (AUC), calibration slopes and likelihood ratios (LRs). RESULTS: A total of 273 patients (15%) had influenza on PCR. The AUC of the Flu Score during winter months was 0.66 [95% CI (95% confidence internal) 0.63-0.70]. During peak influenza season, both influenza prevalence (24%) and AUC were higher [0.71 (95% CI 0.66-0.76], but calibration remained poor. The Flu Score assigned 64% of the patients as 'low-risk' (10% had influenza, LR - 0.6). About 12% were classified as 'high risk' of whom 32% had influenza (LR + 2.7). During peak influenza season, 60% and 14% of patients were classified as low and high risk, respectively, with influenza prevalences being 14% (LR - 0.5) and 50% (LR + 3.2). CONCLUSION: The Flu-Score attributes a small subgroup of patients with a high influenza risk (prevalence 32%). However, clinical usefulness is limited because this group is small and the association between predicted and observed risks is poor. Considerable diagnostic imprecision remains when it comes to differentiating those with influenza on clinical grounds from the many other causes of LRTI in primary care. New point of care tests are required that accurately, rapidly and cost effectively detect influenza in patients with respiratory tract symptoms in primary care.

Diagnosing pneumonia in patients with acute cough: clinical judgment compared to chest radiography.

Pneumonia is often diagnosed and treated empirically. We set out to determine the diagnostic accuracy of clinical judgment based on signs and symptoms to detect radiographic pneumonia in patients presenting with acute cough in primary care. In 2810 European patients with acute cough, general practitioners (GPs) recorded whether they considered pneumonia to be present ("yes" or "no") immediately after history and physical examination. Chest radiography was performed within 1 week by local radiologists blind to other patient characteristics. 140 patients had radiographic pneumonia (5%), of whom 41 (29%) had been diagnosed as such. 31 (1%) patients had a clinical diagnosis that was not confirmed by radiography (n=2670). In clinically suspected pneumonia, 57% of subjects were subsequently diagnosed with radiographic pneumonia. Negative predictive value (NPV), sensitivity and specificity of GPs' clinical judgment were 96%, 29% and 99%, respectively. Compared to patients with a clinical diagnosis of pneumonia, less severe symptoms were found in radiographic pneumonia cases not suspected clinically (p<0.05). The predictive values of GPs' clinical judgment, particularly the high NPVs, are helpful in routine care. Nonetheless, the majority of diagnoses of radiographic pneumonias was not suspected on clinical grounds. There is a need to further support the detection of clinically relevant pneumonia in primary care.

Incidental chest radiographic findings in adult patients with acute cough.

PURPOSE: Imaging may produce unexpected or incidental findings with consequences for patients and ordering of future investigations. Chest radiography in patients with acute cough is among the most common reasons for imaging in primary care, but data on associated incidental findings are lacking. We set out to describe the type and prevalence of incidental chest radiography findings in primary care patients with acute cough. METHODS: We report on data from a cross-sectional study in 16 European primary care networks on 3,105 patients with acute cough, all of whom were undergoing chest radiography as part of a research study workup. Apart from assessment for specified signs of pneumonia and acute bronchitis, local radiologists were asked to evaluate any additional finding on the radiographs. For the 2,823 participants with good-quality chest radiographs, these findings were categorized according to clinical relevance based on previous research evidence and analyzed for type and prevalence by network, sex, age, and smoking status. RESULTS: Incidental findings were reported in 19% of all participants, and ranged from 0% to 25% by primary care network, with the network being an independent contributor (P <.001). Of all participants 3% had clinically relevant incidental findings. Suspected nodules and shadows were reported in 1.8%. Incidental findings were more common is older participants and smokers (P <. 001). CONCLUSIONS: Clinically relevant incidental findings on chest radiographs in primary care adult patients with acute cough are uncommon, and prevalence varies by setting.

External Validation of Prediction Models for Pneumonia in Primary Care Patients with Lower Respiratory Tract Infection: An Individual Patient Data Meta-Analysis.

BACKGROUND: Pneumonia remains difficult to diagnose in primary care. Prediction models based on signs and symptoms (S&S) serve to minimize the diagnostic uncertainty. External validation of these models is essential before implementation into routine practice. In this study all published S&S models for prediction of pneumonia in primary care were externally validated in the individual patient data (IPD) of previously performed diagnostic studies. METHODS AND FINDINGS: S&S models for diagnosing pneumonia in adults presenting to primary care with lower respiratory tract infection and IPD for validation were identified through a systematical search. Six prediction models and IPD of eight diagnostic studies (N total = 5308, prevalence pneumonia 12%) were included. Models were assessed on discrimination and calibration. Discrimination was measured using the pooled Area Under the Curve (AUC) and delta AUC, representing the performance of an individual model relative to the average dataset performance. Prediction models by van Vugt et al. and Heckerling et al. demonstrated the highest pooled AUC of 0.79 (95% CI 0.74-0.85) and 0.72 (0.68-0.76), respectively. Other models by Diehr et al., Singal et al., Melbye et al., and Hopstaken et al. demonstrated pooled AUCs of 0.65 (0.61-0.68), 0.64 (0.61-0.67), 0.56 (0.49-0.63) and 0.53 (0.5-0.56), respectively. A similar ranking was present based on the delta AUCs of the models. Calibration demonstrated close agreement of observed and predicted probabilities in the models by van Vugt et al. and Singal et al., other models lacked such correspondence. The absence of predictors in the IPD on dataset level hampered a systematical comparison of model performance and could be a limitation to the study. CONCLUSIONS: The model by van Vugt et al. demonstrated the highest discriminative accuracy coupled with reasonable to good calibration across the IPD of different study populations. This model is therefore the main candidate for primary care use.

Metagenomic analysis of a sample from a patient with respiratory tract infection reveals the presence of a γ-papillomavirus.

Previously unknown or unexpected pathogens may be responsible for that proportion of respiratory diseases in which a causative agent cannot be identified. The application of broad-spectrum, sequence independent virus discovery techniques may be useful to reduce this proportion and widen our knowledge about respiratory pathogens. Thanks to the availability of high-throughput sequencing (HTS) technology, it became today possible to detect viruses which are present at a very low load, but the clinical relevance of those viruses must be investigated. In this study we used VIDISCA-454, a restriction enzyme based virus discovery method that utilizes Roche 454 HTS system, on a nasal swab collected from a subject with respiratory complaints. A γ-papillomavirus was detected (complete genome: 7142 bp) and its role in disease was investigated. Respiratory samples collected both during the acute phase of the illness and 2 weeks after full recovery contained the virus. The patient presented antibodies directed against the virus but there was no difference between IgG levels in blood samples collected during the acute phase and 2 weeks after full recovery. We therefore concluded that the detected γ-papillomavirus is unlikely to be the causative agent of the respiratory complaints and its presence in the nose of the patient is not related to the disease. Although HTS based virus discovery techniques proved their great potential as a tool to clarify the etiology of some infectious diseases, the obtained information must be subjected to cautious interpretations. This study underlines the crucial importance of performing careful investigations on viruses identified when applying sensitive virus discovery techniques, since the mere identification of a virus and its presence in a clinical sample are not satisfactory proofs to establish a causative link with a disease.

Use of serum C reactive protein and procalcitonin concentrations in addition to symptoms and signs to predict pneumonia in patients presenting to primary care with acute cough: diagnostic study.

OBJECTIVES: To quantify the diagnostic accuracy of selected inflammatory markers in addition to symptoms and signs for predicting pneumonia and to derive a diagnostic tool. DESIGN: Diagnostic study performed between 2007 and 2010. Participants had their history taken, underwent physical examination and measurement of C reactive protein (CRP) and procalcitonin in venous blood on the day they first consulted, and underwent chest radiography within seven days. SETTING: Primary care centres in 12 European countries. PARTICIPANTS: Adults presenting with acute cough. MAIN OUTCOME MEASURES: Pneumonia as determined by radiologists, who were blind to all other information when they judged chest radiographs. RESULTS: Of 3106 eligible patients, 286 were excluded because of missing or inadequate chest radiographs, leaving 2820 patients (mean age 50, 40% men) of whom 140 (5%) had pneumonia. Re-assessment of a subset of 1675 chest radiographs showed agreement in 94% (κ 0.45, 95% confidence interval 0.36 to 0.54). Six published "symptoms and signs models" varied in their discrimination (area under receiver operating characteristics curve (ROC) ranged from 0.55 (95% confidence interval 0.50 to 0.61) to 0.71 (0.66 to 0.76)). The optimal combination of clinical prediction items derived from our patients included absence of runny nose and presence of breathlessness, crackles and diminished breath sounds on auscultation, tachycardia, and fever, with an ROC area of 0.70 (0.65 to 0.75). Addition of CRP at the optimal cut off of >30 mg/L increased the ROC area to 0.77 (0.73 to 0.81) and improved the diagnostic classification (net reclassification improvement 28%). In the 1556 patients classified according to symptoms, signs, and CRP >30 mg/L as "low risk" (<2.5%) for pneumonia, the prevalence of pneumonia was 2%. In the 132 patients classified as "high risk" (>20%), the prevalence of pneumonia was 31%. The positive likelihood ratio of low, intermediate, and high risk for pneumonia was 0.4, 1.2, and 8.6 respectively. Measurement of procalcitonin added no relevant additional diagnostic information. A simplified diagnostic score based on symptoms, signs, and CRP >30 mg/L resulted in proportions of pneumonia of 0.7%, 3.8%, and 18.2% in the low, intermediate, and high risk group respectively. CONCLUSIONS: A clinical rule based on symptoms and signs to predict pneumonia in patients presenting to primary care with acute cough performed best in patients with mild or severe clinical presentation. Addition of CRP concentration at the optimal cut off of >30 mg/L improved diagnostic information, but measurement of procalcitonin concentration did not add clinically relevant information in this group.