Aetiology and prediction of pneumonia in lower respiratory tract infection in primary care

BACKGROUND: Knowledge of predominant pathogens and their association with outcome are of importance for the management of lower respiratory tract infection (LRTI). As antibiotic therapy is indicated in pneumonia and not in acute bronchitis, a predictor of pneumonia is needed. AIM: To describe the aetiology and outcome of LRTI in adults with pneumonic and adults with non-pneumonic LRTI treated in general practice and to identify predictors of radiographic pneumonia. DESIGN OF STUDY: Prospective, observational study. SETTING: Forty-two general practices and an outpatient clinic at the Department of Infectious Diseases, Odense University Hospital, Denmark. METHOD: A total of 364 adults diagnosed with community-acquired LRTI by their GP were studied with chest radiography, vital signs, biochemical markers of inflammation (C-reactive protein [CRP] and leukocyte count), and microbiological examinations. Primary outcome measure was hospitalisation within 4 weeks. RESULTS: Pneumonia was radiographically verified in 48 of 364 patients (13%). Bacterial infection was seen more often in patients with pneumonia (33% versus 17%, P<0.001), and viral infection more often in non-pneumonic patients (26% versus 13%, P<0.05). Hospitalisation was more common in patients with pneumonia compared to non-pneumonic patients (19 versus 3%, P<0.001); and in patients with pneumococcal infection compared with patients without pneumococcal infection (26 versus 4%, P = 0.001). The positive predictive value of GPs' diagnosis of pneumonia was low (0.23), but the vital signs, CRP, and leukocyte count had comparably low positive predictive values (0.23-0.30). CONCLUSION: Streptococcus pneumoniae was the most common bacterial pathogen. The risk of hospitalisation was highest among patients with pneumonia or pneumococcal infection; this emphasises the importance of coverage of S. pneumoniae when treatment is indicated. CRP should not be introduced for diagnosis of radiographic pneumonia in general practice before its use has been investigated in prospective, controlled intervention trials using CRP-guided treatment algorithms.     

Medication use in European primary care patients with lower respiratory tract infection: an observational study

Background

It is largely unknown what medication is used by patients with lower respiratory tract infection (LRTI).

Aim

To describe the use of self-medication and prescribed medication in adults presenting with LRTI in different European countries, and to relate self-medication to patient characteristics.

Design and setting

An observational study in 16 primary care networks in 12 European countries.

Method

A total of 2530 adult patients presenting with LRTI in 12 European countries filled in a diary on any medication used before and after a primary care consultation. Patient characteristics related to self-medication were determined by univariable and multivariable logistic regression analysis.

Results

The frequency and types of medication used differed greatly between European countries. Overall, 55.4% self-medicated before consultation, and 21.5% after consultation, most frequently with paracetamol, antitussives, and mucolytics. Females, non-smokers, and patients with more severe symptoms used more self-medication. Patients who were not prescribed medication during the consultation self-medicated more often afterwards. Self-medication with antibiotics was relatively rare.

Conclusion

A considerable amount of medication, often with no proven efficacy, was used by adults presenting with LRTI in primary care. There were large differences between European countries. These findings should help develop patient information resources, international guidelines, and international legislation concerning the availability of over-the-counter medication, and can also support interventions against unwarranted variations in care. In addition, further research on the effects of symptomatic medication is needed.     

Amoxicillin for acute lower respiratory tract infection in primary care: subgroup analysis by bacterial and viral aetiology

ObjectiveWe aimed to assess the effects of amoxicillin treatment in adult patients presenting to primary care with a lower respiratory tract infection (LRTI) who were infected with a potential bacterial, viral, or mixed bacterial/viral infection.MethodsThis multicentre randomized controlled trial focused on adults with LRTI not suspected for pneumonia. Patients were randomized to receive either antibiotic (amoxicillin 1 g) or placebo three times daily for 7 consecutive days using computer-generated random numbers (follow-up 28 days). In this secondary analysis of the trial, symptom duration (primary outcome), symptom severity (scored 0–6), and illness deterioration (reconsultation with new or worsening symptoms, or hospital admission) were analysed in pre-specified subgroups using regression models. Subgroups of interest were patients with a (strictly) bacterial, (strictly) viral, or combined infection, and patients with elevated values of procalcitonin, C-reactive protein, or blood urea nitrogen.Results2058 patients (amoxicillin n = 1036; placebo n = 1022) were randomized. Treatment did not affect symptom duration (n = 1793). Patients from whom a bacterial pathogen only was isolated (n = 207) benefited from amoxicillin in that symptom severity (n = 804) was reduced by 0.26 points (95% CI −0.48 to −0.03). The odds of illness deterioration (n = 2024) was 0.24 (95% CI 0.11 to 0.53) times lower from treatment with amoxicillin when both a bacterial and a viral pathogen were isolated (combined infection; n = 198).ConclusionsAmoxicillin may reduce the risk of illness deterioration in patients with a combined bacterial and viral infection. We found no clinically meaningful benefit from amoxicillin treatment in other subgroups.     

Procalcitonin versus C-reactive protein for predicting pneumonia in adults with lower respiratory tract infection in primary care

BACKGROUND: The role of procalcitonin in diagnosing bacterial infection has mainly been studied in patients with severe infections. There is no study on the value of procalcitonin measurements in adults with lower respiratory tract infection (LRTI) treated in primary care. AIM: To evaluate the accuracy of plasma procalcitonin in predicting radiographic pneumonia, bacterial infection, and adverse outcome in a population of adults with LRTI treated in primary care. DESIGN OF STUDY: Prospective, observational study. SETTING: Forty-two general practices and an outpatient clinic at the Department of Infectious Diseases, Odense University Hospital, Denmark. METHOD: A total of 364 patients with LRTI were prospectively enrolled from 42 general practices. Patients were examined with chest radiography, microbiological analyses, and measurements of C-reactive protein (CRP) and procalcitonin. The outcome measure was hospitalisation within 4 weeks of enrollment. RESULTS: Median procalcitonin was 0.05 ng/ml, which was below the functional sensitivity of the assay (0.06 ng/ml). In predicting radiographic pneumonia, bacterial infection, and hospitalisation, the sensitivities of procalcitonin >0.06 ng/ml were 0.70, 0.51, and 0.67, and of CRP were > or =20 mg/l, 0.73, 0.56, and 0.74 respectively. Corresponding positive predictive values were between 0.09 and 0.28. CONCLUSION: Both procalcitonin >0.06 ng/ml and CRP > or =20 mg/l were associated with radiographic pneumonia, bacterial infection, and subsequent hospitalisation, but positive predictive values were too low for any of the two inflammatory markers to be of use in clinical practice. To measure procalcitonin values accurately in the primary care setting, a more sensitive method is needed, but there was no indication that procalcitonin is superior to CRP in identifying patients with pneumonia, bacterial aetiology, or adverse outcome.     

Reducing uncertainty in managing respiratory tract infections in primary care

Respiratory tract infections (RTIs) remain the commonest reason for acute consultations in primary care in resource-rich countries. Their spectrum and severity has changed from the time that antibiotics were discovered, largely from improvements in the socioeconomic determinants of health as well as vaccination. The benefits from antibiotic treatment for common RTIs have been shown to be largely overstated. Nevertheless, serious infections do occur. Currently, no clinical features or diagnostic test, alone or in combination, adequately determine diagnosis, aetiology, prognosis, or response to treatment. This narrative review focuses on emerging evidence aimed at helping clinicians reduce and manage uncertainty in treating RTIs. Consultation rate and prescribing rate trends are described, evidence of increasing rates of complications are discussed, and studies and the association with antibiotic prescribing are examined. Methods of improving diagnosis and identifying those patients who are at increased risk of complications from RTIs, using clinical scoring systems, biomarkers, and point of care tests are also discussed. The evidence for alternative management options for RTIs are summarised and the methods for changing public and clinicians'' beliefs about antibiotics, including ways in which we can improve clinician–patient communication skills for management of RTIs, are described.     

Successful GP intervention with frequent attenders in primary care: randomised controlled trial.

BACKGROUND: Frequent attenders to GP clinics can place an unnecessary burden on primary care. Interventions to reduce frequent attendance have had mixed results. AIM: To assess the effectiveness of a GP intervention to reduce frequent-attender consultations. DESIGN OF STUDY: Randomised controlled trial with frequent attenders divided into an intervention group and two control groups (one control group was seen by GPs also providing care to patients undergoing the intervention). SETTING: A health centre in southern Spain. METHOD: Six GPs and 209 randomly-selected frequent attenders participated. Three GPs were randomly allocated to perform the new intervention: of the 137 frequent attenders registered with these three GPs, 66 were randomly allocated to receive the intervention (IG) and 71 to a usual care control group (CG2). The other three GPs offered usual care to the other 72 frequent attenders (CG1). The main outcome measure was the total number of consultations 1 year post-intervention. Baseline measurements were recorded of sociodemographic characteristics, provider-user interface, chronic illnesses, and psychosocial variables. GPs allocated to the new intervention received 15 hours' training which incorporated biopsychosocial, organisational, and relational approaches. After 1 year of follow-up frequent attenders were contacted. An intention-to-treat analysis was used. RESULTS: A multilevel model was built with three factors: time, patient, and doctor. After adjusting for covariates, the mean number of visits at 1 year in IG was 13.10 (95% confidence interval [CI]=11.39 to 14.94); in the CG1 group was 19.37 (95% CI=17.31 to 21.55); and in the CG2 group this was 16.72 (95% CI=4.84 to 18.72). CONCLUSION: The new intervention with GPs resulted in a significant and relevant reduction in frequent-attender consultations. Although further trials are needed, this intervention is recommended to GPs interested in reducing consultations by their frequent attenders.     

Limited value of chest radiography in predicting aetiology of lower respiratory tract infection in general practice.

BACKGROUND: In patients with lower respiratory tract infection (LRTI), changes on chest radiography are rare but poorly characterised, especially in general practice. AIM: To describe the range of findings on chest radiographs and the associations between these findings and the aetiology of LRTI. DESIGN OF STUDY: A prospective observational study. SETTING: General practices in the Leiden region, The Netherlands. METHOD: Adult patients with a defined LRTI were included. Standard medical history and physical examination were performed. Sputum, blood, and throat swabs were collected for diagnostic tests. Chest X-ray findings were assessed in relation to the aetiology. RESULTS: An abnormality on the chest X-ray was observed in 72 (55%) patients. Forty-five patients (35%) had changes due to infection, and 26 (20%) due to pneumonia. Pathogens were detected in 84 patients (33 single bacterial, 43 single viral, and 8 dual). Twelve (29%) patients with a bacterial infection (including dual infections) compared to four (9%) patients with viral infection had pneumonia on the chest X-ray (odds ratio [OR] = 4.0; 95% confidence interval [CI] = 1.2 to 13.8). Using the presence of pneumonia on chest X-ray as a test to predict a bacterial infection, the positive predictive value and the negative predictive value were 75% (CI = 48 to 93%) and 57% (CI = 45 to 69%), respectively. CONCLUSION: Pneumonia on the chest X-ray was found more frequently in patients with a bacterial infection than in patients with a viral infection. However, the sensitivity and the specificity are such that pneumonia on the chest X-ray is not a reliable test to discriminate between bacterial and non-bacterial LRTI in the general practice setting.     

Effectiveness of a smartphone application to promote physical activity in primary care: the SMART MOVE randomised controlled trial

Background

Physical inactivity is a major, potentially modifiable, risk factor for cardiovascular disease, cancer, and other chronic diseases. Effective, simple, and generalisable interventions that will increase physical activity in populations are needed.

Aim

To evaluate the effectiveness of a smartphone application (app) to increase physical activity in primary care.

Design and setting

An 8-week, open-label, randomised controlled trial in rural, primary care in the west of Ireland.

Method

Android smartphone users >16 years of age were recruited. All participants were provided with similar physical activity goals and information on the benefits of exercise. The intervention group was provided with a smartphone app and detailed instructions on how to use it to achieve these goals. The primary outcome was change in physical activity, as measured by a daily step count between baseline and follow-up.

Results

A total of 139 patients were referred by their primary care health professional or self-referred. In total, 37 (27%) were screened out and 12 (9%) declined to participate, leaving 90 (65%) patients who were randomised. Of these, 78 provided baseline data (intervention = 37; control = 41) and 77 provided outcome data (intervention = 37; control = 40). The mean daily step count at baseline for intervention and control groups was 4365 and 5138 steps per day respectively. After adjusting, there was evidence of a significant treatment effect (P = 0.009); the difference in mean improvement in daily step count from week 1 to week 8 inclusive was 1029 (95% confidence interval 214 to 1843) steps per day, favouring the intervention. Improvements in physical activity in the intervention group were sustained until the end of the trial.

Conclusion

A simple smartphone app significantly increased physical activity over 8 weeks in a primary care population.     

Clinical presentation and microbiological diagnosis in paediatric respiratory tract infection: a systematic review

Background

Antibiotic prescribing decisions for respiratory tract infection (RTI) in primary care could be improved if clinicians could target bacterial infections. However, there are currently no evidence-based diagnostic rules to identify microbial aetiology in children presenting with acute RTIs.

Aim

To analyse evidence of associations between clinical symptoms or signs and detection of microbes from the upper respiratory tract (URT) of children with acute cough.

Design and setting

Systematic review and meta-analysis.

Method

A literature search identified articles reporting relationships between individual symptoms and/or signs, and microbes detected from URT samples. Associations between pathogens and symptoms or signs were summarised, and meta-analysis conducted where possible.

Results

There were 9984 articles identified, of which 28 met inclusion criteria. Studies identified 30 symptoms and 41 signs for 23 microbes, yielding 1704 potential associations, of which only 226 (13%) have presently been investigated. Of these, relevant statistical analyses were presented for 175 associations, of which 25% were significant. Meta-analysis demonstrated significant relationships between respiratory syncytial virus (RSV) detection and chest retractions (pooled odds ratio [OR] 1.9, 95% confidence interval [CI] = 1.6 to 2.3), wheeze (pooled OR 1.7, 95% CI = 1.5 to 2.0), and crepitations/crackles (pooled OR 1.7, 95% CI = 1.3 to 2.2).

Conclusions

There was an absence of evidence for URT pathogens other than RSV. The meta-analysis identified clinical signs associated with RSV detection, suggesting clinical presentation may offer some, albeit poor, diagnostic value. Further research is urgently needed to establish the value of symptoms and signs in determining microbiological aetiology and improve targeting of antibiotics in primary care.     

Case finding for chronic obstructive pulmonary disease in primary care: a pilot randomised controlled trial

Background

Chronic obstructive pulmonary disease (COPD) is a major cause of morbidity and mortality. However, much of the disease burden remains undiagnosed.

Aim

To compare the yield and cost effectiveness of two COPD case-finding approaches in primary care.

Design and setting

Pilot randomised controlled trial in two general practices in the West Midlands, UK.

Method

A total of 1634 ever-smokers aged 35–79 years with no history of COPD or asthma were randomised into either a ‘targeted’ or ‘opportunistic’ case-finding arm. Respiratory questionnaires were posted to patients in the ‘targeted’ arm and provided to patients in the ‘opportunistic’ arm at routine GP appointments. Those reporting at least one chronic respiratory symptom were invited for spirometry. COPD was defined as pre-bronchodilator forced expiratory volume in 1 second/forced vital capacity (FEV1/FVC)<0.7 and FEV1<80% of predicted. Primary outcomes were the difference in the proportion of patients diagnosed with COPD and the cost per case detected.

Results

Twenty-six per cent (212/815) in the ‘targeted’ and 13.6% (111/819) in the ‘opportunistic’ arm responded to the questionnaire and 78.3% (166/212) and 73.0% (81/111), respectively, reported symptoms; 1.2% (10/815) and 0.7% (6/819) of patients in the ‘targeted’ and ‘opportunistic’ arms were diagnosed with COPD (difference in proportions = 0.5% [95% confidence interval {CI} = –0.5% to 3.08%]). Over a 12-month period, the ‘opportunistic’ case-finding yield could be improved to 1.95% (95% CI = 1.0% to 2.9%). The cost-per case detected was £424.56 in the ‘targeted’ and £242.20 in the ‘opportunistic’ arm.

Conclusion

Opportunistic case finding may be more effective and cost effective than targeting patients with a postal questionnaire alone. A larger randomised controlled trial with adequate sample size is required to test this.     

重症慢性阻塞性肺疾病急性加重期下呼吸道感染病原菌及其耐药性分析

目的:了解重症慢性阻塞性肺疾病急性加重期(AECOPD)患者下呼吸道感染病原菌的特点及耐药情况,指导临床合理用药。方法:取我院2007年10月~2010年9月住院的189例重症AECOPD患者合格痰标本及防污染毛刷刷取的气管内分泌物标本进行细菌培养、鉴定及药敏试验。结果:共分离病原菌147株,其中以革兰阴性杆菌占首位,达64.6%,依次为铜绿假单胞菌、不动杆菌、大肠埃希菌和阴沟肠杆菌。其次是革兰阳性球菌,占21.8%。真菌占13.6%,以白念珠菌检出率最高。药敏结果显示革兰阴性杆菌对第三代头孢菌素耐药严重,对哌拉西林-他唑巴坦、碳青霉烯类抗生素较敏感;革兰阳性球菌对青霉素、克林霉素、红霉素耐药率高,未发现对万古霉素耐药。结论:重症AECOPD患者下呼吸道感染病原菌以革兰阴性杆菌为主,且耐药现象明显,二重感染逐年增加,且占有较大比重。临床AECOPD患者选用抗生素治疗时应重视细菌培养及药敏试验,减少不合理用药,减少耐药菌株与二重感染产生。     

Antibiotics for lower respiratory tract infection in children presenting in primary care (ARTIC-PC): the predictive value of molecular testing

ObjectivesThis study aimed to assess whether the presence of bacteria or viruses in the upper airway of children presenting with uncomplicated lower respiratory tract infection (LRTI) predicts the benefit of antibiotics.MethodsChildren between 6 months and 12 years presenting to UK general practices with an acute LRTI were randomized to receive amoxicillin 50 mg/kg/d for 7 days or placebo. Children not randomized (ineligible or clinician/parental choice) could participate in a parallel observational study. The primary outcome was the duration of symptoms rated moderately bad or worse. Throat swabs were taken and analyzed for the presence of bacteria and viruses by multiplex PCR.ResultsSwab results were available for most participants in the trial (306 of 432; 71%) and in the observational (182 of 326; 59%) studies. Bacterial pathogens potentially sensitive to amoxicillin (Haemophilus influenzae, Moraxella catarrhalis, Streptococcus pneumoniae) were detected among 51% of the trial placebo group and 49% of the trial antibiotic group. The median difference in the duration of symptoms rated moderately bad or worse between antibiotic and placebo was similar when potentially antibiotic-susceptible bacteria were present (median: –1 day; 99% CI, –12.3 to 10.3) or not present (median: –1 day; 99% CI, –4.5 to 2.5). Furthermore, bacterial genome copy number did not predict benefit. There were similar findings for all secondary outcomes and when including the data from the observational study.DiscussionThere was no clear evidence that antibiotics improved clinical outcomes conditional on the presence or concentration of bacteria or viruses in the upper airway. Before deploying microbiologic point-of-care tests for children with uncomplicated LRTI in primary care, rigorous validating trials are needed.     

Association between point-of-care CRP testing and antibiotic prescribing in respiratory tract infections: a systematic review and meta-analysis of primary care studies

Background

Most patients with respiratory tract infections (RTIs) are prescribed antibiotics in general practice. However, there is little evidence that antibiotics bring any value to the treatment of most RTIs. Point-of-care C-reactive protein testing may reduce antibiotic prescribing.

Aim

To systematically review studies that have examined the association between point-of-care (POC) C-reactive protein testing and antibiotic prescribing for RTIs in general practice.

Design and setting

Systematic review and meta-analysis of randomised controlled trials and observational studies.

Method

MEDLINE^® and Embase were systematically searched to identify relevant publications. All studies that examined the association between POC C-reactive protein testing and antibiotic prescribing for patients with RTIs were included. Two authors independently screened the search results and extracted data from eligible studies. Dichotomous measures of outcomes were combined using risk ratios (RRs) with 95% confidence intervals (CIs) either by fixed or random-effect models.

Results

Thirteen studies containing 10 005 patients met the inclusion criteria. POC C-reactive protein testing was associated with a significant reduction in antibiotic prescribing at the index consultation (RR 0.75, 95% CI = 0.67 to 0.83), but was not associated with antibiotic prescribing at any time during the 28-day follow-up period (RR 0.85, 95% CI = 0.70 to 1.01) or with patient satisfaction (RR 1.07, 95% CI = 0.98 to 1.17).

Conclusion

POC C-reactive protein testing significantly reduced antibiotic prescribing at the index consultation for patients with RTIs. Further studies are needed to analyse the confounders that lead to the heterogeneity.     

Childhood urinary tract infection in primary care: a prospective observational study of prevalence,diagnosis, treatment,and recovery

BackgroundThe prevalence of targeted and serendipitous treatment for, and associated recovery from, urinary tract infection (UTI) in pre-school children is unknown.AimTo determine the frequency and suspicion of UTI in children who are acutely ill, along with details of antibiotic prescribing, its appropriateness, and whether that appropriateness impacted on symptom improvement and recovery.MethodSystematic urine sampling from children aged <5years presenting in primary care with acute illness with culture in NHS laboratories.ResultsOf 6079 children’s urine samples, 339 (5.6%) met laboratory criteria for UTI and 162 (47.9%) were prescribed antibiotics at the initial consultation. In total, 576/7101 (8.1%) children were suspected of having a UTI prior to urine sampling, including 107 of the 338 with a UTI (clinician sensitivity 31.7%). Children with a laboratory-diagnosed UTI were more likely to be prescribed antibiotics when UTI was clinically suspected than when it was not (86.0% versus 30.3%, P<0.001). Of 231 children with unsuspected UTI, 70 (30.3%) received serendipitous antibiotics (that is, antibiotics prescribed for a different reason). Overall, 176 (52.1%) children with confirmed UTI did not receive any initial antibiotic. Organism sensitivity to the prescribed antibiotic was higher when UTI was suspected than when treated serendipitously (77.1% versus 26.0%; P<0.001). Children with UTI prescribed appropriate antibiotics at the initial consultation improved a little sooner than those with a UTI who were not prescribed appropriate antibiotics initially (3.5 days versus 4.0 days; P = 0.005).ConclusionOver half of children with UTI on culture were not prescribed antibiotics at first presentation. Serendipitous UTI treatment was relatively common, but often inappropriate to the organism’s sensitivity. Methods for improved targeting of antibiotic treatment in children who are acutely unwell are urgently needed.     

Predicting the duration of symptoms in lower respiratory tract infection.

BACKGROUND: Acute lower respiratory tract infection (LRTI) presenting in primary care has a long natural history. Antibiotic treatment makes little or no difference to the duration of cough. Limited information is currently available regarding predictors of illness duration. AIM: To determine predictors of illness duration in acute LRTI in primary care. DESIGN OF STUDY: Secondary analysis of trial data to identify independent predictors of illness severity and duration. SETTING: Primary care. METHOD: Eight-hundred and seven patients aged 3 years and over with acute illness (21 days or less) presenting with cough as the main symptom plus at least one symptom or sign from sputum, chest pain, dyspnoea, or wheeze were recruited to the study. Main outcomes were duration of symptoms (rated at least a slight problem) and more severe symptoms (rated at least moderately bad). RESULTS: The average duration of cough (rated at least a slight problem) was 11.7 days and was shorter among children (duration -1.72 days; 95% confidence interval [CI] = -3.02 to -0.41) or in individuals with a history of fever (-1.22 days; 95% CI = -0.18 to 2.27). The duration of cough was longer among those with restricted activities on the day they saw the doctor (+0.69 days for each point of a 7-point scale). The duration of more severe symptoms was longer in those with a longer duration of symptoms prior to consultation, with a more severe cough on the day of seeing the doctor, and restriction of activities on the day of seeing the doctor. CONCLUSION: Illness duration may be predicted from a limited number of clinical symptoms and from prior history. These findings should be subjected to validation in a separate population. To minimise expectation about rapid resolution of illness, adults who have restricted activities could be advised that they are likely to experience symptoms for longer.