Community-acquired pneumonia in primary care: clinical assessment and the usability of chest radiography

Antibiotic Treatment for Lower Respiratory Tract Infections in Primary Care: A Register-Based Study Examining the Role of Radiographic Imaging

When imaging (i.e., chest-x-ray or computed tomography) is used to differentiate between acute bronchitis and pneumonia, many patients are being prescribed antibiotics despite the absence of radiographic pneumonia signs. This study of lower respiratory tract infections (LRTIs) with negative chest imaging compares cases where antibiotics were prescribed and not prescribed to find characteristics that could explain the prescription. Data were extracted from the regional electronic medical record system in Kronoberg County, Sweden, for patients aged 18-79 years diagnosed with acute bronchitis or pneumonia and who had any chest radiologic imaging between 2007-2014. Of 696 cases without evidence of pneumonia on imaging, 55% were prescribed antibiotics. Age, sex, and co-morbidity did not differ between those with or without antibiotics. The median level of C-reactive protein was low in both groups but differed significantly (21 vs. 10 mg/L; p < 0.001). Resident physicians prescribed antibiotics more frequently than interns or specialists (p < 0.001). It is unclear what features prompted the antibiotic prescribing in those with negative imaging indicating overuse of antibiotics for LRTIs.

Community-acquired pneumonia - use of chest x-rays for diagnosis in family practice

Background

According to guidelines, the diagnosis of pneumonia should be confirmed by chest x-ray, ensuring appropriate management and wise use of antibiotics. Our study aimed to describe use of x-rays by family doctors and patients following diagnosis of pneumonia in primary care practices in the north of Israel.

Methods

This was a retrospective database study including adults diagnosed with pneumonia, assessing rates of referral and actual use of chest x-rays. We examined rates of referral for chest x-rays and rates of adherence to the referral, according to age, gender, smoking status, comorbidities and distance of residence from the radiology facility.

Results

During one year there were 4,230 diagnosed cases of pneumonia in the practice, of which 2,503 were referred for chest x-rays, and 1,920 adhered to the referral (45% of those diagnosed with pneumonia). The rate of referral was higher when the radiology facility was located in the same city as the family doctor compared to outside the city (69.7% and 53.2%, p < 0.001). Patients aged 40–64 were referred more than patients aged 18–39 or 65+ (61.5% vs. 56.5% and 58.3%, p = 0.03). Actual use of chest x-rays (considering both referral and adherence) was more likely when the radiology facility was in the same health centre or city than when it was outside the city [OR = 2.4; 95% CI: 2.1–2.8]; patients aged 65 + or 40–64 were more likely to adhere to the referral for x-ray than those aged 18–39 [OR = 1.3; 95% CI: 1.1–1.6, OR = 1.2; 95% CI: 1.0–1.4, respectively].

Conclusion

Accessibility of radiology facilities seems to be an important factor associated with both doctors’ decisions and patients’ adherence to the referral for chest x-rays.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12875-022-01872-y.

Danish GPs' Experiences When Managing Patients Presenting to General Practice with Symptoms of Acute Lower Respiratory Tract Infections: A Qualitative Study

One of the most common indications for antibiotic prescribing in general practice is acute lower respiratory tract infections (LRTI). This study aimed to explore general practitioners' (GPs') considerations and experiences when managing patients with symptoms of an acute LRTI. Individual semi-structured interviews were conducted with seven GPs in the North Denmark Region from January to March 2020. Data were analysed by means of systematic text condensation. The analysis revealed four themes: (1) practicalities of assessing patients with LRTI, (2) assessment of the patient, (3) treatment decisions, and (4) patient expectations. The GPs described having developed individual diagnostic strategies and routines when managing patients with symptoms of an acute LRTI. However, a general assessment of the patient was essential to all the GPs and the diagnosis was seldom based on a single symptom or finding. Most GPs described having great faith in abnormal lung auscultation. The use of C-reactive protein testing served several purposes, such as deciding on the severity of the infection, prescribing antibiotics or not, and as a communicative tool. Diagnostic uncertainty is a driver of antibiotic use and clinical practice might benefit from the development of clinical prediction rules for diagnosing pneumonia.

Predictive Value of Clinician "Gestalt" in Pediatric Community-Acquired Pneumonia

OBJECTIVES

Validated prognostic tools for pediatric community-acquired pneumonia (CAP) do not exist. Thus, clinicians rely on "gestalt" in management decisions for children with CAP. We sought to determine the ability of clinician gestalt to predict severe outcomes.

METHODS

We performed a prospective cohort study of children 3 months to 18 years old presenting to a pediatric emergency department (ED) with lower respiratory infection and receiving a chest radiograph for suspected CAP from 2013 to 2017. Clinicians reported the probability that the patient would develop severe complications of CAP (defined as respiratory failure, empyema or effusion, lung abscess or necrosis, metastatic infection, sepsis or septic shock, or death). The primary outcome was development of severe complications.

RESULTS

Of 634 children, 37 (5.8%) developed severe complications. Of children developing severe complications after the ED visit, 62.1% were predicted as having <10% risk by the ED clinician. Sensitivity was >90% at the <1% predicted risk threshold, whereas specificity was >90% at the 10% risk threshold. Gestalt performance was poor in the low-intermediate predicted risk category (1%-10%). Clinicians had only fair ability to discriminate children developing complications from those who did not (area under the receiver operator characteristic curve 0.747), with worse performance from less experienced clinicians (area under the receiver operator characteristic curve 0.693).

CONCLUSIONS

Clinicians have only fair ability to discriminate children with CAP who develop severe complications from those who do not. Clinician gestalt performs best at very low or higher predicted risk thresholds, yet many children fall in the low-moderate predicted risk range in which clinician gestalt is limited. Evidence-based prognostic tools likely can improve on clinician gestalt, particularly when risk is low-moderate.

Community-acquired bacterial pneumonia in adults: An update

Community-acquired pneumonia (CAP) is the prominent cause of mortality and morbidity with important clinical impact across the globe. India accounts for 23 per cent of global pneumonia burden with case fatality rates between 14 and 30 per cent, and Streptococcus pneumoniae is considered a major bacterial aetiology. Emerging pathogens like Burkholderia pseudomallei is increasingly recognized as an important cause of CAP in Southeast Asian countries. Initial management in the primary care depends on clinical assessment while the hospitalized patients require combinations of clinical scores, chest radiography and various microbiological and biomarker assays. This comprehensive diagnostic approach together with additional sampling and molecular tests in selected high-risk patients should be practiced. Inappropriate therapy in CAP in hospitalized patients lengthens hospital stay and increases cost and mortality. In addition, emergence of multidrug-resistant organisms poses tough challenges in deciding empirical as well as definitive therapy. Developing local evidence on the cause and management should be a priority to improve health outcomes in CAP.

C-reactive protein influences the doctor's degree of suspicion of pneumonia in primary care: a prospective observational study

BACKGROUND

In primary care, the diagnosis of pneumonia is often based on history and clinical examination alone. However, a previous study showed that the general practitioner's degree of suspicion correlates well with findings on chest X-ray, when the C-reactive protein (CRP) value is known.

OBJECTIVES

The present study aimed to investigate to what extent the physician's degree of suspicion is affected by the CRP level when community-acquired pneumonia is suspected in primary care.

METHODS

A prospective observational study was conducted at five primary health care centres in Sweden between October 2015 and December 2017. Adult patients (n = 266) consulting their health care centre with symptoms of lower respiratory tract infection, where the physician suspected pneumonia, were included consecutively. Anamnestic information and findings from clinical examination were documented in a case report form. All patients were tested for CRP. The physicians rated their degree of suspicion as 'unsure,' 'quite sure,' and 'sure' before and after the CRP result.

RESULTS

The degree of suspicion of pneumonia changed in 69% of the cases; most often to a lower degree (40%). In 28% of the cases, there was no longer any suspicion of pneumonia after CRP.

CONCLUSION

Our results indicate that CRP testing highly influences the physician's degree of suspicion of pneumonia in primary care and that it seems to be of most value when not sure of the diagnosis.

Use of chest X-ray in the assessment of community acquired pneumonia in primary care - an intervention study

OBJECTIVES

The aim of this study was to explore if consequent use of chest X-ray (CXR), when the physician is not sure of the diagnosis of pneumonia after clinical examination and CRP-testing, favors a more restrictive prescribing of antibiotics.

DESIGN

This was an intervention study conducted between September 2015 and December 2017.

SETTING

Two intervention primary health care centers (PHCCs) and three control PHCCs in the southeast of Sweden.

INTERVENTION

All patients were referred for CXR when the physician´s suspicion of pneumonia was 'unsure', or 'quite sure' after CRP-testing. Control units managed patients according to their usual routine after clinical examination and CRP-testing.

SUBJECTS

A total of 104 patients were included in the intervention group and 81 patients in the control group. The inclusion criteria of the study were clinically suspected pneumonia in patients ≥18 years, with respiratory symptoms for more than 24 h. Main outcome measure: Antibiotic prescribing rate.

RESULTS

In the intervention group, 85% were referred for CXR and 69% were prescribed antibiotics, as compared to 26% and 77% in the control group. The difference in antibiotic prescribing rate was not statistically significant, unadjusted OR 0.68 [0.35-1.3] and adjusted OR 1.1 [CI 0.43-3.0]. A total of 24% of patients with negative CXR were prescribed antibiotics.

CONCLUSION

This study could not prove that use of CXR when the physician was not sure of the diagnosis of pneumonia results in lowered antibiotic prescribing rate in primary care. In cases of negative findings on CXR the physicians do not seem to rely on the outcome when it comes to antibiotic prescribing. Key Points Routine use of chest X-ray when the clinical diagnosis of pneumonia is uncertain has not been proven to result in lowered antibiotic prescribing rate. Physicians do not fully rely on chest X-ray outcome and to some extent prescribe antibiotics even if negative, when community-acquired pneumonia is suspected. Chest X-ray is already used in one out of four cases in routine primary care of pneumonia patients in Sweden.

Accuracy of Signs and Symptoms for the Diagnosis of Community-acquired Pneumonia: A Meta-analysis

BACKGROUND

Community-acquired pneumonia (CAP) is an important source of morbidity and mortality. However, overtreatment of acute cough illness with antibiotics is an important problem, so improved diagnosis of CAP could help reduce inappropriate antibiotic use.

METHODS

This was a meta-analysis of prospective cohort studies of patients with clinically suspected pneumonia or acute cough that used imaging as the reference standard. All studies were reviewed in parallel by two researchers and quality was assessed using the QUADAS-2 criteria. Summary measures of accuracy included sensitivity, specificity, likelihood ratios, the diagnostic odds ratio, and the area under the receiver operating characteristic curve (AUROCC) and were calculated using bivariate meta-analysis.

RESULTS

We identified 17 studies, of which 12 were judged to be at low risk of bias and the remainder at moderate risk of bias. The prevalence of CAP was 10% in nine primary care studies and was 20% in seven emergency department studies. The probability of CAP is increased most by an abnormal overall clinical impression suggesting CAP (positive likelihood ratio [LR+] = 6.32, 95% CI = 3.58 to 10.5), egophony (LR+ = 6.17, 95% CI = 1.34 to 18.0), dullness to percussion (LR+ = 2.62, 95% CI = 1.14 to 5.30), and measured temperature (LR+ = 2.52, 95% CI = 2.02 to 3.20), while it is decreased most by the absence of abnormal vital signs (LR- = 0.25, 95% CI = 0.11 to 0.48). The overall clinical impression also had the highest AUROCC at 0.741.

CONCLUSIONS

While most individual signs and symptoms were unhelpful, selected signs and symptoms are of value for diagnosing CAP. Teaching and performing these high value elements of the physical examination should be prioritized, with the goal of better targeting chest radiographs and ultimately antibiotics.

Accuracy of Biomarkers for the Diagnosis of Adult Community-acquired Pneumonia: A Meta-analysis

BACKGROUND

Biomarkers such as C-reactive protein (CRP) and procalcitonin may help distinguish community-acquired pneumonia (CAP) from other causes of lower respiratory tract infection.

METHODS

We performed a systematic review of the literature to identify prospective studies evaluating the accuracy of a biomarker in patients with acute cough or suspected CAP. We performed parallel abstraction of data regarding study inclusion, characteristics, quality, and test accuracy. Study quality was evaluated using QUADAS-2. Bivariate meta-analysis was performed using the mada package in R, and summary receiver operating characteristic (ROC) curves were created.

RESULTS

Fourteen studies met our inclusion and exclusion criteria; three were at low risk of bias and four at moderate risk of bias, largely due to failure to prespecify diagnostic thresholds. Considering all studies regardless of the cutoff used, CRP was most accurate (area under the ROC curve = 0.802), followed by leukocytosis (0.777) and procalcitonin (0.771). Lipopolysaccharide-binding protein and fibrinogen are promising, but were only studied in a single report. For CRP and procalcitonin, the positive and negative likelihood ratios (LR+ and LR-, respectively) varied inversely based on the cutoff. For CRP, LR+ and LR- were 2.08 and 0.32 for a cutoff of 20 mg/L, 3.64 and 0.36 for a cutoff of 50 mg/L, and 5.89 and 0.47 for a cutoff of 100 mg/L. For procalcitonin, LR+ and LR- were 2.50 and 0.39 for a cutoff of 0.10 µg/L, 5.43 and 0.62 for a cutoff of 0.25 µg/L, and 8.25 and 0.76 for a cutoff of 0.50 µg/L. The combination of CRP >49.5 mg/L and procalcitonin >0.1 µg/L had LR+ of 2.24 and LR- of 0.44.

CONCLUSIONS

The best evidence supports CRP as the preferred biomarker for diagnosis of outpatient CAP given its accuracy, low cost, and point-of-care availability.

Clinical gestalt to diagnose pneumonia, sinusitis, and pharyngitis: a meta-analysis

BACKGROUND

The overall clinical impression ('clinical gestalt') is widely used for diagnosis but its accuracy has not been systematically studied.

AIM

To determine the accuracy of clinical gestalt for the diagnosis of community-acquired pneumonia (CAP), acute rhinosinusitis (ARS), acute bacterial rhinosinusitis (ABRS), and streptococcal pharyngitis, and to contrast it with the accuracy of clinical decision rules (CDRs).

DESIGN AND SETTING

Systematic review and meta-analysis of outpatient diagnostic accuracy studies in ambulatory care.

METHOD

PubMed and Google were searched for studies in outpatients that reported sufficient data to calculate accuracy of the overall clinical impression and that used the same reference standard. Study quality was assessed using Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2), and measures of accuracy calculated using bivariate meta-analysis.

RESULTS

The authors identified 16 studies that met the inclusion criteria. The summary estimates for the positive (LR+) and negative likelihood ratios (LR-) were LR+ 7.7, 95% confidence interval (CI) = 4.8 to 11.5, and LR- 0.54, 95% CI = 0.42 to 0.65 for CAP in adults, LR+ 2.7, 95% CI = 1.1 to 4.3 and LR- 0.63, 95% CI = 0.20 to 0.98 for CAP in children, LR+ 3.0, 95% CI = 2.1 to 4.4 and LR- 0.37, 95% CI = 0.29 to 0.46 for ARS in adults, LR+ 3.9, 95% CI = 2.4 to 5.9 and LR- 0.33, 95% CI = 0.20 to 0.50 for ABRS in adults, and LR+ 2.1, 95% CI = 1.6 to 2.8 and LR- 0.47, 95% CI = 0.36 to 0.60 for streptococcal pharyngitis in adults and children. The diagnostic odds ratios were highest for CAP in adults (14.2, 95% CI = 9.0 to 21.0), ARS in adults (8.3, 95% CI = 4.9 to 13.1), and ABRS in adults (13.0, 95% CI = 5.0 to 27.0), as were the C-statistics (0.80, 0.77, and 0.84 respectively).

CONCLUSION

The accuracy of the overall clinical impression compares favourably with the accuracy of CDRs. Studies of diagnostic accuracy should routinely include the overall clinical impression in addition to individual signs and symptoms, and research is needed to optimise its teaching.

Clinical features for diagnosis of pneumonia among adults in primary care setting: A systematic and meta-review

Pneumonia results in significant morbidity and mortality worldwide. However, chest radiography may not be accessible in primary care setting. We aimed to evaluate clinical features and its diagnostic value to identify pneumonia among adults in primary care settings. Three academic databases were searched and included studies that assessed clinical predictors of pneumonia, adults without serious illness, have CXR and have conducted in primary care settings. We calculated sensitivity, specificity, positive and negative likelihood ratios, diagnostic odds ratio of each index test and the pool estimates for index tests. We identified 2,397 articles, of which 13 articles were included. In our meta-analysis, clinical features with the best pooled positive likelihood ratios were respiratory rate ≥20 min⁻¹ (3.47; 1.46–7.23), temperature ≥38 °C (3.21; 2.36–4.23), pulse rate >100 min⁻¹ (2.79; 1.71–4.33), and crackles (2.42; 1.19–4.69). Laboratory testing showed highest pooled positive likelihood ratios with PCT >0.25 ng/ml (7.61; 3.28–15.1) and CRP > 20 mg/l (3.76; 2.3–5.91). Cough, pyrexia, tachycardia, tachypnea, and crackles are limited as a single predictor for diagnosis of radiographic pneumonia among adults. Development of clinical decision rule that combine these clinical features together with molecular biomarkers may further increase overall accuracy for diagnosis of radiographic pneumonia among adults in primary care setting.

2018 recommendations for the management of community acquired pneumonia

Community-acquired pneumonia (CAP) is the leading cause of death worldwide. Despite the vast diversity of respiratory microbiota, Streptococcus pneumoniae remains the most prevalent pathogen among etiologic agents. Despite the significant decrease in the mortality rates for lower respiratory tract infections in recent decades, CAP ranks third as a cause of death in Brazil. Since the latest Guidelines on CAP from the Sociedade Brasileira de Pneumologia e Tisiologia (SBPT, Brazilian Thoracic Association) were published (2009), there have been major advances in the application of imaging tests, in etiologic investigation, in risk stratification at admission and prognostic score stratification, in the use of biomarkers, and in the recommendations for antibiotic therapy (and its duration) and prevention through vaccination. To review these topics, the SBPT Committee on Respiratory Infections summoned 13 members with recognized experience in CAP in Brazil who identified issues relevant to clinical practice that require updates given the publication of new epidemiological and scientific evidence. Twelve topics concerning diagnostic, prognostic, therapeutic, and preventive issues were developed. The topics were divided among the authors, who conducted a nonsystematic review of the literature, but giving priority to major publications in the specific areas, including original articles, review articles, and systematic reviews. All authors had the opportunity to review and comment on all questions, producing a single final document that was approved by consensus.

Efficacy of high doses of penicillin versus amoxicillin in the treatment of uncomplicated community acquired pneumonia in adults. A non-inferiority controlled clinical trial

Introduction

Community-acquired pneumonia (CAP) is treated with penicillin in some northern European countries.

Objectives

To evaluate whether high-dose penicillin V is as effective as high-dose amoxicillin for the treatment of non-severe CAP.

Design

Multicentre, parallel, double-blind, controlled, randomized clinical trial.

Setting

31 primary care centers in Spain.

Participants

Patients from 18 to 75 years of age with no significant associated comorbidity and with symptoms of lower respiratory tract infection and radiological confirmation of CAP were randomized to receive either penicillin V 1.6 million units, or amoxicillin 1000 mg three times per day for 10 days.

Main measurements

The main outcome was clinical cure at 14 days, and the primary hypothesis was that penicillin V would be non-inferior to amoxicillin with regard to this outcome, with a margin of 15% for the difference in proportions. EudraCT register 2012-003511-63.

Results

A total of 43 subjects (amoxicillin: 28; penicillin: 15) were randomized. Clinical cure was observed in 10 (90.9%) patients assigned to penicillin and in 25 (100%) patients assigned to amoxicillin with a difference of −9.1% (95% CI, −41.3% to 6.4%; p = .951) for non-inferiority. In the intention-to-treat analysis, amoxicillin was found to be 28.6% superior to penicillin (95% CI, 7.3–58.1%; p = .009 for superiority). The number of adverse events was similar in both groups.

Conclusions

There was a trend favoring high-dose amoxicillin versus high-dose penicillin in adults with uncomplicated CAP. The main limitation of this trial was the low statistical power due to the low number of patients included.

[Community-acquired pneumonia]

CLINICAL ISSUE

The diagnosis of community-acquired pneumonia (CAP) is often not possible based only on the clinical symptoms and biochemical parameters.

STANDARD RADIOLOGICAL METHODS

For every patient with the suspicion of CAP, a chest radiograph in two planes should be carried out. Additionally, a risk stratification for the decision between outpatient therapy or hospitalization is recommended.

METHODICAL INNOVATIONS

Based on the evaluation of the different radiological patterns as well as their extent and distribution, a rough allocation to so-called pathogen groups as well as a differentiation between viral and bacterial infections are possible; however, because different pathogens cause different patterns an accurate correlation is not feasible by relying purely on imaging.

ACHIEVEMENTS/PRACTICAL RECOMMENDATIONS

The radiological findings serve as proof or exclusion of pneumonia and can also be used to evaluate the extent of the disease (e.g. monolobular, multilobular, unilateral or bilateral). In cases of prolonged disease, suspicion of complications (e.g. pleural effusion or empyema, necrotizing pneumonia or abscess) or comorbid conditions (e.g. underlying pulmonary or mediastinal diseases) computed tomography is an important diagnostic tool in addition to chest radiography. Ultrasound is often used to diagnose pleural processes (e.g. parapneumonic effusion or pleural empyema).