'I'm fishing really'--inflammatory marker testing in primary care: a qualitative study

Exploring Periodontal Conditions, Salivary Markers, and Systemic Inflammation in Patients with Cardiovascular Diseases

(1) Background: This cross-sectional investigation appreciated the role of serum C-reactive protein (CRP), several hematologic-cell markers, and salivary inflammation-related molecules [calprotectin (S100A8/A9), interleukin-1β (IL-1β), kallikrein] to predict periodontitis in patients with atherosclerotic cardiovascular disease (ACVD), arrhythmia, or both. Also, we appreciated the relationship between the inflammatory burden and periodontal destruction with the type of cardiac pathology. (2) Methods: Demographic, behavioral characteristics, periodontal indicators, blood parameters, and saliva samples were collected. (3) Results: All 148 patients exhibited stage II or III/IV periodontitis. Stage III/IV cases exhibited significantly increased S100A8/A9 levels (p = 0.004). A positive correlation between S100A8/A9 and IL-1β [0.35 (<0.001)], kallikrein [0.55 (<0.001)], and CRP [0.28 (<0.001)] was observed. Patients with complex cardiac involvement had a significantly higher number of sites with attachment loss ≥ 5 mm [19 (3-30)] compared to individuals with only arrhythmia [9 (3.25-18)] or ACVD [5 (1-12)] [0.048♦ {0.162/0.496/0.14}]. (4) Conclusions: Severe, extensive attachment loss may be indicative of patients with complex cardiac conditions, which underscores the essential role of periodontal status in relation to systemic diseases. The correlations between the rising trends of the inflammatory parameters suggest a potential interconnection between oral and systemic inflammation.

GPs' perspectives on diagnostic tests for children: a qualitative interview study

BACKGROUND

Most healthcare contacts for children in the UK occur in general practice. Diagnostic tests can be beneficial in narrowing differential diagnoses; however, there is substantial variation in the use of tests for children in general practice. Unwarranted variation in testing can lead to variation in quality of care and may exacerbate health inequities. To our knowledge, no previous study has tried to understand why variation in testing exists for children in general practice.

AIM

To explore GPs' perspectives on using diagnostic tests for children in primary care and the underlying drivers of variation.

DESIGN AND SETTING

Qualitative study in which semi-structured interviews were conducted with GPs and trainee GPs in England.

METHOD

Interviews were conducted with 18 GPs and two trainee GPs between April and June 2023. The interviews were transcribed and analysed using reflexive thematic analysis.

RESULTS

GPs reflected that their approach to testing in children differed from their approach to testing in adults: their threshold to test was higher, and their threshold to refer to specialists was lower. GPs' perceptions of test utility varied, including objective testing for asthma. Perceived drivers of variation in testing were intrinsic (clinician-specific) factors relating to their risk tolerance and experience; and extrinsic factors, including disease prevalence, parental concern and expectations of health care, workforce changes leading to fragmentation in care, time constraints, and differences in guidelines.

CONCLUSION

The findings of this study identify actionable issues for clinicians, researchers, and policymakers to address gaps in education, evidence, and guidance, reduce unwarranted differences in test use, and improve the quality of health care delivered to children in general practice.

Systemic Impact of Subgingival Infection Control in Periodontitis Patients with Cardiovascular Disease: A Narrative Review

INTRODUCTION

Periodontitis, an infectious inflammatory condition, is a key contributor to sustained systemic inflammation, intricately linked to atherosclerotic cardiovascular disease (CVD), the leading cause of death in developed nations. Treating periodontitis with subgingival mechanical instrumentation with or without adjunctive antimicrobials reduces the microbial burden and local inflammation, while also potentially bringing systemic benefits for patients with both periodontitis and CVD. This review examines systemic effects of subgingival instrumentation with or without antimicrobial products in individuals with periodontitis and CVD, and explores intricate pathogenetic interactions between periodontitis and CVD.

MATERIAL AND METHODS

English-language databases (PubMed MEDLINE and Cochrane Library) were searched for studies assessing the effects of nonsurgical periodontal therapies in periodontitis patients with or without CVD.

RESULTS

While the ability of periodontal therapy to reduce mortality- and morbidity-related outcomes in CVD patients with periodontitis remains uncertain, some studies indicate a decrease in inflammatory markers and blood cell counts. Subgingival mechanical instrumentation delivered over multiple short sessions carries lower risks of adverse effects, particularly systemic inflammation, compared to the full-mouth delivery, making it a preferable option for CVD patients.

CONCLUSIONS

Subgingival mechanical instrumentation, ideally conducted in a quadrant-based therapeutic approach, to decontaminate periodontal pockets has the potential to reduce both local and systemic inflammation with minimal adverse effects in patients suffering from periodontitis and concurrent CVD.

Assessment of prognostic biomarkers in sudden sensorineural hearing loss: A systematic review and meta-analysis

Sudden sensorineural hearing loss (SSNHL) is defined as hearing loss of more than 30 dB in less than 72 h. SSNHL is a frequent complaint and an emergency in otolaryngology. Various biomarkers have been used to determine the prognosis of SSNHL. This systematic review and meta-analysis aims to evaluate the relationship between the different biomarkers and the prognosis of SSNHL. We searched English-language literature up to October 2022 in four databases, including PubMed, Google Scholar, Cochrane, and Science Direct. This search was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. This study was reported in the International Prospective Register of Systematic Reviews (PROSPERO) database (ID = CRD42022369538). All studies examining the role of neutrophil to lymphocyte ratio (NLR) concluded that higher NLR is associated with a worse prognosis. The results of studies regarding the relationship between platelet to lymphocyte ratio (PLR) and tumor necrosis factor (TNF) are controversial. Other factors shown to be associated with SSNHL include Glycated hemoglobin (HbA1C), blood glucose, iron levels, serum endocan, salusin-beta, and bone turnover biomarkers. This meta-analysis showed that PLR, NLR, and neutrophils were significantly different between recovered and non-recovered patients. PLR, NLR, and neutrophil count are reliable tools to assess the prognosis of patients with SSNHL.

The erythrocyte sedimentation rate (ESR) in canine inflammation

The clinical application of the erythrocyte sedimentation rate (ESR) assay is challenging due to its long processing time. However, in 2020 a new automated instrument for veterinary ESR was released and validated. This study sought: (1) to refine the proposed reference range (reference interval, RI) for canine ESR; (2) to compare the ESR values of healthy and sick dogs; and (3) to correlate ESR with other inflammatory markers such as C-reactive protein (CRP), fibrinogen, albumin:globulin ratio (A/G), and neutrophil-to-lymphocyte ratio (NLR); and also (4) to study ESR behavior across illnesses of varying durations. A prospective cohort study of 396 client-owned dogs (n = 120 healthy and n = 276 sick dogs) was conducted. Animals with a full clinical evaluation, complete hematobiochemical profile and a final diagnosis were included. ESR was performed according to manufacturer's instructions using the same 1 mL K3-EDTA tube used for the complete blood count. The RI was established at 1-8 mm/h in 14 min. Sick dogs had a significantly faster ESR (median 10 mm/h) than healthy dogs (median 1 mm/h; P < 0.0001). ESR was positively correlated with NLR (r = 0.36), CRP (r = 0.18) and fibrinogen (r = 0.56) and negatively correlated with A/G (r = -0.37). Dogs with an acute-on-chronic disease had the highest ESR values (median 17 mm/h) compared with either acute (median 11 mm/h; P < 0.001) or chronic diseases (median 7 mm/h; P = 0.001). ESR was confirmed as a reliable canine inflammatory marker, positively correlating with the main inflammatory markers in dogs and significantly different between sick and healthy dogs. The ESR assay appears useful especially in dogs with an acute clinical presentation, with or without an underlying chronic condition.

Blood tests in primary care: A qualitative study of communication and decision-making between doctors and patients

Objective

Blood tests are commonly used in primary care as a tool to aid diagnosis, and to offer reassurance and validation for patients. If doctors and patients do not have a shared understanding of the reasons for testing and the meaning of results, these aims may not be fulfilled. Shared decision‐making is widely advocated; yet, most research focusses on treatment decisions rather than diagnostic decisions. The aim of this study was to explore communication and decision‐making around diagnostic blood tests in primary care.

Methods

Qualitative interviews were undertaken with patients and clinicians in UK primary care. Patients were interviewed at the time of blood testing, with a follow‐up interview after they received test results. Interviews with clinicians who requested the tests provided paired data to compare clinicians' and patients' expectations, experiences and understandings of tests. Interviews were analysed thematically using inductive and deductive coding.

Results

A total of 80 interviews with 28 patients and 19 doctors were completed. We identified a mismatch in expectations and understanding of tests, which led to downstream consequences including frustration, anxiety and uncertainty for patients. There was no evidence of shared decision‐making in consultations preceding the decision to test. Doctors adopted a paternalistic approach, believing that they were protecting patients from anxiety.

Conclusion

Patients were not able to develop informed preferences and did not perceive that choice is possible in decisions about testing, because they did not have sufficient information and a shared understanding of tests. A lack of shared understanding at the point of decision‐making led to downstream consequences when test results did not fulfil patients' expectations. Although shared decision‐making is recommended as best practice, it does not reflect the reality of doctors' and patients' accounts of testing; a broader model of shared understanding seems to be more relevant to the complexity of primary care diagnosis.

Patient or Public Contribution

A patient and public involvement group comprising five participants with lived experience of blood testing in primary care met regularly during the study. They contributed to the development of the research objectives, planning recruitment methods, reviewing patient information leaflets and topic guides and also contributed to discussion of emerging themes at an early stage in the analysis process.

Combining simple blood tests to identify primary care patients with unexpected weight loss for cancer investigation: Clinical risk score development, internal validation, and net benefit analysis

BACKGROUND

Unexpected weight loss (UWL) is a presenting feature of cancer in primary care. Existing research proposes simple combinations of clinical features (risk factors, symptoms, signs, and blood test data) that, when present, warrant cancer investigation. More complex combinations may modify cancer risk to sufficiently rule-out the need for investigation. We aimed to identify which clinical features can be used together to stratify patients with UWL based on their risk of cancer.

METHODS AND FINDINGS

We used data from 63,973 adults (age: mean 59 years, standard deviation 21 years; 42% male) to predict cancer in patients with UWL recorded in a large representative United Kingdom primary care electronic health record between January 1, 2000 and December 31, 2012. We derived 3 clinical prediction models using logistic regression and backwards stepwise covariate selection: Sm, symptoms-only model; STm, symptoms and tests model; Tm, tests-only model. Fifty imputations replaced missing data. Estimates of discrimination and calibration were derived using 10-fold internal cross-validation. Simple clinical risk scores are presented for models with the greatest clinical utility in decision curve analysis. The STm and Tm showed improved discrimination (area under the curve ≥ 0.91), calibration, and greater clinical utility than the Sm. The Tm was simplest including age-group, sex, albumin, alkaline phosphatase, liver enzymes, C-reactive protein, haemoglobin, platelets, and total white cell count. A Tm score of 5 balanced ruling-in (sensitivity 84.0%, positive likelihood ratio 5.36) and ruling-out (specificity 84.3%, negative likelihood ratio 0.19) further cancer investigation. A Tm score of 1 prioritised ruling-out (sensitivity 97.5%). At this threshold, 35 people presenting with UWL in primary care would be referred for investigation for each person with cancer referred, and 1,730 people would be spared referral for each person with cancer not referred. Study limitations include using a retrospective routinely collected dataset, a reliance on coding to identify UWL, and missing data for some predictors.

CONCLUSIONS

Our findings suggest that combinations of simple blood test abnormalities could be used to identify patients with UWL who warrant referral for investigation, while people with combinations of normal results could be exempted from referral.

Association of bacterial vaginosis with periodontitis in a cross-sectional American nationwide survey

To explore the association between bacterial vaginosis (BV) and periodontitis (PD) and to determine whether PD and BV might be linked with systemic serum alterations. We used the National Health and Nutrition Examination Survey 2001-2004, with women aged 18-49 years old and diagnosed with or without BV according to Nugent's method. PD was defined according to the 2012 case definition. We compared serum counts according to the presence of PD and the presence of BV. Multivariable regression was used to explore and identify relevant variables towards the presence of BV. 961 women fulfilled the inclusion criteria. In women with BV, PD was associated with higher inflammation, characterized by increased white blood cells (p = 0.006) and lymphocyte (p = 0.009) counts. Predictive models presented a statistically significant association between PD and BV [Odds Ratio (OD) = 1.69, 95% Confidence Interval (CI): 1.09-2.61 for periodontitis; OD = 2.37, 95% CI: 1.30-4.29 for severe PD]. Fully adjusted models for age, smoking, body mass index, diabetes mellitus and number of systemic conditions reinforced this association [OD = 1.71, 95% CI: 1.06-2.76 for PD; OD = 2.21, 95% CI: 1.15-4.25 for severe PD]. An association between BV and PD is conceivable. PD was associated with higher systemic markers of inflammation in women with BV. Our data is novel and could serve as a foundation to guide future studies in the confirmation of this association and the underlying mechanisms.

Periodontitis and circulating blood cell profiles: a systematic review and meta-analysis

Periodontitis is a chronic inflammatory disease with local and systemic implications. Evidence suggests consistent hematologic changes associated with periodontitis. Our aim was to critically appraise the available evidence on hemogram, leukogram, and thrombogram alterations in otherwise healthy patients suffering from periodontitis when compared with controls. For this systematic review (SR), we searched MEDLINE, Web of Science, EMBASE, and the Cochrane Library (CENTRAL) for studies published up to June 2020. Both observational and interventional studies with baseline standard hematologic levels were included. Outcomes of interest were baseline hemogram, leukogram, and thrombogram values and the impact of periodontitis treatment on these outcomes. Upon risk of bias assessment, data extraction and both qualitative and quantitative (standardized mean differences) analyses were performed. Random-effects meta-analyses were performed to provide pooled estimates. The Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines were followed (PROSPERO Reg. No. CRD42020164531). A total of 45 studies, eight intervention and 37 case-control studies, were identified after the final search of 3,012 titles. Following quality assessment, 43 articles were deemed to have low risk of bias, and two articles moderate risk. Meta-analyses confirmed that periodontitis was associated with both white and red cell lineages. Severe chronic periodontitis was associated with greater white blood cell counts (mean difference [MD] = 0.53, 95% confidence interval [CI]: 0.26-0.79) when compared with controls. Periodontitis was associated with a larger number of neutrophils (MD = 7.16%, 95% CI: 5.96-8.37) and lower mean platelet volume (MD = 0.30 fL, 95% CI: 0.49 to -0.10) compared with healthy participants. Nonsurgical periodontal treatment was associated with a decrease in white blood cell (WBC) levels (MD = 0.28 10⁹/L, 95% CI: -0.47 to -0.08) in patients with chronic periodontitis. Periodontitis is associated with hematologic changes (Strength of Recommendation Taxonomy [SORT] A recommendation). Higher WBC levels, higher neutrophil levels, higher erythrocyte sedimentation rate, and lower mean platelet volumes are the most common blood count findings. The association between periodontitis and WBC could be causal in nature. Further assessment to determine whether periodontitis causes changes in circulating blood cells and to identify the molecular mechanisms underlying these associations is warranted.

Rwandan primary healthcare providers' perception of their capability in the diagnostic practice

BACKGROUND

Skill-mix imbalance is a global concern for primary healthcare in low-income countries. In Rwanda, primary healthcare facilities (health centres, HCs) are predominantly led by nurses. They have to diagnose a multitude of health complaints. Whether they feel capable of undertaking this responsibility has yet to be explored.

AIM

This study explored how healthcare providers (HPs) at Rwandan HCs perceived their capability in the diagnostic practice.

SETTING

Rural and urban HCs in Muhanga district, Rwanda.

METHOD

Qualitative, semi-structured interviews with nurses and clinical officers, and observations of consultations were made. Findings were analysed thematically.

RESULTS

Rwandan HPs were confident in their competences to perform diagnostic procedures although nurses felt that the responsibilities lay beyond their professional training. Clinical officers believed that their professional training prepared them to function competently and autonomously in the diagnostic practice, although all HPs experienced a high dependency on medical history taking, physical examination and laboratory tests for reaching a diagnosis. Resource constraints (time, rooms and laboratory tests) were seen as a barrier to perform diagnostic tasks optimally, and HPs experienced in-service training and supervision as insufficient. They increased their diagnostic competences through work experience, self-learning and supportive peer collaboration.

CONCLUSION

Clinical officers perceived themselves as capable in the diagnostic practice. Nurses may compensate for insufficient school training through in-service learning opportunities and feel capable in the diagnostic practice. Formative mentorship schemes and tailored education may prove valuable, but further research on how to improve HPs' diagnostic capability in Rwanda's primary healthcare sector is needed.

Prioritising primary care patients with unexpected weight loss for cancer investigation: diagnostic accuracy study

OBJECTIVE

To quantify the predictive value of unexpected weight loss (WL) for cancer according to patient's age, sex, smoking status, and concurrent clinical features (symptoms, signs, and abnormal blood test results).

DESIGN

Diagnostic accuracy study.

SETTING

Clinical Practice Research Datalink electronic health records data linked to the National Cancer Registration and Analysis Service in primary care, England.

PARTICIPANTS

63 973 adults (≥18 years) with a code for unexpected WL from 1 January 2000 to 31 December 2012.

MAIN OUTCOME MEASURES

Cancer diagnosis in the six months after the earliest weight loss code (index date). Codes for additional clinical features were identified in the three months before to one month after the index date. Diagnostic accuracy measures included positive and negative likelihood ratios, positive predictive values, and diagnostic odds ratios.

RESULTS

Of 63 973 adults with unexpected WL, 37 215 (58.2%) were women, 33 167 (51.8%) were aged 60 years or older, and 16 793 (26.3%) were ever smokers. 908 (1.4%) had a diagnosis of cancer within six months of the index date, of whom 882 (97.1%) were aged 50 years or older. The positive predictive value for cancer was above the 3% threshold recommended by the National Institute for Health and Care Excellence for urgent investigation in male ever smokers aged 50 years or older, but not in women at any age. 10 additional clinical features were associated with cancer in men with unexpected WL, and 11 in women. Positive likelihood ratios in men ranged from 1.86 (95% confidence interval 1.32 to 2.62) for non-cardiac chest pain to 6.10 (3.44 to 10.79) for abdominal mass, and in women from 1.62 (1.15 to 2.29) for back pain to 20.9 (10.7 to 40.9) for jaundice. Abnormal blood test results associated with cancer included low albumin levels (4.67, 4.14 to 5.27) and raised values for platelets (4.57, 3.88 to 5.38), calcium (4.28, 3.05 to 6.02), total white cell count (3.76, 3.30 to 4.28), and C reactive protein (3.59, 3.31 to 3.89). However, no normal blood test result in isolation ruled out cancer. Clinical features co-occurring with unexpected WL were associated with multiple cancer sites.

CONCLUSION

The risk of cancer in adults with unexpected WL presenting to primary care is 2% or less and does not merit investigation under current UK guidelines. However, in male ever smokers aged 50 years or older and in patients with concurrent clinical features, the risk of cancer warrants referral for invasive investigation. Clinical features typically associated with specific cancer sites are markers of several cancer types when they occur with unexpected WL.

Monocyte-to-high-density lipoprotein cholesterol ratio is associated with the presence and size of thyroid nodule irrespective of the gender

Background

Systemic inflammation may be involved in the formation and progression of thyroid nodule (TN). The aim of this large-scale study was to investigate the association of several simple inflammatory markers with the presence and size of TN.

Methods

A total of 133,698 adults were included for the current analysis. The neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), lymphocyte-to-monocyte ratio (LMR), and monocyte-to-high-density lipoprotein cholesterol ratio (MHR) were calculated. The logistic regression was used to explore the association of the four markers with the presence and size of TN.

Results

The prevalence of TN was 55.1% among females and 44% among males; 13% of women and 8% of men had non-micronodule. In women, MHR and PLR were significantly associated with the presence of TN and non-micronodule; in men, MHR and NLR were significantly associated with the presence of TN and non-micronodule.

Conclusions

As a low-cost, simple, and reproducible inflammatory marker, MHR is strongly associated with the presence and size of TN irrespective of the gender.

Educational intervention to optimise serum immunoglobulin test use in Irish primary care: an interrupted time series with segmented regression analysis

BACKGROUND

Implementation science experts recommend that theory-based strategies, developed in collaboration with healthcare professionals, have greater chance of success.

AIM

This study evaluated the impact of a theory-based strategy for optimising the use of serum immunoglobulin testing in primary care.

DESIGN AND SETTING

An interrupted time series with segmented regression analysis in the Cork-Kerry region, Ireland. An intervention was devised comprising a guideline and educational messages-based strategy targeting previously identified GP concerns relevant to testing for serum immunoglobulins.

METHOD

Interrupted time series with segmented regression analysis was conducted to evaluate the intervention, using routine laboratory data from January 2012 to October 2016. Data were organised into fortnightly segments (96 time points pre-intervention and 26 post-intervention) and analysed using incidence rate ratios with their corresponding 95% confidence intervals.

RESULTS

In the most parsimonious model, the change in trend before and after the introduction of the intervention was statistically significant. In the 1-year period following the implementation of the strategy, test orders were falling at a rate of 0.42% per fortnight (P<0.001), with an absolute reduction of 0.59% per fortnight, corresponding to a reduction of 14.5% over the 12-month study period.

CONCLUSION

The authors' tailored guideline combined with educational messages reduced serum immunoglobulin test ordering in primary care over a 1-year period. Given the rarity of the conditions for which the test is utilised and the fact that the researchers had only population-level data, further investigation is required to examine the clinical implications of this change in test-ordering patterns.

Erythrocyte Sedimentation Rate and C-Reactive Protein in Acute Inflammation

OBJECTIVES

To assess the diagnostic accuracy of erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) in acute inflammation.

METHODS

PubMed and Scopus were searched and eligible articles were screened for methodologic quality using the Quality Assessment of the Diagnostic Accuracy Studies-Revised. Meta-analysis with calculation of pooled sensitivity (Se), specificity (Sp), and summary area under the curve (SAUC) was performed.

RESULTS

Twenty-nine studies were eligible. Se and Sp were 0.78 and 0.68 (SAUC = 0.80) for ESR in orthopedic infections and 0.79 and 0.70 (SAUC = 0.81) for CRP. For the diagnosis of other various inflammatory conditions, CRP had a superior diagnostic accuracy, with a Se of 0.86, Sp of 0.67, and SAUC of 0.86 compared with a Se of 0.77, Sp of 0.59, and SAUC of 0.75 for ESR. Heterogeneity among studies was elevated. Combined use of ESR and CRP yielded higher diagnostic accuracy.

CONCLUSIONS

Despite observed heterogeneity among studies, ESR and CRP have a similar diagnostic accuracy in assessment of inflammation, especially in orthopedic conditions.

Added value and cascade effects of inflammatory marker tests in UK primary care: a cohort study from the Clinical Practice Research Datalink

BACKGROUND

Inflammatory markers (C-reactive protein, erythrocyte sedimentation rate, and plasma viscosity) are commonly used in primary care. Though established for specific diagnostic purposes, there is uncertainty around their utility as a non-specific marker to rule out underlying disease in primary care.

AIM

To identify the value of inflammatory marker testing in primary care as a rule-out test, and measure the cascade effects of testing in terms of further blood tests, GP appointments, and referrals.

DESIGN AND SETTING

Cohort study of 160 000 patients with inflammatory marker testing in 2014, and 40 000 untested age, sex, and practice-matched controls, using UK primary care data from the Clinical Practice Research Datalink.

METHOD

The primary outcome was incidence of relevant disease, including infections, autoimmune conditions, and cancers, among those with raised versus normal inflammatory markers and untested controls. Process outcomes included rates of GP consultations, blood tests, and referrals in the 6 months after testing.

RESULTS

The overall incidence of disease following a raised inflammatory marker was 15%: 6.3% infections, 5.6% autoimmune conditions, 3.7% cancers. Inflammatory markers had an overall sensitivity of <50% for the primary outcome, any relevant disease (defined as any infections, autoimmune conditions, or cancers). For 1000 inflammatory marker tests performed, the authors would anticipate 236 false-positives, resulting in an additional 710 GP appointments, 229 phlebotomy appointments, and 24 referrals in the following 6 months.

CONCLUSION

Inflammatory markers have poor sensitivity and should not be used as a rule-out test. False-positive results are common and lead to increased rates of follow-on GP consultations, tests, and referrals.

Use of multiple inflammatory marker tests in primary care: using Clinical Practice Research Datalink to evaluate accuracy

Background

Research comparing C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), and plasma viscosity (PV) in primary care is lacking. Clinicians often test multiple inflammatory markers, leading to concerns about overuse.

Aim

To compare the diagnostic accuracies of CRP, ESR, and PV, and to evaluate whether measuring two inflammatory markers increases accuracy.

Design and setting

Prospective cohort study in UK primary care using the Clinical Practice Research Datalink.

Method

The authors compared diagnostic test performance of inflammatory markers, singly and paired, for relevant disease, defined as any infections, autoimmune conditions, or cancers. For each of the three tests (CRP, ESR, and PV), sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and area under receiver operator curve (AUC) were calculated.

Results

Participants comprised 136 961 patients with inflammatory marker testing in 2014; 83 761 (61.2%) had a single inflammatory marker at the index date, and 53 200 (38.8%) had multiple inflammatory markers. For ‘any relevant disease’, small differences were seen between the three tests; AUC ranged from 0.659 to 0.682. CRP had the highest overall AUC, largely because of marginally superior performance in infection (AUC CRP 0.617, versus ESR 0.589, P<0.001). Adding a second test gave limited improvement in the AUC for relevant disease (CRP 0.682, versus CRP plus ESR 0.688, P<0.001); this is of debatable clinical significance. The NPV for any single inflammatory marker was 94% compared with 94.1% for multiple negative tests.

Conclusion

Testing multiple inflammatory markers simultaneously does not increase ability to rule out disease and should generally be avoided. CRP has marginally superior diagnostic accuracy for infections, and is equivalent for autoimmune conditions and cancers, so should generally be the first-line test.

Predictive value of inflammatory markers for cancer diagnosis in primary care: a prospective cohort study using electronic health records

Background

Early identification of cancer in primary care is important and challenging. This study examined the diagnostic utility of inflammatory markers (C-reactive protein, erythrocyte sedimentation rate and plasma viscosity) for cancer diagnosis in primary care.

Methods

Cohort study of 160,000 patients with inflammatory marker testing in 2014, plus 40,000 untested matched controls, using Clinical Practice Research Datalink (CPRD), with Cancer Registry linkage. Primary outcome was one-year cancer incidence.

Results

Primary care patients with a raised inflammatory marker have a one-year cancer incidence of 3.53% (95% CI 3.37–3.70), compared to 1.50% (1.43–1.58) in those with normal inflammatory markers, and 0.97% (0.87–1.07) in untested controls. Cancer risk is greater with higher inflammatory marker levels, with older age and in men; risk rises further when a repeat test is abnormal but falls if it normalises. Men over 50 and women over 60 with raised inflammatory markers have a cancer risk which exceeds the 3% NICE threshold for urgent investigation. Sensitivities for cancer were 46.1% for CRP, 43.6% ESR and 49.7% for PV.

Conclusion

Cancer should be considered in patients with raised inflammatory markers. However, inflammatory markers have a poor sensitivity for cancer and are therefore not useful as ‘rule-out’ test.

C-reactive protein and neutrophil count laboratory test requests from primary care: what is the demand and would substitution by point-of-care technology be viable?

AIMS : C-reactive protein (CRP) and neutrophil count (NC) are important diagnostic indicators of inflammation. Point-of-care (POC) technologies for these markers are available but rarely used in community settings in the UK. To inform the potential for POC tests, it is necessary to understand the demand for testing. We aimed to describe the frequency of CRP and NC test requests from primary care to central laboratory services, describe variability between practices and assess the relationship between the tests.

METHODS

We described the number of patients with either or both laboratory tests, and the volume of testing per individual and per practice, in a retrospective cohort of all adults in general practices in Oxfordshire, 2014-2016.

RESULTS

372 017 CRP and 776 581 NC tests in 160 883 and 275 093 patients, respectively, were requested from 69 practices. CRP was tested mainly in combination with NC, while the latter was more often tested alone. The median (IQR) of CRP and NC tests/person tested was 1 (1-2) and 2 (1-3), respectively. The median (IQR) tests/practice/week was 36 (22-52) and 72 (50-108), and per 1000 persons registered/practice/week was 4 (3-5) and 8 (7-9), respectively. The median (IQR) CRP and NC concentrations were 2.7 (0.9-7.9) mg/dL and 4.1 (3.1-5.5)×10⁹/L, respectively.

CONCLUSIONS

The high demand for CRP and NC testing in the community, and the range of results falling within the reportable range for current POC technologies highlight the opportunity for laboratory testing to be supplemented by POC testing in general practice.

Beyond accuracy: hidden motives in diagnostic testing

BACKGROUND

Diagnostic decision-making is usually disease-focussed and intended to examine the patient's medical condition accurately. But diagnostic interventions may serve further purposes that are not yet fully understood.

OBJECTIVE

To explore GPs' diagnostic behaviour not related to confirming or refuting a specific disease.

METHODS

We recorded 295 primary care consultations in 12 practices. One hundred thirty-four consultations comprised at least one diagnostic episode. GPs were asked to reflect on their own diagnostic thinking in interviews for every single case. Qualitative and quantitative analyses were applied with focus on the GPs' cognitive processes during diagnostic decision-making.

RESULTS

Primary care physicians clearly stated that they requested some tests for other reasons than diagnosing disease. A feeling of uncertainty stimulated diagnostic procedures aiming to regulate the anticipation of regret. We identified patients' reassurance, patients' requests and strategic issues as further motives for diagnostic actions.

CONCLUSION

Besides focussing on disease in the diagnostic process, emotional and strategic goals are hidden motives that play a critical role in clinical decision-making. They might even represent an initial factor in a cascade of interventions leading to overdiagnosis. How GPs might control these influences provides an important aspect for further research, practice and teaching.

Variation in diagnostic test requests and outcomes: a preliminary metric for OpenPathology.net

Efforts to reduce healthcare costs have led to the development of metrics to identify unwarranted variation in care. Previous work assessing diagnostic tests is limited, despite their substantial contribution to expenditure. We explored C-reactive Protein (CRP) and Erythrocyte Sedimentation Rate (ESR) tests ordered across Oxfordshire NHS General Practices, and the proportion of tests that yielded an abnormal result, and identified practices that had a proportion of abnormal CRP and ESR results 3 standard deviations below the mean. We estimated the adjusted average proportion of abnormal CRP and ESR tests that yielded abnormal results from each practice, after adjusting for differences in practice populations. These proportions were plotted against the total CRP and ESR requests per practice. We constructed funnel plots to identify practices 3 standard deviations below the mean proportion of abnormal CRP and ESR tests. We analysed 143,745 CRP and 30,758 ESR requests from 69 practices. Twelve (17%) and 7 (10%) practices were more than 3 standard deviations below the mean for CRP and ESR testing respectively. Two practices (3%) were below the 99.8% limit for both CRP and ESR ordering. Variation in the proportion of tests with an abnormal result shows promise for auditing variation in care.

What do tests do for doctors? A qualitative study of blood testing in UK primary care

BACKGROUND

Rates of blood testing are rising with significant geographical variability. Most research into diagnostic testing focuses on the role of tests in diagnostic decision-making.

OBJECTIVE

The aim of this study was to explore the non-medical motives for blood testing by considering what tests do for doctors, through qualitative interviews with general practitioners (GPs).

METHODS

We undertook 23 in-depth semi-structured interviews with UK GPs. Reasons for performing recent inflammatory marker blood tests were explored by reviewing GPs pathology inboxes to ground discussions in real-life clinical practice. Interviews were transcribed verbatim and analysed using a grounded theory approach.

RESULTS

Blood tests offer doctors a tool to manage uncertainty; within a context of increased litigation, risk aversion and reduced continuity of care. Tests can also be offered as a 'gift' for patients, a way to be seen to be 'doing something'; in the social context of time pressures and perceived patient pressures. There was a tension however. On the one hand, doctors talked about using tests for reassurance and as a 'gift' offering 'truth'. Yet paradoxically, they also discussed the challenges of uncertainty and anxiety from inconclusive test results.

CONCLUSION

Our study emphasises that defining 'unnecessary' blood testing may not be as simple as determining medical criteria for testing; psychosocial reasons may be equally valid and interlinked. Further research is needed to help GPs manage uncertainty within the context of a risk averse society, and to explore the congruence and dissonance between doctors' and patients' perceptions of testing.