A prediction rule for elderly primary-care patients with lower respiratory tract infections

Prognostic factors and prediction models for hospitalisation and all-cause mortality in adults presenting to primary care with a lower respiratory tract infection: a systematic review

OBJECTIVE

To identify and synthesise relevant existing prognostic factors (PF) and prediction models (PM) for hospitalisation and all-cause mortality within 90 days in primary care patients with acute lower respiratory tract infections (LRTI).

DESIGN

Systematic review.

METHODS

Systematic searches of MEDLINE, Embase and the Cochrane Library were performed. All PF and PM studies on the risk of hospitalisation or all-cause mortality within 90 days in adult primary care LRTI patients were included. The risk of bias was assessed using the Quality in Prognostic Studies tool and Prediction Model Risk Of Bias Assessment Tool tools for PF and PM studies, respectively. The results of included PF and PM studies were descriptively summarised.

RESULTS

Of 2799 unique records identified, 16 were included: 9 PF studies, 6 PM studies and 1 combination of both. The risk of bias was judged high for all studies, mainly due to limitations in the analysis domain. Based on reported multivariable associations in PF studies, increasing age, sex, current smoking, diabetes, a history of stroke, cancer or heart failure, previous hospitalisation, influenza vaccination (negative association), current use of systemic corticosteroids, recent antibiotic use, respiratory rate ≥25/min and diagnosis of pneumonia were identified as most promising candidate predictors. One newly developed PM was externally validated (c statistic 0.74, 95% CI 0.71 to 0.78) whereas the previously hospital-derived CRB-65 was externally validated in primary care in five studies (c statistic ranging from 0.72 (95% CI 0.63 to 0.81) to 0.79 (95% CI 0.65 to 0.92)). None of the PM studies reported measures of model calibration.

CONCLUSIONS

Implementation of existing models for individualised risk prediction of 90-day hospitalisation or mortality in primary care LRTI patients in everyday practice is hampered by incomplete assessment of model performance. The identified candidate predictors provide useful information for clinicians and warrant consideration when developing or updating PMs using state-of-the-art development and validation techniques.

PROSPERO REGISTRATION NUMBER

CRD42022341233.

Predicting adverse outcomes in adults with a community-acquired lower respiratory tract infection: a protocol for the development and validation of two prediction models for (i) all-cause hospitalisation and mortality and (ii) cardiovascular outcomes

BACKGROUND

Community-acquired lower respiratory tract infections (LRTI) are common in primary care and patients at particular risk of adverse outcomes, e.g., hospitalisation and mortality, are challenging to identify. LRTIs are also linked to an increased incidence of cardiovascular diseases (CVD) following the initial infection, whereas concurrent CVD might negatively impact overall prognosis in LRTI patients. Accurate risk prediction of adverse outcomes in LRTI patients, while considering the interplay with CVD, can aid general practitioners (GP) in the clinical decision-making process, and may allow for early detection of deterioration. This paper therefore presents the design of the development and external validation of two models for predicting individual risk of all-cause hospitalisation or mortality (model 1) and short-term incidence of CVD (model 2) in adults presenting to primary care with LRTI.

METHODS

Both models will be developed using linked routine electronic health records (EHR) data from Dutch primary and secondary care, and the mortality registry. Adults aged ≥ 40 years with a GP-diagnosis of LRTI between 2016 and 2019 are eligible for inclusion. Relevant patient demographics, medical history, medication use, presenting signs and symptoms, and vital and laboratory measurements will be considered as candidate predictors. Outcomes of interest include 30-day all-cause hospitalisation or mortality (model 1) and 90-day CVD (model 2). Multivariable elastic net regression techniques will be used for model development. During the modelling process, the incremental predictive value of CVD for hospitalisation or all-cause mortality (model 1) will also be assessed. The models will be validated through internal-external cross-validation and external validation in an equivalent cohort of primary care LRTI patients.

DISCUSSION

Implementation of currently available prediction models for primary care LRTI patients is hampered by limited assessment of model performance. While considering the role of CVD in LRTI prognosis, we aim to develop and externally validate two models that predict clinically relevant outcomes to aid GPs in clinical decision-making. Challenges that we anticipate include the possibility of low event rates and common problems related to the use of EHR data, such as candidate predictor measurement and missingness, how best to retrieve information from free text fields, and potential misclassification of outcome events.

Patients receiving a high burden of antibiotics in the community in Spain: a cross-sectional study

Some patients in the community receive a high burden of antibiotics. We aimed at describing the characteristics of these patients, antibiotics used, and conditions for which they received antibiotics. We carried out a cross-sectional study. Setting: Thirty Health Primary Care Areas from 12 regions in Spain, covering 5,960,191 inhabitants. Patients having at least 30 packages of antibacterials for systemic use dispensed in 2017 were considered. Main outcome measures: Prevalence of antibiotic use, conditions for which antibiotics were prescribed, clinical characteristics of patients, comorbidities, concomitant treatments, and microbiological isolates. Patient's average age was 70 years; 52% were men; 60% smokers/ex-smokers; 54% obese. Overall, 93% of patients had, at least, one chronic condition, and four comorbidities on average. Most common comorbidities were cardiovascular and/or hypertension (67%), respiratory diseases (62%), neurological/mental conditions (32%), diabetes (23%), and urological diseases (21%); 29% were immunosuppressed, 10% were dead at the time of data collection. Patients received three antibiotic treatments per year, mainly fluoroquinolones (28%), macrolides (21%), penicillins (19%), or cephalosporins (12%). Most frequently treated conditions were lower respiratory tract (infections or prophylaxis) (48%), urinary (27%), and skin/soft tissue infections (11%). Thirty-five percent have been guided by a microbiological diagnosis, being Pseudomonas aeruginosa (30%) and Escherichia coli (16%) the most frequent isolates. In conclusion, high antibiotic consumers in the community were basically elder, with multimorbidity and polymedication. They frequently received broad-spectrum antibiotics for long periods of time. The approach to infections in high consumers should be differentiated from healthy patients receiving antibiotics occasionally.

Utilisation of healthcare services for respiratory tract infections in patients with and without diabetes in Qatar: a cross-sectional study

OBJECTIVE

People with diabetes mellitus have a high risk of acquiring respiratory tract infections (RTIs), yet little is known about their utilisation of healthcare services compared with people without diabetes. This study aimed to compare the utilisation of healthcare services for RTIs between individuals with and without diabetes attending primary healthcare centres (PHCCs) in Qatar.

DESIGN

A retrospective cross-sectional study was conducted using an electronic database of all individuals who had a diagnosis of RTI.

SETTING

PHCCs in Qatar from July 2015 to December 2017.

PARTICIPANTS

Participants in the study were all adult individuals (aged ≥18 years) who visited the primary healthcare facilities and were diagnosed with an RTI during the study period.

PRIMARY AND OUTCOME MEASURES

For each participant, visits to the healthcare facility, antibiotic use and use of other medications were extracted from the electronic database and compared between participants with and without a diabetes diagnosis.

RESULTS

A total of 32 857 participants were included, of whom 7407 (22.5%) had a diabetes diagnosis. Results from a negative binomial regression indicate that diabetes diagnosis was significantly associated with increased visits to the healthcare facility (incidence rate ratio (IRR) 1.10, 95% CI 1.076 to 1.134, p<0.001), antibiotic use (IRR 1.09, 95% CI 1.046 to 1.145, p<0.001) and use of other medications (IRR 1.11, 95% CI 1.078 to 1.143, p<0.001).

CONCLUSIONS

A diabetes diagnosis among patients with RTI was associated with higher utilisation of healthcare services. Given the added costs to the healthcare system, prevention of diabetes will have additional benefits to the healthcare system, apart from diabetes-associated costs alone.

Guideline for Antibiotic Use in Adults with Community-acquired Pneumonia

Community-acquired pneumonia is common and important infectious disease in adults. This work represents an update to 2009 treatment guideline for community-acquired pneumonia in Korea. The present clinical practice guideline provides revised recommendations on the appropriate diagnosis, treatment, and prevention of community-acquired pneumonia in adults aged 19 years or older, taking into account the current situation regarding community-acquired pneumonia in Korea. This guideline may help reduce the difference in the level of treatment between medical institutions and medical staff, and enable efficient treatment. It may also reduce antibiotic resistance by preventing antibiotic misuse against acute lower respiratory tract infection in Korea.

The risk of community-acquired pneumonia among 9803 patients with coeliac disease compared to the general population: a cohort study

BACKGROUND

Patients with coeliac disease are considered as individuals for whom pneumococcal vaccination is advocated.

AIM

To quantify the risk of community-acquired pneumonia among patients with coeliac disease, assessing whether vaccination against streptococcal pneumonia modified this risk.

METHODS

We identified all patients with coeliac disease within the Clinical Practice Research Datalink linked with English Hospital Episodes Statistics between April 1997 and March 2011 and up to 10 controls per patient with coeliac disease frequency matched in 10-year age bands. Absolute rates of community-acquired pneumonia were calculated for patients with coeliac disease compared to controls stratified by vaccination status and time of diagnosis using Cox regression in terms of adjusted hazard ratios (HR).

RESULTS

Among 9803 patients with coeliac disease and 101 755 controls, respectively, there were 179 and 1864 first community-acquired pneumonia events. Overall absolute rate of pneumonia was similar in patients with coeliac disease and controls: 3.42 and 3.12 per 1000 person-years respectively (HR 1.07, 95% CI 0.91-1.24). However, we found a 28% increased risk of pneumonia in coeliac disease unvaccinated subjects compared to unvaccinated controls (HR 1.28, 95% CI 1.02-1.60). This increased risk was limited to those younger than 65, was highest around the time of diagnosis and was maintained for more than 5 years after diagnosis. Only 26.6% underwent vaccination after their coeliac disease diagnosis.

CONCLUSIONS

Unvaccinated patients with coeliac disease under the age of 65 have an excess risk of community-acquired pneumonia that was not found in vaccinated patients with coeliac disease. As only a minority of patients with coeliac disease are being vaccinated there is a missed opportunity to intervene to protect these patients from pneumonia.

Risk factors for hospital admission in the 28 days following a community-acquired pneumonia diagnosis in older adults, and their contribution to increasing hospitalisation rates over time: a cohort study

OBJECTIVES

To determine factors associated with hospitalisation after community-acquired pneumonia (CAP) among older adults in England, and to investigate how these factors have contributed to increasing hospitalisations over time.

DESIGN

Cohort study.

SETTING

Primary and secondary care in England.

POPULATION

39,211 individuals from the Clinical Practice Research Datalink, who were eligible for linkage to Hospital Episode Statistics and mortality data, were aged ≥ 65 and had at least 1 CAP episode between April 1998 and March 2011.

MAIN OUTCOME MEASURES

The association between hospitalisation within 28 days of CAP diagnosis (a 'post-CAP' hospitalisation) and a wide range of comorbidities, frailty factors, medications and vaccinations. We examined the role of these factors in post-CAP hospitalisation trends. We also looked at trends in post-CAP mortality and length of hospitalisation over the study period.

RESULTS

14 comorbidities, 5 frailty factors and 4 medications/vaccinations were associated with hospitalisation (of 18, 12 and 7 considered, respectively). Factors such as chronic lung disease, severe renal disease and diabetes were associated with increased likelihood of hospitalisation, whereas factors such as recent influenza vaccination and a recent antibiotic prescription decreased the odds of hospitalisation. Despite adjusting for these and other factors, the average predicted probability of hospitalisation after CAP rose markedly from 57% (1998-2000) to 86% (2009-2010). Duration of hospitalisation and 28-day mortality decreased over the study period.

CONCLUSIONS

The risk factors we describe enable identification of patients at increased likelihood of post-CAP hospitalisation and thus in need of proactive case management. Our analyses also provide evidence that while comorbidities and frailty factors contributed to increasing post-CAP hospitalisations in recent years, the trend appears to be largely driven by changes in service provision and patient behaviour.

Characteristics and prognosis of near-fatal asthma exacerbations

BACKGROUND

Asthma remains a major public health concern because of its high prevalence and the costs it generates. Near-fatal asthma (NFA) episodes represent the most severe forms of the disease after fatal asthma with significant variations in their incidence between different populations.

OBJECTIVE

To analyze the episodes of NFA over a period of 11 years in the hospital.

METHODS

The authors retrospectively reviewed all admissions due to asthma exacerbation in our hospital between 2000 and 2010 for patients over 18 years of age.

RESULTS

The study included 400 NFA episodes of 285 patients (74% women; mean age 66 years). Of these patients, 228 (80%) had a single episode of NFA and 57 had more than 1 episode during the study period. The authors observed no clear upward or downward trend during the study period. Readmitted patients had more comorbidities, poorer lung function, more severe forms of asthma and more admissions in the year before the index admission. There was a mortality rate of 3.1%. More than 20% of patients were not given controller treatment and more than 40% of patients were not treated with inhaled corticosteroids (ICS).

CONCLUSIONS

NFA episodes are still prevalent in the population of patients with asthma. Reasons for this could be related to improper management in the stable phase, as suggested by the low rate of patients treated with ICS. It also seems necessary to optimize patient management during hospitalization because stays appear prolonged in comparison with studies in other countries.

Incidence of severe tracheobronchitis and pneumonia in laryngectomized patients: a retrospective clinical study and a European-wide survey among head and neck surgeons

Laryngectomized patients, lacking conditioning of the breathing air in the upper respiratory tract, have reported considerable pulmonary complaints. It is assumed that these patients also run a higher risk of developing severe respiratory infections. Unfortunately, there is little scientific information available about the occurrence of respiratory infections and related health costs in these patients with and without the use of an HME. Therefore, the occurrence of respiratory infections in laryngectomized patients was investigated in the Netherlands Cancer Institute and by means of a survey among head and neck oncology surgeons throughout Europe. The number of tracheobronchitis and/or pneumonia events was retrospectively scored between 1973 and 2013 in medical records of 89 laryngectomized patients treated in our institute. To assess expert experiences and opinions regarding these pulmonary problems, a study-specific survey was developed. The survey was sent by email to head and neck surgeons from ten different countries. In the medical record study, an average of 0.129 respiratory infections per patient/year was found in non-HME users and 0.092 in HME users. In the survey (response rate HN surgeons 20 %; countries 90 %) 0.285 episodes per patient/year in non-HME users was statistically higher than the 0.066 episodes per patient/year in HME users. The average mortality in the HME user group per entire career of each physician was estimated at 0.0045, and for the non-HME user group this was 0.0152. There is a tendency that the number of tracheobronchitis and pneumonia episodes in non-HME users is higher than in HME users.

Incidence of community-acquired lower respiratory tract infections and pneumonia among older adults in the United Kingdom: a population-based study

Community-acquired lower respiratory tract infections (LRTI) and pneumonia (CAP) are common causes of morbidity and mortality among those aged ≥65 years; a growing population in many countries. Detailed incidence estimates for these infections among older adults in the United Kingdom (UK) are lacking. We used electronic general practice records from the Clinical Practice Research Data link, linked to Hospital Episode Statistics inpatient data, to estimate incidence of community-acquired LRTI and CAP among UK older adults between April 1997-March 2011, by age, sex, region and deprivation quintile. Levels of antibiotic prescribing were also assessed. LRTI incidence increased with fluctuations over time, was higher in men than women aged ≥70 and increased with age from 92.21 episodes/1000 person-years (65-69 years) to 187.91/1000 (85-89 years). CAP incidence increased more markedly with age, from 2.81 to 21.81 episodes/1000 person-years respectively, and was higher among men. For both infection groups, increases over time were attenuated after age-standardisation, indicating that these rises were largely due to population aging. Rates among those in the most deprived quintile were around 70% higher than the least deprived and were generally higher in the North of England. GP antibiotic prescribing rates were high for LRTI but lower for CAP (mostly due to immediate hospitalisation). This is the first study to provide long-term detailed incidence estimates of community-acquired LRTI and CAP in UK older individuals, taking person-time at risk into account. The summary incidence commonly presented for the ≥65 age group considerably underestimates LRTI/CAP rates, particularly among older individuals within this group. Our methodology and findings are likely to be highly relevant to health planners and researchers in other countries with aging populations.

Severity assessment for lower respiratory tract infections: potential use and validity of the CRB-65 in primary care

AIMS

To explore the potential use of the CRB-65 rule (based on Confusion, Respiratory rate, Blood pressure and age >65 years) in adults with lower respiratory tract infection (LRTI) in primary care.

METHODS

Primary care clinicians in 13 European countries recorded antibiotic treatment and clinical features for adults with LRTI. Patients recorded daily symptoms. Multilevel regression models determined the association between an elevated CRB-65 score and prolonged moderately severe symptoms, hospitalisation, and time to recovery. Sensitivity analyses used zero imputation.

RESULTS

Respiratory rate and blood pressure were recorded in 22.7% and 31.9% of patients, respectively. A total of 2,690 patients completed symptom diaries. The CRB-65 could be calculated for 339 (12.6%). A score of >1 was not significantly associated with prolonged moderately severe symptoms (odds ratio (OR) 0.42, 95% CI 0.04 to 4.19) or hospitalisations (OR 3.12, 95% CI 0.16 to 60.24), but was associated with prolonged time to self-reported recovery when using zero imputation (hazard ratio (HR) 0.75, 95% CI 0.64 to 0.88).

CONCLUSIONS

Respiratory rate and blood pressure are infrequently measured in adults with LRTI. We found no evidence to support using the CRB-65 rule in the assessment of LRTI in primary care. However, it is unclear whether it is of value if used only in patients where the primary care clinician suspects pneumonia.

Predicting benign course and prolonged illness in lower respiratory tract infections: a 13 European country study

BACKGROUND

Clinicians and patients are often uncertain about the likely clinical course of community-acquired lower respiratory tract infection (LRTI) in individual patients. We therefore set out to develop a prediction rule to identify patients at risk of prolonged illness and those with a benign course.

METHODS

We determined which signs and symptoms predicted prolonged illness (moderately bad symptoms lasting >3 weeks after consultation) in 2690 adults presenting in primary care with LRTI in 13 European countries by using multilevel modelling.

RESULTS

212 (8.1%) patients experienced prolonged illness. Illness that had lasted >5 days at the time of presentation, >1 episode of cough in the preceding year, chronic use of inhaled pulmonary medication and diarrhoea independently predicted prolonged illness. Applying a rule based on these four variables, 3% of the patients with ≤ 1 variable present (n = 955, 37%) had prolonged illness. Patients with all four variables present had a 30% chance of prolonged illness (n = 71, 3%).

CONCLUSIONS

Most patients with acute cough (>90%) recover within 3 weeks. A prediction rule containing four clinical items had predictive value for the risk of prolonged illness, but given its imprecision, appeared to have little clinical utility. Patients should be reassured that they are most likely to recover within three weeks and advised to re-consult if their symptoms persist beyond that period.

Guidelines for the management of adult lower respiratory tract infections--summary

This document is an update of Guidelines published in 2005 and now includes scientific publications through to May 2010. It provides evidence-based recommendations for the most common management questions occurring in routine clinical practice in the management of adult patients with LRTI. Topics include management outside hospital, management inside hospital (including community-acquired pneumonia (CAP), acute exacerbations of COPD (AECOPD), acute exacerbations of bronchiectasis) and prevention. The target audience for the Guideline is thus all those whose routine practice includes the management of adult LRTI.

Guidelines for the management of adult lower respiratory tract infections--full version

This document is an update of Guidelines published in 2005 and now includes scientific publications through to May 2010. It provides evidence-based recommendations for the most common management questions occurring in routine clinical practice in the management of adult patients with LRTI. Topics include management outside hospital, management inside hospital (including community-acquired pneumonia (CAP), acute exacerbations of COPD (AECOPD), acute exacerbations of bronchiectasis) and prevention. Background sections and graded evidence tables are also included. The target audience for the Guideline is thus all those whose routine practice includes the management of adult LRTI.

Validity of British Thoracic Society guidance (the CRB-65 rule) for predicting the severity of pneumonia in general practice: systematic review and meta-analysis

BACKGROUND

The CRB-65 score is a clinical prediction rule that grades the severity of community-acquired pneumonia in terms of 30-day mortality.

AIM

The study sought to validate CRB-65 and assess its clinical value in community and hospital settings.

DESIGN OF STUDY

Systematic review and meta-analysis of validation studies of CRB-65.

METHOD

Medline (1966 to June 2009), Embase (1988 to November 2008), British Nursing Index (BNI) and PsychINFO were searched, using a diagnostic accuracy search filter combined with subject-specific terms. The derived (index) rule was used as a predictive model and applied to all validation studies. Comparison was made between the observed and predicted number of deaths stratified by risk group (low, intermediate, and high) and setting of care (community or hospital). Pooled results are presented as risk ratios (RRs) in terms of over-prediction (RR>1) or under-prediction (RR<1) of 30-day mortality.

RESULTS

Fourteen validation studies totalling 397 875 patients are included. CRB-65 performs well in hospitalised patients, particularly in those classified as intermediate (RR 0.91, 95% confidence interval [CI] = 0.71 to 1.17) or high risk (RR 1.01, 95% CI = 0.87 to 1.16). In community settings, CRB-65 over-predicts the probability of 30-day mortality across all strata of predicted risk, low (RR 9.41, 95% CI = 1.75 to 50.66), intermediate (RR 4.84, 95% CI = 2.61 to 8.69), and high (RR 1.58, 95% CI = 0.59 to 4.19).

CONCLUSION

CRB-65 performs well in stratifying severity of pneumonia and resultant 30-day mortality in hospital settings. In community settings, CRB-65 appears to over-predict the probability of 30-day mortality across all strata of predicted risk. Caution is needed when applying CRB-65 to patients in general practice.

The value of prognostic indices for pneumonia

One of the most important decisions in the management of community-acquired pneumonia is deciding the care site, which affects morbidity, mortality, and costs. Clinical judgment alone is difficult and imprecise. The Pneumonia Severity Index score and the CURB-65 (confusion, urea nitrogen, respiratory rate, blood pressure, 65 years of age and older) score are validated prognostic indices to predict mortality, and they can identify low-risk patients who may be eligible for outpatient management. However, limitations of the scoring systems preclude their isolated use, and they can only be recommended as an aid to guide hospital admission decisions. The Pneumonia Severity Index score is slightly better at identifying the lowest risk patients, whereas CURB-65 is much simpler to use. As an adjunct to clinical judgment, we consider CURB-65 to be the most useful prognostic index for identifying low-risk patients.

CRP gene variation and risk of community-acquired pneumonia

BACKGROUND AND OBJECTIVE

CRP has several potentially antibacterial effects, and variation in the CRP gene is known to influence CRP levels. Whether this variation influences risk of infection, and hence whether CRP has anti-infective activity in humans, is uncertain.

METHODS

We evaluated a series of haplotype-tagging single nucleotide polymorphisms among 5374 individuals in the Cardiovascular Health Study, a cohort of older adults from four communities, who were followed for community-acquired pneumonia for 12-13 years. Secondarily, we evaluated whether these polymorphisms varied among men in the Health Professionals Follow-up Study who self-reported pneumonia on biennial questionnaires.

RESULTS

There were 581 (507 white and 74 black) Cardiovascular Health Study participants with incident hospitalizations for pneumonia. No single nucleotide polymorphism or haplotypes were associated with risk among white Cardiovascular Health Study participants. Among black participants, the haplotype tagged by A790T was associated with lower risk of incident pneumonia (hazard ratio 0.5; 95% confidence interval: 0.3-0.9) and with higher CRP levels. In Health Professionals Follow-up Study, a separate haplotype was associated with less frequent self-reported pneumonia but not with circulating CRP levels.

CONCLUSIONS

Some genetic variants in CRP may be associated with risk of pneumonia, but haplotypes associated with risk are variably associated with baseline CRP levels. If CRP is a relevant component of innate immunity in humans, the inducibility or tissue-specificity of expression may be at least as important as chronic circulating levels.

Validation, updating and impact of clinical prediction rules: a review

OBJECTIVE

To provide an overview of the research steps that need to follow the development of diagnostic or prognostic prediction rules. These steps include validity assessment, updating (if necessary), and impact assessment of clinical prediction rules.

STUDY DESIGN AND SETTING

Narrative review covering methodological and empirical prediction studies from primary and secondary care.

RESULTS

In general, three types of validation of previously developed prediction rules can be distinguished: temporal, geographical, and domain validations. In case of poor validation, the validation data can be used to update or adjust the previously developed prediction rule to the new circumstances. These update methods differ in extensiveness, with the easiest method a change in model intercept to the outcome occurrence at hand. Prediction rules -- with or without updating -- showing good performance in (various) validation studies may subsequently be subjected to an impact study, to demonstrate whether they change physicians' decisions, improve clinically relevant process parameters, patient outcome, or reduce costs. Finally, whether a prediction rule is implemented successfully in clinical practice depends on several potential barriers to the use of the rule.

CONCLUSION

The development of a diagnostic or prognostic prediction rule is just a first step. We reviewed important aspects of the subsequent steps in prediction research.

Prognosis of primary care patients aged 80 years and older with lower respiratory tract infection

BACKGROUND

Predictors for a complicated course of a lower respiratory tract infection (LRTI) episode among patients aged > or =80 years are unknown.

AIM

To determine prognostic factors for hospital admission or death within 30 days after first onset of LRTI among primary care patients aged > or =80 years.

DESIGN OF STUDY

Retrospective cohort study.

SETTING

Utrecht General Practitioner Research Network.

METHOD

Data were obtained using the computerised database of the research network over the years 1997 to 2003. Multivariable logistic regression analysis was applied to estimate the independent association of predictors with 30-day hospitalisation or death.

RESULTS

In all, 860 episodes of LRTI were observed in 509 patients; 13% of patients were hospitalised or died within 30 days. Type of LRTI, diabetes, use of oral glucocorticoids, use of antibiotics in the previous month, and hospitalisation in the previous 12 months were independently associated with the combined outcome. Patients with insulin-dependent diabetes mellitus had a greater risk of 30-day hospitalisation or death compared with patients with non-insulin-dependent diabetes.

CONCLUSION

Independent of age, serious comorbidity - notably the presence of insulin-dependent diabetes or exacerbation of chronic obstructive pulmonary disease requiring oral glucocorticoids - increases the risk for complications, including hospital admissions, in patients aged > or =80 years with an LRTI.

Prediction of complicated lower respiratory tract infections in older patients with diabetes

BACKGROUND

Patients with diabetes have an elevated risk of developing complicated lower respiratory tract infections (LRTIs). However, up until now, GPs have not had the tools to assess individual risks.

AIM

To assess the applicability of an existing prediction rule for complicated LRTI among patients with diabetes.

DESIGN OF STUDY

Retrospective cohort study.

SETTING

The Utrecht GP Research Network.

METHOD

An existing rule that was used estimates the risk of 30-day hospitalisation or death following an episode of LRTI. Predictors were exacerbation of chronic obstructive pulmonary disease, or pneumonia, increasing age, heart failure, number of hospitalisations in the previous year, use of antibiotics in the previous month, diabetes medication, and prednisone use. Discriminative capacity of the rule was estimated in patients with diabetes. Other potential predictors from the original study were examined, to test for a potentially improved model.

RESULTS

Of 445 episodes of LRTI in patients with diabetes, 68 had an outcome of hospitalisation or death within 30 days of diagnosis of LRTI (15.3%). Results showed good reliability of the model (goodness of fit test P=0.16) and discriminative properties (area under the receiver operating characteristic curve: 0.79, 95% confidence interval=0.73 to 0.86). No other predictors could be added. Patients with a lower-risk assignment (score<or=2) had a probability of 5.2%, and those with higher risks (score>or=7) had a probability of 36.6% for the composite endpoint of hospitalisation or death within 30 days of diagnosis of LRTI.

CONCLUSION

The use of a prediction rule may help GPs to assess the risk of hospitalisation or death in patients with diabetes who have an episode of LRTI.

A transgenic mouse with vascular endothelial over-expression of the non-muscle myosin light chain kinase-2 isoform is susceptible to inflammatory lung injury: role of sexual dimorphism and age

We have generated genetically engineered mice that are uniquely susceptible to lipopolysaccharide (LPS)-induced and mechanical ventilation-induced lung injury in a sex-specific and age-specific manner. These mice express a nonmuscle isoform of the myosin light chain kinase gene (nmMLCK2) targeted to the endothelium. Homozygous mice have significantly reduced fecundity and litter survival until weaning, and they are initially growth delayed but eventually exceed the size of wild-type littermates. Mice at all ages show increased protein transport across the lung barrier; however, the phenotype is most discernible in 8-12-week-old male mice. When subjected to a clinically relevant LPS-induced lung injury model, 8-12-week-old young females and 30-36-week-old males seem to be the most significantly injured group. In contrast, 30-36-week-old males remain the most significantly injured group when mechanically ventilated at high tidal volumes, which is a clinically relevant model of mechanical stress lung injury. These data reveal that nmMLCK2 overexpression in the endothelium exacerbates lung injury in vivo in a sexually dimorphic and age-dependent manner.

Oseltamivir and the risk of influenza-related complications and hospitalizations in patients with diabetes

OBJECTIVE

This subgroup analysis of a retrospective cohort study examined, from a managed care perspective, the risk of influenza-related complications and hospitalizations in patients with diabetes who were prescribed oseltamivir for the treatment of influenza and those who were not prescribed antiviral treatment.

METHODS

Health insurance claims data from the Thomson Healthcare MarketScan Research Database for 6 influenza seasons (October 1-March 31) between 2000 and 2006 were used to identify patients aged >/=18 years with influenza and diabetes. Patients who received a prescription for oseltamivir within 1 day of a diagnosis of influenza were compared with those who received no antiviral treatment. Outcomes included the frequency of pneumonia, respiratory diagnoses, and otitis media and its complications, and rates of hospitalization within 14 days of the diagnosis of influenza. Cox proportional hazards regression was used to determine the relative risk (RR) of influenza-related complications and hospitalizations.

RESULTS

A total of 9090 patients with diabetes and a diagnosis of influenza were identified who met all study criteria. Of these, 2919 (32%) received a prescription for oseltamivir and 6171 (68%) received no antiviral treatment. Patients receiving oseltamivir had a significant 17% reduction in the risk of respiratory illnesses (RR = 0.83; 95% CI, 0.73-0.93) and a 30% reduction in the risk of hospitalization for any reason (RR = 0.70; 95% CI, 0.52-0.94). There were no significant differences between the oseltamivir and control groups in terms of the risks for pneumonia (RR = 0.87; 95% CI, 0.64-1.18), otitis media and its complications (RR = 0.96; 95% CI, 0.48-1.91), or hospitalization for pneumonia (RR = 0.81; 95% CI, 0.41-1.58).

CONCLUSION

In this retrospective study, the risk of influenza-associated respiratory illnesses and the number of hospitalizations for any reason were reduced in patients with diabetes who were prescribed oseltamivir compared with an unmatched group that was not prescribed antiviral therapy.