Factors influencing the diagnostic accuracy of the rapid influenza antigen detection test (RIADT): a cross-sectional study.

OBJECTIVE: To evaluate the diagnostic accuracy of the rapid influenza antigen detection test (RIADT) and determine which symptoms are relevant to results. DESIGN: Single-centre, cross-sectional study. SETTING: Primary care centre, Tokyo, Japan. PARTICIPANTS: 82 consecutive outpatients presenting with upper respiratory symptoms and fever ≥37°C at any time from symptom onset, between December 2010 and April 2011. MAIN OUTCOME MEASURES: Results of history and physical examination including age, sex, temperature, time of test from symptom onset, vaccination record and current symptoms (sore throat, arthralgia and/or myalgia, headache, chills, cough and/or throat phlegm, nasal discharge) were recorded. The RIADT and a fully automated respiratory virus nucleic acid test (Verigene Respiratory Virus Plus; VRV), the latter being the gold standard, were performed. Patients were divided into four groups: false negative (FN), RIADT- and VRV+; true positive (TP), RIADT+ and VRV+; true negative (TN), RIADT- and VRV-; and false positive, RIADT+ and VRV-. Groups were compared regarding age, sex, temperature, time of test from symptom onset, vaccination record and symptoms. RESULTS: RIADT sensitivity, specificity, positive predictive value and negative predictive value were 72.9% (95% CI 61.5% to 84.2%), 91.3% (79.7% to 102.8%), 95.6% (89.5% to 101.6%) and 56.8% (40.8% to 72.7%), respectively. Time from symptom onset to test was shorter for the FN group than the TP group (p=0.009). No significant differences were detected for the other factors assessed. Results revealed higher temperatures for FN than TN patients (p=0.043), and more FN than TN patients had chills (p=0.058). CONCLUSIONS: The RIADT sensitivity was low, due to early administration of the test. In the epidemic season, the RIADT should not be used for suspected influenza until 12 h after symptom onset. A positive RIADT firmly supports the influenza diagnosis; a negative result does not confirm its absence. High fever and chills might indicate influenza, but additional tests are sometimes necessary.

Near point-of-care administration by the attending physician of the rapid influenza antigen detection immunochromatography test and the fully automated respiratory virus nucleic acid test: contribution to patient management.

Rapid influenza antigen detection tests (RIADTs) using immunochromatography are the most readily available tools for the diagnosis and management of influenza. This study was designed to assess whether near point-of-care administration by primary care physicians of the RIADT and a fully automated respiratory virus nucleic acid test (Verigene Respiratory Virus Plus®; RV+) would contribute to improved patient management. When viral culture and RT-PCR/bi-directional sequencing were used as the gold standard, sensitivities and specificities for RIADT and RV+ were 58.3% and 90.9%, and 97.2% and 100%, respectively. Within 12 hours from onset of fever, sensitivities were 44.4% and 94.4%, respectively, for RIADT and RV+. In clinical situations where a higher-sensitivity test is needed, such as during pre-admission evaluations, for testing of hospital employees during the prodromal phase of infection, during the therapeutic decision-making process, and during outbreaks, we suggest that patients testing negative by the RIADT can be reassessed with the RV+ test to achieve maximal diagnostic accuracy.

[Clinical analysis of mortality in elderly patients with community-acquired pneumonia].

AIM: Community-acquired pneumonia remains a common and serious disease for elderly persons. The incidence and mortality rates of pneumonia are higher in the elderly. We analyzed the mortality and prognostic factors in 200 elderly patients with community-acquired pneumonia. METHODS: The subjects were 200 elderly patients aged 65 years or older who needed hospitalization after initial visit to Geriatric Medicine, Juntedo Tokyo Koto Geriatric Medical Center, between January 2005 and December 2006. The subjects were divided into two groups, those who died, and those who survived on admission, we examined mortality rates and compared the background, underlying disease, laboratory data, chest X-ray findings, severity classification using A-DROP, between the two groups. RESULTS: The mortality rate was 15.0%. Circulating diseases, cerebrovacscular diseases and dementia were the most common underlying diseases. It took a longer period to enter the hospital in the cases that died. In laboratory findings, total protein, serum albumin and percutaneous oxygen saturation were lower, and BUN was higher in the fatality group. There were many more patients who had extending infiltration shadow on chest X-ray films and severe condition on A-DROP classification in the fatality group. CONCLUSIONS: We concluded that delay of diagnosis and treatment, dehydration, low levels of protein and albumin were important prognostic factors. The extent of infiltration shadow in chest X-ray findings was also important. A-DROP might be useful for estimating the prognosis in elderly patients with community-acquired pneumonia. We should consider the prognostic factors and severity at the initial stage when treating elderly patients with pneumonia.

[Causes of death in hospitalized elderly patients].

AIM: The Juntendo Tokyo Koto Geriatric Medical Center (JTKGMC) is a community hospital catering for the health care needs of senior citizens, and 37.5% (120 beds) of its beds are psychiatric beds mostly for those with cognitive impairment. The purpose of this study was to analyze cause of death in a hospital like ours with its particular case mix. METHODS: All patients who passed away in our hospital between June 1st 2002 and November 30th 2007 were surveyed with regard to their age distribution and causes of death were analyzed and compared with available national statistics. RESULTS: The over 65 age group accounted for 93.5% of the total and consisted of 815 patients, including 461 men (56.6%) and 354 women (43.4%). The most common cause of death was malignant neoplasm, followed by pneumonia, cardiovascular diseases, cerebrovascular accidents, and renal failure. Among those who died from the primary disease diagnosed on admission, malignancy was most common (288 cases, 61.3%), followed by pneumonia, cerebrovascular accidents, cardiovascular diseases and renal failure. As for those who died from non-primary diagnosis on admission (patients dying due to any condition, not the direct reason of their admission), pneumonia was the most common diagnosis on admission (95 cases, 27.5%), followed by cardiovascular diseases, malignant neoplasm, sepsis and renal failure. In the general wards, above half of those who died due to the primary cause of admission was malignant neoplasm. On the other hand, 1/4 of those who died from causes other than the primary diagnosis on admission was pneumonia. In the mental health wards the most common cause of death due to the primary diagnosis was malignant neoplasm, followed by dementia of Alzheimer's type. The most common cause of death other than the primary reason for admission was pneumonia. More non-primary diagnosis deaths occurred in the mental health wards than in the general wards. CONCLUSION: In our hospital, malignancy and pneumonia were the most common causes of death, rather than cerebrovascular or cardiovascular diseases, but otherwise, the ranking order of the causes of death was very similar to those in other areas of Japan. Causes of the both in our hospital were closely linked with the high incidence of in-hospital mortality in Japan, accounting for 80% of all deaths. Although the case mix of our in-patients is influenced by a particular distribution of health care institutions and nursing care facilities in our catchment area for secondary care, the study demonstrated that our geriatric service responds to the needs of a wide spectrum of indications suffered by elderly citizens at the end of their life.