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1,398 result(s) for "Positive predictive value"
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Validation of Postsurgical Venous Thromboembolism Diagnoses of Patients Undergoing Lower Limb Orthopedic Surgery in the Danish National Patient Registry
Healthcare databases can be a valuable source of epidemiological research regarding postoperative venous thromboembolism (VTE), ie, deep vein thrombosis (DVT) and pulmonary embolism (PE), following orthopedic procedures, but only if the diagnoses are valid. We examined the validity of VTE diagnosis codes in the Danish National Patient Registry (DNPR) by calculating their positive predictive value (PPV) and negative predictive value (NPV) versus actual medical records. We identified patients who had undergone lower limb surgery during the period 2009-2019 at a hospital in the North Denmark Region. Of these, 420 patients had at least one VTE diagnosis registered in the DNPR within 180 days after lower limb surgery. Each patient with a VTE diagnosis was matched with two patients on age and sex, as well as type, location and period of surgery. The entire medical record and diagnostic imaging were reviewed to confirm VTE diagnosis. The overall PPVs was 85.2% (95% CI: 81.5-88.5%) for first time VTE diagnosis following lower limb surgery, 82.6% (95% CI: 77.5-82.8%) for DVT, and 90.3% (95% CI: 84.3-94.6%) for PE. We found improvement in PPV during the study period when stratifying for three periods of the whole period. There were no significant differences when stratifying for sex, age, or surgery site. All negative predictive values were higher than 99%. A total of 113 additional VTE diagnoses were registered among 88 VTE patients during follow-up. Only four of the suspected recurrent VTEs were confirmed to be true recurrent VTEs. The VTE diagnosis codes in the DNPR after lower limb orthopedic surgery were highly valid against the actual medical records, and we observed better PPV over recent years.
Positive Predictive Value of ICD-10 Diagnosis Codes for COVID-19
To examine the positive predictive value (PPV) of International Classification version 10 (ICD-10) diagnosis codes for Coronavirus disease 2019 (COVID-19). Medical record review of all patients assigned a diagnosis code of COVID-19 (DB342A or DB972A) at six Danish departments of infectious diseases from February 27 through May 4, 2020. Confirmed COVID-19 diagnosis was defined as either: 1) definite, a positive polymerase chain reaction (PCR) for severe acute respiratory syndrome Coronavirus 2 (SARS-CoV-2) on a respiratory sample combined with symptoms suggestive of COVID-19: 2) probable, clinical presentation of COVID-19 without detection of SARS-CoV-2 and no alternative diagnoses considered more likely; or 3) possible, clinical presentation of COVID-19 without detection of SARS-CoV-2, and the patient was discharged or deceased before further investigations were carried out. We computed the PPV with 95% confidence intervals (CI) as the number of patients with confirmed (i.e., definite, probable, and possible) COVID-19 divided by the number of patients assigned a diagnosis code for COVID-19. The study included 710 patients with a median age of 61 years (interquartile range [IQR] 47-74) and 285/710 (40%) were female. COVID-19 was confirmed in 706/710 (99%) with 705/710 (99%) categorized as definite, 1/710 (0.1%) as probable, and 0 patients as possible COVID-19. The diagnosis was disproven in 4/710 (0.6%) patients who were hospitalized due to bacterial pneumonia (n = 2), influenza (n = 1), and urinary tract infection (n = 1). The overall PPV for COVID-19 was 99% (95% CI 99-100) and remained consistently high among all subgroups including sex, age groups, calendar period, and stratified by diagnosis code and department of infectious diseases (range 97-100%). The overall PPV of diagnosis codes for COVID-19 in Denmark was high and may be suitable for future registry-based prognosis studies of COVID-19.
Assessment of the Accuracy of Using ICD-10 Codes to Identify Systemic Sclerosis
With the increased use of data from electronic medical records for research, it is important to validate in-patient electronic health records/hospital electronic health records for specific diseases identification using International Classification of Diseases, Tenth Revision ( ) codes. To assess the accuracy of using codes to identify systemic sclerosis (SSc) in the French hospital database. Electronic health record database analysis. The setting of the study's in-patient database was the Toulouse University Hospital, a tertiary referral center (2880 beds) that serves approximately 2.9 million inhabitants. Participants were patients with discharge diagnosis codes of SSc seen at Toulouse University Hospital between January 1, 2010, and December 31, 2017. The main outcome was the positive predictive value (PPV) of discharge diagnosis codes for identifying SSc. The PPVs were calculated by determining the ratio of the confirmed cases found by medical record review to the total number of cases identified by code. Of the 2766 hospital stays, 216 patients were identified by an SSc discharge diagnosis code. Two hundred were confirmed as SSc after medical record review. The overall PPV was 93% (95% CI, 88-95%). The PPV for limited cutaneous SSc was 95% (95% CI, 85-98%). Our results suggest that using codes alone to capture SSc is reliable in The French hospital database.
The Effects of Prior Mammography Screening on the Performance of Breast Cancer Detection in Taiwan
The aim of this study was to investigate the influence of previous mammography screening on the performance of breast cancer detection. The screened women were divided into first-visit and follow-up groups for breast cancer screening. The positive predictive value (PPV), cancer detection rate (CDR), and recall rate were used to evaluate and analyze the overall screening performance among the two groups. Among them, 10,040 screenings (67.2%) were first visits and 4895 screenings (32.8%) were follow-up visits. The proportion of positive screening results for first-visit participants was higher than that for their follow-up counterparts (9.3% vs. 4.0%). A total of 98 participants (74 first-visit and 24 follow-up visit) were confirmed to have breast cancer. The PPV for positive mammography for women who underwent biopsy confirmation was 28.7% overall, reaching 35.8% for the follow-up visit group and 27.0% for the first-visit group. The CDR was 6.6 per 1000 overall, reaching 7.4 per 1000 for first-visit group and 4.9 per 1000 for the follow-up group. The overall recall rate was 7.9%, reaching 9.7% for the first-visit group and 4.2% for the follow-up group. The PPV is improved and the recall rate is decreased if prior mammography images are available for comparison when conducting mammography screening for breast cancer. By this study, we concluded that prior mammography plays an important role for breast cancer screening, while follow-up mammography may increase the diagnostic rate when compared to the prior mammography. We suggest that the public health authority can encourage subjects to undergo screenings in the same health institute where they regularly visit.
The Coronavirus Disease 2019 Spatial Care Path: Home, Community, and Emergency Diagnostic Portals
This research uses mathematically derived visual logistics to interpret COVID-19 molecular and rapid antigen test (RAgT) performance, determine prevalence boundaries where risk exceeds expectations, and evaluate benefits of recursive testing along home, community, and emergency spatial care paths. Mathematica and open access software helped graph relationships, compare performance patterns, and perform recursive computations. Tiered sensitivity/specificity comprise: (T1) 90%/95%; (T2) 95%/97.5%; and (T3) 100%/≥99%, respectively. In emergency medicine, median RAgT performance peaks at 13.2% prevalence, then falls below T1, generating risky prevalence boundaries. RAgTs in pediatric ERs/EDs parallel this pattern with asymptomatic worse than symptomatic performance. In communities, RAgTs display large uncertainty with median prevalence boundary of 14.8% for 1/20 missed diagnoses, and at prevalence > 33.3–36.9% risk 10% false omissions for symptomatic subjects. Recursive testing improves home RAgT performance. Home molecular tests elevate performance above T1 but lack adequate validation. Widespread RAgT availability encourages self-testing. Asymptomatic RAgT and PCR-based saliva testing present the highest chance of missed diagnoses. Home testing twice, once just before mingling, and molecular-based self-testing, help avoid false omissions. Community and ER/ED RAgTs can identify contagiousness in low prevalence. Real-world trials of performance, cost-effectiveness, and public health impact could identify home molecular diagnostics as an optimal diagnostic portal.
Clinical detection of low upper body blood flow in very premature infants using blood pressure, capillary refill time, and central-peripheral temperature difference
Objective: To determine the accuracy of blood pressure (BP), capillary refill time (CRT), and central-peripheral temperature difference (CPTd) for detecting low upper body blood flow in the first day after birth. Methods: A prospective, two centre cohort study of 128 infants born at < 30 weeks gestation. Invasive BP (n = 108), CRT (n = 128), and CPTd (n = 46) were performed immediately before echocardiographic measurement of superior vena cava (SVC) flow at three, 5–10, and 24 hours after birth. Results: Forty four (34%) infants had low SVC flow (< 41 ml/kg/min) in the first day, 13/122 (11%) at three hours, 39/126 (31%) at 5–10 hours, and 4/119 (3%) at 24 hours. CPTd did not detect infants with low flows. Combining all observations in the first 24 hours, CRT ⩾ 3 seconds had 55% sensitivity and 81% specificity, mean BP < 30 mm Hg had 59% sensitivity and 77% specificity, and systolic BP < 40 mm Hg had 76% sensitivity and 68% specificity for detecting low SVC flow. Combining a mean BP < 30 mm Hg and/or central CRT ⩾ 3 seconds increases the sensitivity to 78%. Conclusions: Low upper body blood flow is common in the first day after birth and strongly associated with peri/intraventricular haemorrhage. BP and CRT are imperfect bedside tests for detecting low blood flow in the first day after birth.
“Stops walking when talking” as a predictor of falls in people with stroke living in the community
Objective: To test “Stops walking when talking” (SWWT) as a predictor of falls among people with stroke living in the community. Methods: People with stroke were identified through hospital records. Mobility, ADL (activites of daily living) ability, mental state, mood, and SWWT were assessed in a single session. Participants were followed prospectively for six months, using falls diaries and regular telephone calls. Results: Sixty three participants (36 men, 27 women; mean (SD) age 68.4 (10.6)) were recruited. Four subjects had a brainstem lesion, 30 had right hemisphere, and 29 left hemisphere infarctions. Mean time since onset of stroke was 20 months (range 2–72). Twenty six subjects stopped walking when a conversation was started and 16 of them fell during the six month follow up period (11 experienced repeated falls). For all fallers (⩾1) the positive predictive value of SWWT was 62% (16/26), the negative predictive value 62% (23/37), specificity 70% (23/33) and sensitivity 53% (16/30). For repeat fallers (⩾2) the positive predictive value of SWWT was 42% (11/26), the negative predictive value 89% (33/37), specificity 69% (33/48) and sensitivity 73% (11/15). Those who stopped walking were significantly more disabled (p<0.001)—that is, they were more dependent in activities of daily living, had worse gross function as well as worse upper and lower limb function, and had depression (p = 0.012). Conclusions: The specificity of the SWWT test was lower but sensitivity was higher than previously reported. Although the SWWT test was easy to use, its clinical usefulness as a single indicator of fall risk in identifying those community dwelling people with stroke most at risk of falls and in need of therapeutic intervention is questionable.
Evaluation of “point of care” devices in the measurement of low blood glucose in neonatal practice
Background: Low blood glucose in newborns is difficult to detect clinically. Hence a reliable “point of care” device (glucometer) for early detection and treatment of low glucose is needed. Objective: To evaluate the performance of five readily available glucometers for the detection of low blood glucose in newborn infants. Method: Glucostix measurements were taken for newborns with risk factors using a Reflolux S (Boehringer) glucometer. If the initial reading was low (< 2.6 mmol/l), further measurements were taken with two other glucometers (phase I, Advantage and Glucotrend (Roche); phase II, Elite XL (Bayer) and Precision (Abbott)), and plasma glucose was measured in the laboratory (Aeroset; Abbott). Results: Over 10 months, 101 specimens were collected from 71 newborns (57 in phase I; 44 in phase II). The Advantage glucometer usually overestimated blood glucose with a mean difference of 1.07 mmol/l (p < 0.01) at all low glucose ranges. The Glucotrend, Precision, and Elite XL glucometers performed better; the mean differences were not significantly different from the laboratory measured value (0.17 mmol/l (p  =  0.37); −0.12 mmol/l (p  =  0.13), and 0.24 mmol/l (p  =  0.13) respectively). For detection of glucose concentrations < 2.6 mmol/l, the Precision glucometer had the highest sensitivity (96.4%) and negative predictive value (90%). For lower glucose concentrations (< 2.0 mmol/l), the Glucotrend glucometer performed even better (sensitivity 92.3%, negative predictive value 96.3%). Conclusion: Point of care devices should have good precision in the low glucose concentration range, sensitivity, and accuracy for early detection of neonatal hypoglycaemia. None of the five glucometers was satisfactory as the sole measuring device. The Glucotrend and Precision glucometers have the greatest sensitivity and negative predictive value. However, confirmation with laboratory measurements of plasma glucose and clinical assessment are still of the utmost importance.
Evaluation of a new transcutaneous bilirubinometer in Chinese newborns
Objective: To evaluate the use of a new transcutaneous bilirubinometer (JM-103 Minolta Airshields) for detection of hyperbilirubinaemia in term or near-term healthy Chinese newborns. Methods: Transcutaneous bilirubin (TcB) was used to screen for severe hyperbilirubinaemia in newborn infants. Blood was taken for total serum bilirubin (TSB) measurement if the initial TcB level was higher than the 40th centile in Bhutani’s nomogram. Paired TcB and TSB results were then reviewed over 6 months. The correlation as well as the mean difference between the two methods were calculated. The clinical application of TcB with Bhutani’s nomogram in the prediction of severe hyperbilirubinaemia in low-risk, medium-risk and high-risk thresholds for phototherapy was also analysed. Results: 997 paired TcB and TSB measurements were evaluated in term or near-term newborns. TcB was significantly correlated with TSB, with a correlation coefficient of 0.83 (p<0.001). Their mean difference was 21.7 μmol/l (SD 21.2, p<0.001), with the 95% limits of agreement between −19.9 and 63.3 μmol/l. In both low-risk and medium-risk thresholds for phototherapy, using the 75th centile of Bhutani’s nomogram as threshold, TcB could identify all cases and had a sensitivity and negative predictive value of 100% each, a specificity of 56% and positive predictive value of 23%. For high-risk cases, using the 75th centile as cut-off, the sensitivity and negative predictive value were reduced to 86.7% and 97.0%, respectively. Conclusion: An accurate point-of-care bilirubin analyser facilitates bilirubin screening and avoids unnecessary blood tests. Although using the transcutaneous bilirubinometer JM-103 might result in a significant difference between TcB and TSB measured in Chinese newborns, combining the use of TcB and the 75th centile in Bhutani’s nomogram as the cut-off level can identify all cases of significant hyperbilirubinaemia.
The False Positive Risk: A Proposal Concerning What to Do About p-Values
It is widely acknowledged that the biomedical literature suffers from a surfeit of false positive results. Part of the reason for this is the persistence of the myth that observation of p < 0.05 is sufficient justification to claim that you have made a discovery. It is hopeless to expect users to change their reliance on p-values unless they are offered an alternative way of judging the reliability of their conclusions. If the alternative method is to have a chance of being adopted widely, it will have to be easy to understand and to calculate. One such proposal is based on calculation of false positive risk(FPR). It is suggested that p-values and confidence intervals should continue to be given, but that they should be supplemented by a single additional number that conveys the strength of the evidence better than the p-value. This number could be the minimum FPR (that calculated on the assumption of a prior probability of 0.5, the largest value that can be assumed in the absence of hard prior data). Alternatively one could specify the prior probability that it would be necessary to believe in order to achieve an FPR of, say, 0.05.