The aim of the study was to validate the Malay version of the General Quentionnaire (GHQ-12) in patients with psychiatric morbidity secondary to urological disorder. Validity and reliability were studied in patients with lower urinary tract symptoms (LUTS) and patients without LUTS. Internal consistency was excellent. A high degree of internal consistency was observed for each of the 12 items and total scores (Cronbach's alpha value = 0.50 and higher and 0.65 respectively. Test-retest correlation coefficient for the 12 items scores was highly significant. Intraclass correlation coefficient was high (ICC=0.47 and above). A significant level between baseline and post-treatment scores were observed across 3 items in the surgical group. The Mal-GHQ-12 is a suitable, reliable, valid and sensitive to clinical change in the Malaysian population.
To evaluate the performance of contrastenhanced ultrasound (CEUS) in the risk stratification of indeterminate renal lesions picked up incidentally on abdominal imaging, in patients with renal impairment.
Currently, it is almost impossible to diagnose a patient at the onset of
sepsis due to the lack of real-time metrics with high sensitivity and specificity. The
purpose of the present study is to determine the diagnostic value of model-based insulin
sensitivity (SI) as a new sepsis biomarker in critically ill patients, and compare its
performance to classical inflammatory parameters. (Copied from article).
This study demonstrates that the clinical sensitivity, specificity and reproducibility of the novel cobas HPV test on the cobas 6800 system for high-risk HPV types fulfils the criteria for use in population based cervical screening. The criteria were formulated by an international consortium, using the cobas 4800 HPV test as a validated reference assay. The cobas HPV test detected over 98% of histologically confirmed CIN2+ lesions in woman aged 30 years or older with a specificity of 98.9% when compared with the reference cobas 4800 test. Both the intra- and inter-laboratory agreement for the cobas HPV test were 98%. The clinical performance of the cobas HPV test is comparable to longitudinally validated HPV assays and fulfils the criteria for use in primary cervical screening.
OBJECTIVE: The aim of this study was to compare the use of semi-automated (Medax Velox 2; Poggio Rusco, Italy) and automated (Bard Magnum Biopsy Instrument; Covington, GA, USA) core biopsy needles, for ultrasound guided breast biopsy.
MATERIALS AND METHODS: A 14G semi-automatic spring loaded core biopsy needle with a 22-mm-throw (Medax Velox 2; Poggio Rusco, Italy) and 14-gauge automated needle device with a 22-mm-throw biopsy gun (Bard-Magnum Biopsy Instrument, Covington, GA, USA) were used for breast biopsies under ultrasound guidance on alternate months during the study period between July 2009 and May 2011. One hundred and sixty lesions were biopsied and specimens were sent for histological evaluation.
RESULTS: The automated needle obtained a higher number of histology reports at 84% (67/80) as compared with the semiautomated needle at 60% (48/80) (Fisher exact test, p value=0.023). Inadequate samples with the automated needle were much less at 9% (7/60) than with the semiautomated needle at 23% (18/60) (Fisher exact test, p value=0.028). The semi-automated needle showed slightly less fragmented samples. However, the number of fragmented samples with definitive diagnosis was slightly higher with the automated compared with the semiautomated needle, at 16% (13/80) and 13% (10/80) respectively. Compared with histology of 29 lesions that were excised, the semi-automated needle had higher sensitivity (100%) but lower specificity (75%) and accuracy (90%) compared with the automated needle (88% sensitivity, 100% specificity, 95% accuracy).
CONCLUSION: Definitive diagnosis from the study samples slightly favours the use of automated core biopsy needle as compared to semi-automated core biopsy needle.
Study site: Universiti Kebangsaan Malaysia Medical Centre, Kuala Lumpur
Thyroid nodules are common but thyroid malignancies are not. Fine needle aspiration (FNA) cytology is a diagnostic tool used to screen patients with thyroid nodules who require surgery. We study the diagnostic accuracy of FNA as the initial diagnostic modality in the clinical assessment of thyroid nodules. Between January 1995 until December 2000, 2131 FNA of thyroid nodules were performed. Four hundred and forty-one (20.7%) of these were unsatisfactory and 1690 (79.3%) cases were satisfactory for cytological evaluation. Histopathological diagnosis were available for 361 cases. Cyto-histopathological correlation was carried out for these cases. Our results showed a diagnostic accuracy of 96.2% with sensitivity and specificity rates of 87.7% and 98.4% res- pectively. Our positive predictive value is 93.4% and our negative predictive value is 96.8%. From this study, we conclude that fine needle aspiration is an important initial screening diagnostic tool for the investigation of thyroid nodules.
This study aimed to validate the Malay Version of Copenhagen Psychosocial Questionnaire for Malaysian use and application for assessing psychosocial work environment factors. Validity and Reliability were studied in 50 staff nurses of Hospital Selayang. The validity of the questionnaire was evaluated by calculating the percentage of sensitivity and specificity at the different score level. Both percentage of sensitivity against specificity were plotted to produce a ROC (Receiver Operating Characteristics) curve, and score 52 has the highest both sensitivity and specificity was used as an overall index that expresses the probability that measure the psychosocial problems. For reliability purposes, a descriptive of Test-Retest Mean Scores and Paired Sample T-Test and the coefficient-correlation test were calculated. The Test-Retest Mean Scores and Paired Sample T-Test for all 26 scales were calculated and showed statistically not significant. The reliability of the questionnaire and its 26 scales was assessed by using Pearson (r) (overall questionnaire r within a range of 0.00 to 1.00). The COPSOQ appears to be a reliable and responsive measure of workers for Malaysian use and can be applied for assessing psychosocial work environment factors.
Strongyloidiasis is a major neglected tropical disease with the potential of causing lifelong infection and mortality. One of the ways for effective control of this disease is developing improved diagnostics, particularly using serological approaches. A serological test can achieve high diagnostic sensitivity and specificity, has the potential for point-of-care translation, and can be used as a screening tool for early detection. More research is needed to find clinically important antibody biomarkers for early disease detection, mapping, and epidemiological surveillance. This article summarizes human strongyloidiasis and the available diagnostic tools for the disease, focusing on describing the current antibody assays for strongyloidiasis. Finally, prospects of developing a more effective serodiagnostic tool for strongyloidiasis are discussed.
Software optical mark recognition (SOMR) is the process whereby information entered on a survey form or questionnaire is converted using specialized software into a machine-readable format. SOMR normally requires input fields to be completely darkened, have no internal labels, or be filled with a soft pencil, otherwise mark detection will be inaccurate. Forms can also have print and scan artefacts that further increase the error rate. This article presents a new method of mark detection that improves over existing techniques based on pixel counting and simple thresholding. Its main advantage is that it can be used under a variety of conditions and yet maintain a high level of accuracy that is sufficient for scientific applications. Field testing shows no software misclassification in 5695 samples filled by trained personnel, and only two misclassifications in 6000 samples filled by untrained respondents. Sensitivity, specificity, and accuracy were 99.73%, 99.98%, and 99.94% respectively, even in the presence of print and scan artefacts, which was superior to other methods tested. A separate direct comparison for mark detection showed a sensitivity, specificity, and accuracy respectively of 99.7%, 100.0%, 100.0% (new method), 96.3%, 96.0%, 96.1% (pixel counting), and 99.9%, 99.8%, 99.8% (simple thresholding) on clean forms, and 100.0%, 99.1%, 99.3% (new method), 98.4%, 95.6%, 96.2% (pixel counting), 100.0%, 38.3%, 51.4% (simple thresholding) on forms with print artefacts. This method is designed for bubble and box fields, while other types such as handwriting fields require separate error control measures.
The choice of an electroencephalogram (EEG) reference has fundamental importance and could be critical during clinical decision-making because an impure EEG reference could falsify the clinical measurements and subsequent inferences. In this research, the suitability of three EEG references was compared while classifying depressed and healthy brains using a machine-learning (ML)-based validation method. In this research, the EEG data of 30 unipolar depressed subjects and 30 age-matched healthy controls were recorded. The EEG data were analyzed in three different EEG references, the link-ear reference (LE), average reference (AR), and reference electrode standardization technique (REST). The EEG-based functional connectivity (FC) was computed. Also, the graph-based measures, such as the distances between nodes, minimum spanning tree, and maximum flow between the nodes for each channel pair, were calculated. An ML scheme provided a mechanism to compare the performances of the extracted features that involved a general framework such as the feature extraction (graph-based theoretic measures), feature selection, classification, and validation. For comparison purposes, the performance metrics such as the classification accuracies, sensitivities, specificities, and F scores were computed. When comparing the three references, the diagnostic accuracy showed better performances during the REST, while the LE and AR showed less discrimination between the two groups. Based on the results, it can be concluded that the choice of appropriate reference is critical during the clinical scenario. The REST reference is recommended for future applications of EEG-based diagnosis of mental illnesses.
A shelf-stable loop-mediated isothermal amplification (LAMP) reagent for Burkholderia pseudomallei detection is described. The coupling of LAMP reagents with the indirect colorimetric indicator and consequently its lyophilization enable the simple evaluation of results without the need for any advance laboratory instruments. The reagents were found to have a stable shelf life of at least 30 days with well-maintained sensitivity and specificity.
AIM: To determine the (i) sensitivity and specificity of ultrasound (USG) in the detection of urinary tract calculi, (ii) size of renal calculi detected on USG, and (iii) size of renal calculi not seen on USG but detected on computed tomography urogram (CTU).
METHODS: A total of 201 patients' USG and CTU were compared retrospectively for the presence of calculi. Sensitivity, specificity, accuracy, positive predictive value and negative predictive value of USG were calculated with CTU as the gold standard.
RESULTS: From the 201 sets of data collected, 59 calculi were detected on both USG and CTU. The sensitivity and specificity of renal calculi detection on USG were 53% and 85% respectively. The mean size of the renal calculus detected on USG was 7.6 mm ± 4.1 mm and the mean size of the renal calculus not visualised on USG but detected on CTU was 4 mm ± 2.4 mm. The sensitivity and specificity of ureteric calculi detection on USG were 12% and 97% respectively. The sensitivity and specificity of urinary bladder calculi detection on USG were 20% and 100% respectively.
CONCLUSION: This study showed that the accuracy of US in detecting renal, ureteric and urinary bladder calculi were 67%, 80% and 98% respectively.
Study site: Universiti Kebangsaan Malaysia Medical Centre, Kuala Lumpur
MicroRNAs regulate gene expression at the post-transcriptional level. Differential expression of miRNAs can potentially be used as biomarkers for early diagnosis and prediction for outcomes. Failure in validation of miRNA profiles is often caused by variations in experimental parameters. In this study, the performance of five extraction kits and three RT-qPCR systems were evaluated using BioMark high-throughput platform and the effects of different experimental parameters on circulating miRNA levels were determined. Differences in the performance of extraction kits as well as varying accuracy, sensitivity and reproducibility in qPCR systems were observed. Normalisation of RT-qPCR data to spike-in controls can reduce extraction bias. However, the extent of correlation for different qPCR systems varies in different assays. At different time points, there was no significant fold change in eight of the plasma miRNAs that we evaluated. Higher level of miRNAs was detected in plasma as compared to serum of the same cohort. In summary, we demonstrated that high-throughput RT-qPCR with pre-amplification step had increased sensitivity and can be achieved with accuracy and high reproducibility through stringent experimental controls. The information provided here is useful for planning biomarker validation studies involving circulating miRNAs.
BACKGROUND: to determine the usefulness of Doppler ultrasound measurement of resistive index (RI) in differentiating obstructive from non-obstructive hydronephrosis in children.
METHODS: From August 2011 to November 2012, renal Doppler assessments of the intra-renal renal arteries were performed on 16 children (19 kidneys) with congenital hydronephrosis. the independent t-test was used to assess for significant difference in RI values between those with obstructive hydronephrosis (6 kidneys) and those with non-obstructive hydronephrosis (13 kidneys) as determined by dynamic renal scintigraphy. the assessor was blinded to the clinical findings and scintigraphy results.
RESULTS: RI was significantly different between obstructive and non-obstructive hydronephrosis. Obstructive hydronephrosis returned higher RI values, with mean RI of 0.78. Mean RI in non-obstructive hydronephrosis was 0.70, and the difference was significant (p <0.05). the sensitivity and specificity of Doppler ultrasound were 100% and 53% respectively.
CONCLUSION: Doppler ultrasound measurement of resistive index is useful in differentiating obstructive from nonobstructive hydronephrosis and provides an alternative non-ionizing investigation.
Study site: Universiti Kebangsaan Malaysia
Medical Centre, Kuala Lumpur, Malaysia
This short-term study which was carried out in a small group of pre- and postmenopausal women at Hospital Raja Perempuan Zainab II (HRPZII) aims to compare between Tscores detected by heel Quantitative Ultrasound (QUS) and by Dual X-ray Absorptiometry (DXA) of the hip and spine. The prevalence of osteoporosis by heel QUS was 63.3% and up to 16.7% by DXA. Insufficient or weak agreement exists between T-score measurements by heel QUS and axial DXA. Significant correlations were found between measurements of T-scores by both methods, with r values from 0.364 to 0.91. Although some correlation was found, significant discrepancy in the frequency of osteoporosis using different methods and sites is substantial.
Rural health clinics in Sri Aman Division in Sarawak, Malaysia lack diagnostic tests for malaria. Many of the medical assistants in the clinic diagnose malaria solely on clinical ground. The study was to determine the sensitivity, specificity and positive predictive value of clinical diagnosis of rnahtria made by medical assistants using results of microscopy examination as gold standard. The study period was from September to December 2003. Three rural clinics without laboratory or diagnostic tests services and one urban clinic with laboratory facility serving malarious areas were selected. All patients clinically diagnosed as malaria by the attending medical assistants were included as clinical malaria cases. Blood slides were taken for examination of malaria parasites. Non clinical malaria cases were all other patients without clinical malaria for whom blood slides were taken for malaria parasites. Out of 362 patients included in the study, 75 were clinically diagnosed as having mahria. The sensitivity of headache, history of fever and chills/rigors to detect malaria cases was above 90% but the specificity and positive predictive value was low, below 40% and 20% respectively. The sensitivity, specificity and positive predictive value of malaria clinical diagnosis made by medical assistants was 82.1 %, 84 .4% and 30.7% respectively. Clinical diagnosis of malaria increases the slide positive rate by four folds. However the sensitivity, specincity and positive predictive value of clinical diagnosis by medical assistant and clinical characteristics was insufficient to enable each of them to be used alone to differentiate true malaria cases from non mahiria cases.
The aim of the study was to research the use of a simple neural network in diagnosing angina in patients complaining of chest pain. A total of 887 records were extracted from the electronic medical record system (EMR) in Selayang Hospital, Malaysia. Simple neural networks (simple perceptrons) were built and trained using a subset of 470 records with and without pre-processing using principal components analysis (PCA). These were subsequently tested on another subset of 417 records. Average sensitivity of 80.75% (95% CI 79.54%, 81.96%), specificity of 41.64% (95% CI 40.13%, 43.15%), PPV of 46.73% (95% CI 45.20%, 48.26%) and NPV of 77.39% (95% CI 76.11%, 78.67%) were achieved with the simple perceptron. When PCA pre-processing was used, the perceptrons had a sensitivity of 1.43% (95% CI 1.06%, 1.80%), specificity of 98.32% (95% CI 97.92%, 98.72%), PPV of 32.95% (95% CI 31.51%, 34.39%) and NPV of 61.33% (95% CI 59.84%, 62.82%). These results show that it is possible for a simple neural network to have respectable sensitivity and specificity levels for angina.
The source of gastrointestinal bleeding (GIB) remains uncertain in patients presenting without hematemesis. This paper aims at studying the accuracy, specificity and sensitivity of the Naive Bayesian Classifier (NBC) in identifying the source of GIB in the absence of hematemesis. Data of 325 patients admitted via the emergency department (ED) for GIB without hematemesis and who underwent confirmatory testing were analysed. Six attributes related to demography and their presenting signs were chosen. NBC was used to calculate the conditional probability of an individual being assigned to Upper Gastrointestinal bleeding (UGIB) or Lower Gastrointestinal bleeding (LGIB). High classification accuracy (87.3 %), specificity (0.85) and sensitivity (0.88) were achieved. NBC is a useful tool to support the identification of the source of gastrointestinal bleeding in patients without hematemesis.
Background: The General Health Questionnaire is a widely used scale to measure psychological distress. This scale is available in many languages. The original version comprised of 60 items. It is available in 30-items, 28- items, 20-items and 12-items. The shorter version is as good as the longer version of the scale. Objective: The aim of this investigation was to determine the sensitivity, specificity and reliability of the 12-item. General Health Questionnaire (GHQ-12) among university students. Method: A total of 280 undergraduate students were selected using convenient sampling. Result: The results of this study showed that the GHQ-12 is multidimensional and contains three factor structures. It has a high internal consistency and a useful instrument to measure the psychological wellbeing of university students in Malaysia Previous authors have suggested that the cut-off point is determined by the mean. Findings from this study, based on sensitivity and specificity, suggests that mean may not be a good option. This study recommends the best cut-off point is determined by the ROC. Conclusion: This study shows that the GHQ-12 is a valid and reliable instrument to detect psychological distress among university students. The optimum cut-off point
of the GHQ-12 score to detect psychological distress was 15/16.
A 21-year old medical student consults the doctor for a fever that started 3 days ago. The fever was high grade and associated with generalised body aches. There was no gum bleeding. He mentioned that mosquito fogging was conducted in his neighbourhood recently.Physical examination revealed an alert conscious young man. Temperature (oral): 38.9 ͦ C, blood pressure 100/70 mmHg, pulse rate 90/min, good volume. Mild flushing was noted. No petechiae were seen in his legs. Tourniquet test was positive.