Displaying all 14 publications

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  1. Sriraam N, Eswaran C
    J Med Syst, 2006 Dec;30(6):439-48.
    PMID: 17233156
    Two-stage lossless data compression methods involving predictors and encoders are well known. This paper discusses the application of context based error modeling techniques for neural network predictors used for the compression of EEG signals. Error modeling improves the performance of a compression algorithm by removing the statistical redundancy that exists among the error signals after the prediction stage. In this paper experiments are carried out by using human EEG signals recorded under various physiological conditions to evaluate the effect of context based error modeling in the EEG compression. It is found that the compression efficiency of the neural network based predictive techniques is significantly improved by using the error modeling schemes. It is shown that the bits per sample required for EEG compression with error modeling and entropy coding lie in the range of 2.92 to 6.62 which indicates a saving of 0.3 to 0.7 bits compared to the compression scheme without error modeling.
    Matched MeSH terms: Diagnostic Errors/prevention & control*
  2. Lewiecki EM, Binkley N, Morgan SL, Shuhart CR, Camargos BM, Carey JJ, et al.
    J Clin Densitom, 2016 Apr-Jun;19(2):127-40.
    PMID: 27020004 DOI: 10.1016/j.jocd.2016.03.003
    Dual-energy X-ray absorptiometry (DXA) is a technology that is widely used to diagnose osteoporosis, assess fracture risk, and monitor changes in bone mineral density (BMD). The clinical utility of DXA is highly dependent on the quality of the scan acquisition, analysis, and interpretation. Clinicians are best equipped to manage patients when BMD measurements are correct and interpretation follows well-established standards. Poor-quality acquisition, analysis, or interpretation of DXA data may mislead referring clinicians, resulting in unnecessary diagnostic evaluations, failure to evaluate when needed, inappropriate treatment, or failure to provide medical treatment, with potentially ineffective, harmful, or costly consequences. Misallocation of limited healthcare resources and poor treatment decisions can be minimized, and patient care optimized, through meticulous attention to DXA instrument calibration, data acquisition and analysis, interpretation, and reporting. This document from the International Society for Clinical Densitometry describes quality standards for BMD testing at DXA facilities worldwide to provide guidance for DXA supervisors, technologists, interpreters, and clinicians. High-quality DXA testing is necessary for correct diagnostic classification and optimal fracture risk assessment, and is essential for BMD monitoring.
    Matched MeSH terms: Diagnostic Errors/prevention & control*
  3. Tan HK, Bakri MM, Peh WC
    Semin Musculoskelet Radiol, 2014 Feb;18(1):45-53.
    PMID: 24515881 DOI: 10.1055/s-0034-1365834
    MR imaging is an established tool for the detection and diagnosis of various injuries and internal derangements of the knee, enabling excellent anatomical visualization and producing good soft tissue contrast and characterization. However, numerous normal variants and potential pitfalls may lead to diagnostic errors. Understanding the basic MR imaging principles, applying the correct technique, knowing the normal anatomy and variants, recognizing artifacts, and assuring good clinical and radiographic correlation helps avoid these potential pitfalls.
    Matched MeSH terms: Diagnostic Errors/prevention & control*
  4. Poh KW, Cheok LH, Liow JH, Mat Soom MA, Azlina S, Nadiah MN, et al.
    Med J Malaysia, 2020 01;75(1):7-11.
    PMID: 32008012
    OBJECTIVES: The primary objective of this study was to describe the accuracy of pneumonia diagnosis, both community-acquired pneumonia (CAP) and hospitalacquired pneumonia (HAP). Secondary objectives were describing the choice of antibiotics used, pathogens isolated, and predictive parameters in diagnosing pneumonia.

    METHODS: This was a prospective cross-sectional study to determine the accuracy of the diagnosis of CAP and HAP admitted to Hospital Tuanku Ja'afar. All patients aged ≥12 years admitted to the general medical ward with the diagnosis of CAP or HAP were included in the study. Chest radiograph interpretation was done by certified radiologists. An accurate diagnosis of pneumonia was defined by clinical signs and symptoms of pneumonia supported by radiographical evidence.

    RESULTS: A total of 159 patients were enrolled into the study from January 2018 to February 2018. Of these only 59(37.1%) cases were accurately diagnosed as pneumonia. Amongst those with pneumonia diagnosis made by the emergency department, medical officers and specialists of medical department; 65.4%, 60% and 47.3% respectively were not pneumonia. Amoxicillin with clavulanate and azithromycin were amongst the most common first choice of antibiotic used (46.5%). In this study, pathogens were isolated either by blood culture or sputum culture in only 20 (12.6%) patients. There was no significant predictive parameter identified in this study, which included white cell counts, Creactive protein (CRP) levels, erythrocyte sedimentation rate (ESR), and Pao2/FiO2 ratio.

    CONCLUSION: About two-thirds of patients diagnosed with pneumonia did not have a compatible radiological finding. Better tools and systems are needed to aid in the diagnosis of pneumonia.

    Matched MeSH terms: Diagnostic Errors/prevention & control*
  5. Mohd Norsuddin N, Mello-Thoms C, Reed W, Lewis S
    Asian Pac J Cancer Prev, 2019 Feb 26;20(2):537-543.
    PMID: 30803217
    Rationale and objectives: Target recall rates are often used as a performance indicator in mammography screening
    programs with the intention of reducing false positive decisions, over diagnosis and anxiety for participants. However,
    the relationship between target recall rates and cancer detection is unclear, especially when readers are directed to
    adhere to a predetermined rate. The purpose of this study was to explore the effect of setting different recall rates on
    radiologist’s performance. Materials and Methods: Institutional ethics approval was granted and informed consent
    was obtained from each participating radiologist. Five experienced breast imaging radiologists read a single test set
    of 200 mammographic cases (20 abnormal and 180 normal). The radiologists were asked to identify each case that
    they required to be recalled in three different recall conditions; free recall, 15% and 10% and mark the location of any
    suspicious lesions. Results: Wide variability in recall rates was observed when reading at free recall, ranging from
    18.5% to 34.0%. Readers demonstrated significantly reduced performance when reading at prescribed recall rates,
    with lower sensitivity (H=12.891, P=0.002), case location sensitivity (H=12.512, P=0.002) and ROC AUC (H=11.601,
    P=0.003) albeit with an increased specificity (H=12.704, P=0.002). However, no significant changes were evident in
    lesion location sensitivity (H=1.982, P=0.371) and JAFROC FOM (H=1.820, P=0.403). Conclusion: In this laboratory
    study, reducing the number of recalled cases to 10% significantly reduced radiologists’ performance with lower detection
    sensitivity, although a significant improvement in specificity was observed.
    Matched MeSH terms: Diagnostic Errors/prevention & control*
  6. Chew KS, van Merrienboer JJG, Durning SJ
    BMC Med Educ, 2017 Nov 29;17(1):234.
    PMID: 29187172 DOI: 10.1186/s12909-017-1078-x
    BACKGROUND: A key challenge clinicians face when considering differential diagnoses is whether the patient data have been adequately collected. Insufficient data may inadvertently lead to premature closure of the diagnostic process. This study aimed to test the hypothesis that the application of a mnemonic checklist helps to stimulate more patient data collection, thus leading to better diagnostic consideration.

    METHODS: A total of 88 final year medical students were assigned to either an educational intervention group or a control group in a non-equivalent group post-test only design. Participants in the intervention group received a tutorial on the use of a mnemonic checklist aimed to minimize cognitive errors in clinical decision-making. Two weeks later, the participants in both groups were given a script concordance test consisting of 10 cases, with 3 items per case, to assess their clinical decisions when additional data are given in the case scenarios.

    RESULTS: The Mann-Whitney U-test performed on the total scores from both groups showed no statistical significance (U = 792, z = -1.408, p = 0.159). When comparisons were made for the first half and the second half of the SCT, it was found that participants in the intervention group performed significantly better than participants in the control group in the first half of the test, with median scores of 9.15 (IQR 8.00-10.28) vs. 8.18 (IQR 7.16-9.24) respectively, U = 642.5, z = -2.661, p = 0.008. No significant difference was found in the second half of the test, with the median score of 9.58 (IQR 8.90-10.56) vs. 9.81 (IQR 8.83-11.12) for the intervention group and control group respectively (U = 897.5, z = -0.524, p = 0.60).

    CONCLUSION: Checklist use in differential diagnoses consideration did show some benefit. However, this benefit seems to have been traded off by the time and effort in using it. More research is needed to determine whether this benefit could be translated into clinical practice after repetitive use.

    Matched MeSH terms: Diagnostic Errors/prevention & control*
  7. Yew YC, Nurul-Fatin FS, Norazita AT
    Med J Malaysia, 2017 12;72(6):376-377.
    PMID: 29308780 MyJurnal
    Panuveitis secondary to masquerade syndrome is uncommon. A middle-aged woman presented to the ophthalmology clinic with panuveitis associated with anaemia, joint pain, and renal impairment. An incidental finding of a lytic lesion over her left scapula following a chest x-ray prompted further skeletal survey and revealed further lytic lesions over the skull and pelvic bone. Bone marrow aspiration was performed and this confirmed the diagnosis of multiple myeloma. Her left eye vision and intraocular inflammation improved after commencement of chemotherapy. A detailed history is important to elucidate the aetiology of masquerade syndrome and to prevent any delayed diagnosis of underlying malignancy.
    Matched MeSH terms: Diagnostic Errors/prevention & control
  8. Choy YS, Bhattacharya K, Balasubramaniam S, Fietz M, Fu A, Inwood A, et al.
    Mol Genet Metab, 2015 May;115(1):41-7.
    PMID: 25892708 DOI: 10.1016/j.ymgme.2015.03.005
    Mucopolysaccharidosis VI (MPS VI, Maroteaux-Lamy syndrome) is caused by deficient activity of the enzyme, N-acetylgalactosamine-4-sulfatase, resulting in impaired degradation of the glycosaminoglycan dermatan sulfate. Patients experience a range of manifestations including joint contractures, short stature, dysostosis multiplex, coarse facial features, decreased pulmonary function, cardiac abnormalities, corneal clouding and shortened life span. Recently, clinicians from institutions in the Asia-Pacific region met to discuss the occurrence and implications of delayed diagnosis and misdiagnosis of MPS VI in the patients they have managed. Eighteen patients (44% female) were diagnosed. The most common sign presented by the patients was bone deformities in 11 patients (65%). Delays to diagnosis occurred due to the lack of or distance to diagnostic facilities for four patients (31%), alternative diagnoses for two patients (15%), and misleading symptoms experienced by two patients (15%). Several patients experienced manifestations that were subtler than would be expected and were subsequently overlooked. Several cases highlighted the unique challenges associated with diagnosing MPS VI from the perspective of different specialties and provide insights into how these patients initially present, which may help to elucidate strategies to improve the diagnosis of MPS VI.
    Matched MeSH terms: Diagnostic Errors/prevention & control
  9. Ousey K, Chadwick P, Jawien A, Tariq G, Nair HKR, Lázaro-Martínez JL, et al.
    J Wound Care, 2018 05 01;27(Sup5):S1-S52.
    PMID: 29738280 DOI: 10.12968/jowc.2018.27.Sup5.S1
    Matched MeSH terms: Diagnostic Errors/prevention & control
  10. Gan CY, Zainuddin Z, Muhamad Noh H, Rahmat R, Mohd Akir F, Mahad NH, et al.
    Forensic Sci Int, 2019 Sep;302:109865.
    PMID: 31279278 DOI: 10.1016/j.forsciint.2019.06.023
    Consumption of curry containing poppy seeds has raised an issue concerning the opiate content in the urine that might exceed the cut-off value (300ng/mL). The main objective of this study was to examine the morphine and codeine contents in the urine of the consumers after partaking poppy seed-enriched curry in. The volunteers were asked to partake: (a) a single meal and their urines were collected within 24h, or (b) Two meals a day for three consecutive days and their urines were collected within 72h. Two different dosages were also tested in this study: (a) low dosage: 1g/100ml curry (containing 138μg of morphine and 66μg of codeine) and (b) high dosage: 5g/100ml curry (containing 690μg of morphine and 330μg of codeine). The subjects were randomised into the groups using the method of stratified randomization with age and gender groups as covariates. A total of 6 subjects was allocated for each group and placebos were used as control. Results showed that all subjects who consumed low dosage of poppy seeds either in single meal or multiple meals experiment were found negative. However, 1 out of 6high dosage subjects was confirmed positive at a period of 3-6h after the consumption of curry in the single meal study. This outlier maybe due to the lack of water consumption after consuming the curry, thus the low volume of urine was collected and the opiate was concentrated in the urine. On the other hand, 5 out of 6high dosage subjects in the multiple meals experiment were found positive. Majority of these subjects were found positive on the second and third day of the experiment after the second curry meal was consumed. The outlier (negative) in this group might be due to the high consumption of water throughout the experiment and the subject's urine volumes and frequency of urine collection were much higher compared to other subjects. From the result of this study, it can be concluded that partaking high dosages of poppy seed in curry could give a positive response (>300ng/ml+uncertainty of measurement) in the urine, and the water consumption after partaking curry has significant influence for the opiate contents in the urine.
    Matched MeSH terms: Diagnostic Errors/prevention & control
  11. Gupta ED, Sakthiswary R
    Asian Cardiovasc Thorac Ann, 2014 May;22(4):397-401.
    PMID: 24771726 DOI: 10.1177/0218492313484917
    The objectives of this study were to determine the incidence of a myocardial infarction "false alarm" and evaluate the efficacy of the initial electrocardiogram and cardiac enzymes in diagnosing myocardial infarction in Malaysia.
    Matched MeSH terms: Diagnostic Errors/prevention & control
  12. Amir A, Cheong FW, De Silva JR, Lau YL
    Parasit Vectors, 2018 01 23;11(1):53.
    PMID: 29361963 DOI: 10.1186/s13071-018-2617-y
    Every year, millions of people are burdened with malaria. An estimated 429,000 casualties were reported in 2015, with the majority made up of children under five years old. Early and accurate diagnosis of malaria is of paramount importance to ensure appropriate administration of treatment. This minimizes the risk of parasite resistance development, reduces drug wastage and unnecessary adverse reaction to antimalarial drugs. Malaria diagnostic tools have expanded beyond the conventional microscopic examination of Giemsa-stained blood films. Contemporary and innovative techniques have emerged, mainly the rapid diagnostic tests (RDT) and other molecular diagnostic methods such as PCR, qPCR and loop-mediated isothermal amplification (LAMP). Even microscopic diagnosis has gone through a paradigm shift with the development of new techniques such as the quantitative buffy coat (QBC) method and the Partec rapid malaria test. This review explores the different diagnostic tools available for childhood malaria, each with their characteristic strengths and limitations. These tools play an important role in making an accurate malaria diagnosis to ensure that the use of anti-malaria are rationalized and that presumptive diagnosis would only be a thing of the past.
    Matched MeSH terms: Diagnostic Errors/prevention & control
  13. Phang ZH, Miskon MFB, Ibrahim SB
    J Med Case Rep, 2018 Jul 18;12(1):211.
    PMID: 30016981 DOI: 10.1186/s13256-018-1751-7
    BACKGROUND: Blunt trauma causing brachial artery injury in a young patient is very rare. Cases of brachial artery injury may be associated with closed elbow dislocation or instability. Elbow dislocation may not be evident clinically and radiologically on initial presentation.

    CASE PRESENTATION: This is a case of a 37-year-old, right-hand dominant, Malay man who fell approximately 6 meters from a rambutan tree and his left arm hit the tree trunk on his way down. He was an active tobacco smoker with a 20 pack year smoking history. On clinical examination, Doppler signals over his radial and ulnar arteries were poor. He proceeded with emergency computed tomography angiogram of his left upper limb which showed non-opacification of contrast at the distal left brachial artery just before the bifurcation of the left brachial artery at his left elbow joint. Radiographs and computed tomography scan also showed undisplaced fracture of left lateral epicondyle and radial head with no evidence of elbow dislocation. He subsequently underwent left brachial to brachial artery bypass which was done using reversed saphenous vein graft and recovered well. His fractures were treated using 90 degree long posterior splint for 2 weeks and he was then allowed early range of motion of the left elbow. This patient developed left elbow dislocation 6 weeks postoperatively. Closed manipulative reduction of his left elbow resulted in incomplete reduction. The functional outcome of his left elbow was limited with a range of motion of left elbow of 0-45 degrees. However, he was not keen for surgery to stabilize his elbow joint during his last follow-up 6 months post injury.

    CONCLUSIONS: This is an uncommon case of brachial artery injury in a civilian caused by blunt trauma associated with occult elbow instability/dislocation and minor fractures around the elbow joint. The treatment of brachial artery injury with clinical evidence of distal ischemia is surgical revascularization. The possibility of elbow instability and dislocation need to be considered in all cases of brachial artery injury because early radiographs and computed tomography scans may be normal. Short-term posterior splint immobilization is not sufficient to prevent recurrent dislocations.

    Matched MeSH terms: Diagnostic Errors/prevention & control
  14. Samsudin EZ, Kamarul T, Mansor A
    Singapore Med J, 2015 May;56(5):e92-5.
    PMID: 26034328 DOI: 10.11622/smedj.2015082
    Any medical diagnosis should take a multimodal approach, especially those involving tumour-like conditions, as entities that mimic neoplasms have overlapping features and may present detrimental outcomes if they are underdiagnosed. These case reports present diagnostic pitfalls resulting from overdependence on a single diagnostic parameter for three musculoskeletal neoplasm mimics: brown tumour (BT) that was mistaken for giant cell tumour (GCT), methicillin-resistant Staphylococcus aureus osteomyelitis mistaken for osteosarcoma and a pseudoaneurysm mistaken for a soft tissue sarcoma. Literature reviews revealed five reports of BT simulating GCT, four reports of osteomyelitis mimicking osteosarcoma and five reports of a pseudoaneurysm imitating a soft tissue sarcoma. Our findings highlight the therapeutic dilemmas that arise with musculoskeletal mimics, as well as the importance of thorough investigation to distinguish mimickers from true neoplasms.
    Matched MeSH terms: Diagnostic Errors/prevention & control
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