INTRODUCTION: Patients with asthma-like symptoms pose a diagnostic dilemma when physical examination is normal. The usual practice in Malaysia would be to give empirical asthma treatment. Bronchial challenge test (BCT) is widely used in many countries to diagnose asthma objectively but it is not widely available in Malaysia.
OBJECTIVE: To describe our experience with BCT using methacholine at Queen Elizabeth Hospital as a supporting tool in the investigation of patients with asthma-like symptoms.
METHODOLOGY: Review of case notes of patients who underwent BCT from July 2008 till April 2009. BCT was performed via dosimeter technique. Results were classified as high hyper responsiveness if the provocative dose of methacholine required to achieve 20% fall in FEV1 (PD20) was less than or equal to 0.125 micromol, moderate hyper responsiveness if PD20 was between 0.125 to 1.99 micromol or mild hyper responsiveness if PD20 was between 2.00 to 6.6 micromol. PD20 of more than 6.6 micromol constitutes a negative MCT.
RESULTS: 29 patients had BCT during the study period. 19 cases were included in this review. The age ranged from 13 to 70 years old. There were 12 males and 7 females. Duration of symptoms ranged from 2 weeks to 23 years. BCT was positive (mild or moderate hyper responsiveness) in 10 out of 19 patients. No patient had high bronchial hyper responsiveness.
CONCLUSIONS: BCT is a useful adjunctive tool in the investigation of patients presenting with asthma-like symptoms. This test obviates empirical asthma treatment. BCT should be made available in all major hospitals in Malaysia.
In this study, we sought to determine whether laboratory and physiological parameters can be useful in predicting mortality in patients with sepsis-induced hypotension and septic shock.
HLA-DQA1, -DQB1, and -DRB1 gene polymorphism were analyzed to study type 1 DM susceptibility in Malay patients from Southeast Asia (Malaysia and Singapore). Patients showed significant increases in the occurrence of DQA1*0501 (50.7% vs. 20.4%; RR = 3.97; Pc < 0.01), DQB1*0201 (48% vs. 19.1%; RR = 3.86; Pc < 0.05), and DRB1*0301 (38.7 vs. 6.8%; RR = 8.36; 95% Pc < 0.05). Conversely, significant decreases were noted in the occurrence of DQA1*0601 (14.7% vs. 35.2%; RR = 0.33; Pc = 0.008) and DQB1*0601 (4% vs. 23.5%; RR = 0.16; Pc < 0.05) in type 1 DM patients. Using a logistic regression model, we derived a risk prediction model for type 1 DM in our indigenous Malay population based on the identified HLA genotypes. The RR for type 1 DM increases by a factor of 5.68 for every unit increase in the number of DRB1*0301 allele (P < 0.001), and decreases by a factor of 0.18 per unit increase in the number of DQB1*0601 allele (P < 0.001). After adjusting for these two HLA genotypes, DQA1*0501, DQB1*0201 and DQA1*0601 were not statistically significant as risk predictors. The lower incidence of type 1 DM in the Malay population may be contributed by the genotypic combinations of DR and DQ genes as well as the linkage disequilibria between susceptible and protective alleles.
Thrombolysis in Myocardial Infarction (TIMI) score has been used to predict outcomes in patients presenting with unstable angina (UA) and non-ST elevation myocardial infarction (NSTEMI). Our study assessed other clinical predictors for patients with UA/NSTEMI undergoing early percutaneous coronary intervention (PCI).
We compared a newer serum specific IgE (SSIgE) test with skin prick testing (SPT) in the diagnosis of allergy in Malaysia. Ninety newly diagnosed allergic patients were enrolled for both tests. Using SPT as a clinical gold standard, the sensitivity, specificity, positive, and negative predictive values (PPV, NPV) were calculated for SSIgE for each of the common allergens tested. The highest positive results for both SPT and SSIgE were for house dust mite and cat. Compared to SPT, SSIgE showed better sensitivity but poorer specificity, low PPV and good NPV in all the allergens tested. Significant positive correlation was seen between the diameter of wheal and flare of SPT and the SSIgE results.
We evaluated the performance of four rapid influenza diagnostic test methods (RIDT) compared to real-time reverse-transcription polymerase chain reaction (rRT-PCR), for the detection of the novel swine-origin influenza A (H1N1) virus (S-OIV) in August 2009. A total of 270 respiratory specimens were tested with rRT-PCR, where 74 of these were tested by BinaxNow (Inverness), 80 by QuickVue (Quidel), 37 by Influenza A Antigen Rapid Test (Rockeby Biomed) and 79 by Directigen (BD). The sensitivities ranged from 4.4% to 37.0%, specificities 90.9% to 100.0%, positive predictive values 75.0% to 100.0% and negative predictive values 32.3% to 75.0%. RIDT were able to detect S-OIV but the sensitivities were low. The limitations of RIDT must be considered when interpreting results for clinical management.
Varicella-zoster virus (VZV) infections are a particular problem in healthcare settings. A survey of chickenpox was carried out amongst healthcare workers (HCWs) following potential ward exposures. A prior history of chickenpox was given by 61/98 (62.2%). Of 64 HCWs tested for VZV IgG, 10 (15.6%) were seronegative, indicating susceptibility. The sensitivity, specificity, positive predictive value, and negative predictive value of a history of prior chickenpox were 57.4%, 90%, 96.4%, and 31.0%, respectively. VZV screening of HCWs without a history of chickenpox, and vaccination of susceptible HCWs should be undertaken in this hospital.
In order to investigate the reliability of detecting HPV DNA in cervical smears, we compared the performance of nested MY/GP PCR and FDA approved-Hybrid Capture II (HCII) using clinical cervical scrapings from 40 patients. It was found that PCR was more sensitive (81.8%) in comparison to HCII (36.4%) in detecting HPV although specificity of HCII was much higher (96.6%) than PCR (58.6%). The Negative Predictive Value (NPV) of both the techniques were quite similar but Positive Predictive Value (PPV) of HCII was much higher (80.0%) compared to PCR (42.9%). While the HCII method showed good specificity for HPV detection, its lack of sensitivity as compared to PCR may be a drawback for diagnostic use.
We tried to understand whether there are significant cut off values simply determining body mass index (BMI). The study was performed in Internal Medicine Polyclinics on consecutive check up patients aged between 15 and 70 years to see possible consequences of excess weight on health and to avoid debility induced weight loss in elders. Insulin using diabetics and patients with devastating illnesses were excluded to avoid their possible effects on weight. Cases were subdivided into three groups according to their body weights as under 65, between 65 and 85, and above 85 kg groups and prevalences of underweight, normal weight, overweight, and obesity were determined. Sensitivity, specificity, and positive and negative predictive values of body weights to determine BMI were calculated. The study included 954 cases (566 females). Sensitivity of 65 kg as a cut off value to detect normal weight was 61.0%, specificity 94.3%, positive predictive value 82.9%, and negative predictive value was 97.6%. Similarly, sensitivity, specificity, and positive and negative predictive values of 65 and 85 kg to detect overweight cases were 71.5%, 63.3%, 56.2%, and 77.1% respectively. So both values were statistically significant to detect normal weight, overweight and obese individuals (p = 0.000 for both). Although BMI is probably a more valuable parameter to show weight status, the cut off values of 65 and 85 kg, as an easier way, have significant places, too.
Thrombocytopaenia is often relied upon as an important criterion for the diagnosis of dengue infection among patients presenting with an acute non-specific febrile illness. This study was aimed to assess usefulness of thrombocytopaenia in the diagnosis of acute dengue virus infection. This was a clinic based prospective cohort study from May to November 2003. Consecutive patients presenting with acute non-specific febrile illness of less than two weeks were selected from two urban primary care centres. We did full blood count examination (FBC) on the day of visit and dengue serology on day five of illness for all patients enrolled. We repeated the FBC examination for patients who had initial normal platelet counts. Thrombocytopaenia was defined as platelet count < 150 X 10(9)/L. Eighty-seven patients enrolled in the study. Complete data was available for 73 patients. The prevalence of acute dengue virus infection was 27.6%. The sensitivity and specificity were 88% and 71% respectively. The likelihood of acute dengue infection in the presence of thrombocytopaenia was 2.52 and likelihood of not having dengue infection in normal platelet count patients was 5.22. Thrombocytopaenia has fair predictive value in diagnosing acute dengue virus infection. It was more useful to exclude than to diagnose dengue infection.
Study site: Primary Care Centre of Hospital Universiti
Kebangsaan Malaysia (HUKM) and Batu 9 Health Clinic Hulu Langat,
The diagnosis of prostatic carcinoma (Pca) on routine biopsies may be challenging, and to date the commonly used marker to distinguish prostate carcinoma from benign prostatic lesions has been High Molecular Weight-Cytokeratin (HMW-CK). However, the antigen of HMW-CK is susceptible to the effect of formalin fixation and causes frequent loss or patchy staining in the obviously benign glands. More recently, antibodies to p63 have been reported to be more sensitive than HMW-CK for the detection of prostatic basal cells. p63, a homologue of tumour suppressor gene p53, is essential for prostate development and is selectively expressed in the nuclei of basal cells of normal prostate glands. The objective of this study is to compare the sensitivity and specificity of HMW-CK and p63 in distinguishing prostatic carcinomas from benign prostatic lesions, as well as determining their positive predictive values. Seventy-two cases from HUKM (comprising 29 prostatic carcinomas and 43 benign prostatic hyperplasias) were stained for both HMW-CK and p63. The sensitivity of p63 and HMW-CK in identifying basal cells in benign glands was 88.37% and 90.70% respectively. The specificity of both reagents was 100%, and the positive predictive value for both reagents was also 100%. Thus, p63 is a useful complementary basal cell specific stain to HMW-CK, and would be very helpful to practicing pathologists in dealing with difficult cases.
Ultrasonographic cervical length assessment is increasingly being utilized clinically to identify women at risk for spontaneous preterm delivery. In a randomised prospective longitudinal study involving 200 women, we measured cervical length and internal os diameter by transvaginal scan at 20 - 24 weeks and analysed their ability to predict preterm birth. The risk of spontaneous preterm delivery increased steeply as cervical length decreased. At cut off value of < or = 2.5cm, the cervical length measurements had sensitivity, specificity, positive predictive value and negative predictive value of 77%, 95%, 56% and 98% respectively. However, internal os diameter lacked sensitivity and specificity. Our data suggests that the duration of pregnancy is directly related to length of the cervix: the shorter the cervix, the greater the chance of preterm delivery.
Hand grip strength measurement is a recognized part of hand function assessment. The standard measurement using the Jamar dynamometer and comparing these results to the recommended normal values suggested by the manufacturers of the Jamar was questioned as these values were based on Western population. A study comparing a novel method of predicting grip strength using our software was conducted on 25 normal subjects using the LIDO kinetic workset (Group A and B ). These results were then compared against our predictive software (Group A) and the expected values supplied together with the Jamar Dynamometer (Group B). In another group, 22 normal subjects were tested using the Jamar (Group C and D) and then matched against the predicted values using their recommended chart (Group C). The last group (Group D) was tested using the Jamar but the values attained were compared to the results from our software. In group A, the predictability of our predictive method was 100% (both R & L) as compared to (R = 64%, L = 68%) in group B, (R = 27.3%, L = 59.1%) in group C and (R = 81.8%, L = 86.4%) in group D. The differences between the predictability of both methods were statistically significant. The data collected using both the Jamar and the LIDO kinetic workset correlated well to the data from our software but not to the values suggested by the manufacturers of Jamar. We conclude that our method of predicting hand grip values are superior to that suggested by the manufacturers of dynamometers. The standard reference for hand grip strength provided by the manufacturers is less accurate in predicting the grip strength of our local population.
Prospective evaluation of repeated standard tourniquet testing as a diagnostic indicator of dengue infection was done. Included were patients admitted to a children's hospital in Kuala Lumpur on a clinical suspicion of dengue infection based on the World Health Organization (WHO) criteria. A standard method of tourniquet was performed on 79 patients on a daily basis following admission. subjects and negative in the remaining 14 subjects. Fifty-eight subjects were serologically confirmed cases, 4 indeterminate and the remaining 17 subjects had negative serology. For diagnostic classification, 13 had dengue fever, 49 with dengue haemmorhagic fever (DHF) while 17 had non-dengue infection. The sensitivity and specificity of the tourniquet test was 82.8% and 23.5% respectively. The positive predictive value (PPV) was 78.7% while the negative predictive value (NPV) was 28.6%. In addition, the tourniquet test aided in the diagnosis of one-fifth of patients with DHF, who presented with a positive tourniquet test as the only bleeding manifestation. It seems that in a hospital setting, the tourniquet test adds little to the diagnosis of dengue infection/DHF. A positive tourniquet test, repeatedly performed, was found clinically useful as a preliminary screening test in dengue infection as recommended by WHO. However, it was not very specific and had a high false positive rate.
This study was done to determine the correlation between glucose monitoring by fasting blood glucose or 2 hours postprandial blood glucose with HbA1c and fructosamine in type 2 diabetic patients. A total of 82 patients from the Primary Care Clinic were enrolled in the study. Fasting blood was drawn for fasting plasma glucose (FPG), glycated haemoglobin (HbA1c) and fructosamine. Two hours after a standard breakfast, blood was again drawn for prandial plasma glucose (PPG). Both PPG and FPG significantly correlated with both HbA1c and fructosamine but PPG showed better correlation to HbA1c than FPG (r= 0.604 vs.0.575) whereas that of FPG and PPG were equally correlated to fructosamine (r= 0.566 vs. 0.551). In predicting good glycaemic control (HbA1c < 7.0%), the sensitivity, specificity and positive predictive value of PPG were 75.0%, 80.6% and 82.5% whereas FPG were 81.8%, 58.3% and 70.6% respectively. These results show that PPG correlated better than FPG to HbA1c and both equally correlated to fructosamine levels. Thus, PPG predicted overall glycaemic control better than FPG. Compared to HbA1c, fructosamine correlated least well with mean glucose profiles. Hence, using HbAlc in monitoring overall glycaemic control is better than fructosamine.
The accuracy of multi-detector computed tomographic (MDCI) coronary angiography (CTA) is dependant on image quality as well as the experience of the operator. Established centers have reported negative predictive values of over 95%. The aim of our study was to investigate the accuracy and feasibility of CTA for the assessment of haemodynamically significant coronary stenosis in a center with very early experience (<6 months) utilizing the improved spatial and temporal resolutions of the latest generation 64-row MDCI scanner. One hundred and twenty eight patients (93 male, 35 female; mean age 56.2 +/- 9.5 years) with suspected or known coronary artery disease underwent both CIA and conventional coronary angiographv (CCA). The sensitivity, specificity, positive (PPV) and negative (NPV) predictive values for stenoses > or =50% by CIA compared to CCA were 70%, 97%, 70% and 97% respectively. Evaluation of main and proximal segments in patients with good quality images (78% of patients) produced values of 94%, 95%, 74% and 99% respectively. The improved spatial and temporal resolutions of 64-row MJ) CT provided a high negative predictive value in assessing significant coronary artery stenosis even in a centre with very early experience. However, new centers embarking on CTA might not be able to reproduce the results reported by more experienced centers.
Acute coronary syndrome (ACS) patients with positive troponin T (TnT) test are at higher risk for death and myocardial reinfarction. They would significantly benefit from early aggressive pharmacologic and invasive therapy. However, TnT test is not widely available. This retrospective study of 173 patients with ACS showed: that prolonged or repetitive episodes of angina at rest in the previous 24 hours (p = 0.01) and evidence of myocardial ischaemia on ECG (p < 0.001) were associated with positive TnT tests (> or = 0.1 ng/mL). The two variables in combination showed 100% positive predictive value, facilitating early identification and streamlining of therapy.
The aim of the study was: to obtain the profile of patients (with regards to age and family history of breast cancer) with a palpable breast mass. To determine the validity of ultrasound in the assessment of the palpable breast mass by determining the sensitivity, specificity, positive predictive value, negative predictive value and accuracy of ultrasound in distinguishing a malignant mass. To determine the most discriminating ultrasound characteristics for differentiating benign and malignant masses. Seventy patients who had fine needle aspiration cytology of a palpable breast mass were subjected to an ultrasound assessment of the mass. The ultrasound findings were classified as benign, indeterminate or malignant. These findings were then compared with either the cytology or histology results in cases that eventually had surgical excision. The age of the patients ranged from 15 to 66 years old The majority was in the third and fourth decades with an average age of 25 years. The 8 patients with a proven malignant breast mass were aged between 39 and 66 years old. They did not have any family history of breast cancer. Only 4 patients had a family history of breast carcinoma and all proved to have a benign breast lesion. Ultrasound had a sensitivity of 100%, specificity of 85.7%, positive predictive value of 50%, negative predictive value of 100% and accuracy of 87.5% for distinguishing a malignant mass. For benign masses: 93.7% had well-defined margins, 81.3% had homogenous internal echoes, 91.7% had depth-width ratio of less than 1.0 and 89% were compressible. For malignant masses: 87.5% had either ill-defined or irregular margins, 87.5% had inhomogenous internal echoes and mixed posterior echoes, and 100% were incompressible. The majority of patients with a palpable breast mass were aged below 40 years old. Most of the patients with a malignant breast mass were aged 40 years and older. Neither a positive nor a negative family history of breast cancer had any significance on outcome. Ultrasound had high sensitivity, specificity and accuracy in distinguishing a malignant mass. The most discriminating benign ultrasound characteristic was compressibility. The most discriminating malignant ultrasound characteristic was ill-defined and irregular margins.
OBJECTIVE: Contrast-enhanced ultrasound has become increasingly utilised as an alternative imaging modality for the diagnosis of vesicoureteric reflux (VUR) in paediatric patients. The study objective is to evaluate the efficacy of contrast enhanced Voiding Urosonography (ce-VUS) compared with fluoroscopic micturating cystourethrography (MCU) in the detection of VUR.
METHODS: This prospective study was carried out between July 2011 and January 2013 on paediatric patients who underwent MCU. All consented patients would undergo ce- VUS prior to MCU. We documented the epidemiology details, the number of Kidney-Ureter (K-U) unit studied, baseline renal and bladder sonogram, as well as presence of VUR on ce-VUR. The technique for ce-VUS was standardized using normal saline to fill the bladder prior to administration of SonoVue® (2.5 ml) to assess the kidney-ureter (K-U) unit. Dedicated contrast detection software was used to discern the presence of microbubbles in the pelvicaliceal system (PCS). The findings were then compared with MCU.
RESULTS: 27 paediatric patients were involved in the study [17 males (63%) and 10 females (37%)] involving 55 K-U units (one patient had a complete duplex system). MCU detected VUR in 10 K-U units while ce-VUS detected VUR in 8 out of the 10 K-U units. There were 2 false negative cases (both Grade 1) with ce-VUS. The sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of ce-VUS were 80%, 98%, 95%, 89% and 96%, respectively.
CONCLUSION: ce-VUS is a sensitive and specific radiation-free alternative for the detection of VUR in the paediatric population.