Exact Logistic Regression for a Matched Pairs case-Control Design with Polytomous Exposure Variables

Logistic regression methods are useful in estimating odds ratios under matched pairs case-control designs when the exposure variable of interest is binary or polytomous in nature. Analysis is typically performed using large sample approximation techniques. When conducting the analysis with polytomous exposure variable, situations where the numbers of discordant pairs in the resulting cells are small or the data structure is sparse can be encountered. In such situations, the asymptotic method of analysis is questionable, thus an exact method of analysis may be more suitable. A method is presented that performs exact inference in the case of pair-wise matched case-control data with more than two unordered exposure categories using a distribution of conditional sufficient statistics of logistic model parameters

Perception of stroke and knowledge of potential risk factors among Omani patients at increased risk for stroke

BACKGROUND: Previous studies have demonstrated poor knowledge of stroke among patients with established risk factors. This study aims to assess the baseline knowledge, among patients with increased risk for stroke in Oman, of warning symptoms of stroke, impending risk factors, treatment, and sources of information. METHODS: In April 2005, trained family practice residents at Sultan Qaboos University Hospital Clinics (cardiology, neurology, diabetic, and lipid clinics), using a standardised, structured, pre-tested questionnaire, conducted a survey of 400 Omani patients. These patients all demonstrated potential risk factors for stroke. RESULTS: Only 35% of the subjects stated that the brain is the organ affected by a stroke, 68% correctly identified at least one symptom/sign of a stroke, and 43% correctly identified at least one stroke risk factor. The majority (62%) did not believe they were at increased risk for stroke, and 98% had not been advised by their attending physician that their clinical conditions were risk factors for stroke. In the multivariable logistic regression analysis, lower age and higher levels of education were associated with better knowledge regarding the organ involved in stroke, stroke symptoms, and risk factors. CONCLUSION: Because their knowledge about stroke risk factors was poor, the subjects in this study were largely unaware of their increased risk for stroke. Intensive health education is needed to improve awareness of stroke, especially among the most vulnerable groups

Prevalence of prehypertension and associated cardiovascular risk profiles among prediabetic Omani adults

<p>Abstract</p> <p>Background</p> <p>The importance of prediabetes and prehypertension has been demonstrated in several studies especially for primary prevention of CVD. A recent community based cross-sectional study revealed that 40.9 percent Omani adults are prediabetics. This study was undertaken to estimate the prevalence of prehypertension and associated cardiovascular risk profiles in prediabetics. To best of our knowledge, this is the first report on this subject.</p> <p>Methods</p> <p>The study included 327 confirmed pre-diabetic Omani adults, who were analysed for their demographic, metabolic and behavioral characteristics. These characteristics were compared between the three different blood pressure groups to determine the CVD risk factors. Univariate and step-wise multiple logistic regression methods were used to carry out the analysis of the data.</p> <p>Results</p> <p>In this study, the prevalence of prehypertension was 54.1 percent. Males were at higher risk of developing prehypertension as compared to females (OR = 2.30, 95% CI: 1.21, 4.38; P < 0.01). The individuals with higher BMI have two fold more risk of developing prehypertension (OR = 2.25, 95% CI: 1.26, 4.02; P < 0.01). The increased level of OGT enhanced the risk of developing prehypertension (OR = 1.26, 95% CI: 1.06, 1.50; P < 0.01).</p> <p>Conclusion</p> <p>A high prevalence of prehypertension (54.1%) exists in this study population. The major determinants of prehypertension in these prediabetic subjects were male gender, increasing dysglycemia and BMI. Appropriate intervention strategies have been suggested.</p

Knowledge and perceptions of diabetes in a semi-urban Omani population

<p>Abstract</p> <p>Background</p> <p>Diabetes mellitus is a major public health problem in the Sultanate of Oman. This study aimed to evaluate the knowledge and perception of diabetes in a sample of the Omani general population, and the associations between the elements of knowledge and perception, and socio-demographic factors.</p> <p>Methods</p> <p>The study was carried out in two semi-urban localities. A total of 563 adult residents were interviewed, using a questionnaire specifically designed for the present study. In addition to demographic information, the questionnaire contained questions on knowledge related to diabetes definition, symptoms, risk factors, complications and preventative measures, as well as risk perception for diabetes.</p> <p>Results</p> <p>Knowledge of diabetes was suboptimal. The percentages of correct responses to questions on diabetes definition, classical symptoms, and complications were 46.5%, 57.0%, and 55.1%, respectively. Only 29.5%, 20.8% and 16.9% identified obesity, physical inactivity and a positive family history, respectively, as risk factors for diabetes. A higher level of education, a higher household income, and the presence of a family history of diabetes were found to be positively associated with more knowledge.</p> <p>Conclusion</p> <p>This study demonstrated that there is lack of awareness of major risk factors for diabetes mellitus. Level of education is the most significant predictor of knowledge regarding risk factors, complications and the prevention of diabetes. Given that the prevalence of diabetes has increased drastically in Oman over the last decade, health promotion seems essential, along with other means to prevent and control this emerging health problem.</p

Patients’ Views of Interpersonal Continuity of Care in Four Primary Health Care Centres of Urban Oman

Objectives: Interpersonal continuity of care (consulting the same physician) is widely regarded as a core value of primary care and a crucial component of quality of care. Nonetheless, interpersonal continuity as experienced by patients remains a neglected topic in Arab countries including Oman. The aim of this study was to explore how patients view interpersonal continuity of care in the primary care setting in Oman. Methods: Four primary health centres (PHCs) were selected from two urban cities in Oman. In the period June to August 2008, adult patients were surveyed by questionnaire at their PHC while waiting to see their primary care physicians (PCPs). Results: We interviewed 319 (71%) of enrolled participants. Their ages ranged from 18-70 years. The majority of patients (223 - 70%) thought interpersonal continuity was very important for them; 232 (73%) patients felt that they obtained better care with interpersonal continuity. 225 (71%) patients preferred interpersonal continuity if they had personal, family or social problems. Nonetheless, compared to male patients, female patients had less chance to maintain interpersonal continuity (p = 0.018). Interpersonal continuity increased as the number of consultations increased (p = 0.030). Preference for interpersonal continuity was associated with increasing age (p = 0.020) and with the presence of chronic illnesses (p = 0.001). Patients with chronic illnesses, who reported more preference for interpersonal continuity, were also found to be more compliant with medications and committed to carrying out recommended advice compared to patients without such illnesses (p = 0.027). Conclusion: Omani patients perceived interpersonal continuity as an important aspect of primary care. Health planners should note patients’ preference for interpersonal continuity and take visible measures to support it. A larger study is needed to survey more of the PHCs of Oman

Some Risk Factors for Coronary Heart Disease among Omani Males A matched case-control study

 Objectives: Evaluation of some of the leading risk factors for coronary heart disease (CHD) among males in Oman. Methods: We conducted a hospital-based pair-wise matched case-control study among Omani CHD patients admitted in the Sultan Qaboos University Hospital and the Royal Hospital located in Muscat, Oman. The cases were matched with an equal number of controls in respect of age and hospital. The information was collected from the cases and controls based on an interview and review of the medical records of the admitted CHD patients. The odds ratios (ORs) were estimated under univariate as well as multivariate situations using conditional multiple binary logistic regression model. Results: The analysis revealed that 74 percent of the cases were of angina pectoris. The majority of the cases (96%) were above 40 years of age. The prevalence of sedentary life style was predominant (88.0%). Hypertension, diabetes, family history of CHD and a sedentary occupation were the most significant risk factors for the development of the disease. The estimated values of the adjusted ORs were found to be 9.98, 2.74, 28.19 and 3.00 respectively (p&lt;0.05). Conclusion: Individuals with hypertension, diabetes mellitus, a family history of CHD and with sedentary occupations are to be considered at high risk of developing CHD. Such individuals should be provided with appropriate health education along with close monitoring for symptoms and signs of CHD.

Some Risk Factors for Coronary Heart Disease among Omani Males: A matched case-control study

 Objectives: Evaluation of some of the leading risk factors for coronary heart disease (CHD) among males in Oman. Methods: We conducted a hospital-based pair-wise matched case-control study among Omani CHD patients admitted in the Sultan Qaboos University Hospital and the Royal Hospital located in Muscat, Oman. The cases were matched with an equal number of controls in respect of age and hospital. The information was collected from the cases and controls based on an interview and review of the medical records of the admitted CHD patients. The odds ratios (ORs) were estimated under univariate as well as multivariate situations using conditional multiple binary logistic regression model. Results: The analysis revealed that 74 percent of the cases were of angina pectoris. The majority of the cases (96%) were above 40 years of age. The prevalence of sedentary life style was predominant (88.0%). Hypertension, diabetes, family history of CHD and a sedentary occupation were the most significant risk factors for the development of the disease. The estimated values of the adjusted ORs were found to be 9.98, 2.74, 28.19 and 3.00 respectively (p&lt;0.05). Conclusion: Individuals with hypertension, diabetes mellitus, a family history of CHD and with sedentary occupations are to be considered at high risk of developing CHD. Such individuals should be provided with appropriate health education along with close monitoring for symptoms and signs of CHD.

Insulin-Like Growth Factor 1 Gene polymorphism and Breast cancer Risk Among Arab Omani Women:A case-control study

Breast cancer is the most common cancer worldwide with significant global burden. Insulin-like growth factor 1 (IGF1) is an important regulator of cellular growth, differentiation, and apoptosis and mitogenic and antiapoptotic activities. Some studies suggested an association between cytosine adenine (CA) repeats gene polymorphisms of IGF1 and the risk of developing breast cancer while other studies did not find such an association. This study aims investigate the role of IGF1 (CA) repeats gene polymorphisms in the risk of developing breast cancer among Omani women. Methods We analyzed (CA) repeats gene polymorphisms of IGF1 by extraction of genomic DNA from the peripheral blood of 147 patients with breast cancer and 134 control participants and performed genotyping using DNA sequencing. Results Approximately 46% of patients carried the IGF (CA) 19 repeat allele, with 31.3% carrying two copies of this allele and 50% of controls carried the IGF (CA) 19 repeat allele with 30.1% carrying two copies of this allele. The difference of the IGF CA repeat groups was significant between cases and controls with ( P = 0.02). In contrast, there was no difference in the distribution of (CA) 19 repeat allele, (CA) 18 repeat allele and (CA) 19 repeat allele between cases and controls. The difference of the CA groups was significant between cases and controls among postmenopausal women with ( P = 0.026), whereas no difference was observed among postmenopausal subjects ( P = 0.429). In both pre- and postmenopausal groups there was no difference in the distribution of (CA) 19 repeat allele, (CA) 18 repeat allele and (CA) 20 repeat allele between patients and control subjects. On further IGF1 genotypes classification, we found an association between progesterone receptor status and the genotypes group where the non carrier of (CA) 19 repeat group was compared to (CA) 19 repeat carrier group (OR = 2.482; 95% CI = 1.119–5.503; P value = 0.023). Conclusion Overall there was no association between the IGF (CA) 19 repeat and breast cancer in Omani females