Intraclass correlation coefficient (ICC) measures the extent of agreement and consistency among raters for two or more numerical or quantitative variables. This review paper aimed to present several tables that could illustrate the minimum sample sizes required for estimating the desired effect size of ICC, which is a measurement of the magnitude of an agreement. Determination of the minimum sample size under such circumstances is based on the two fundamentally important parameters, namely the actual value of the ICC and the number of observations made by each subject. The sample size calculations are derived from Power Analysis and Sample Size (PASS) software where the alpha and minimum required power is fixed at 0.05 and higher than 0.80 respectively. A discussion on how to use these tables for determining sample sizes required for each of the various scenarios and the limitations associated with their use in each of these scenarios is provided.

Objective: We aimed to validate the Malay version of Diabetes Quality of Life (DQOL) questionnaire for Malaysian adult population with type 2 diabetes mellitus (DM). Methods: This is a cross-sectional study to validate Malay version of DQOL among the adult diabetic patients. DQOL questionnaire has 46 items consist of three domains, namely Satisfaction Domain, Impact Domain and Worry Domain. Both forward and backward translations from the English version of DQOL into Malay version were performed. After the face validity of the Malay version was established, it was then pilot-tested. Finally, the validity and reliability of the final Malay version of DQOL questionnaire were evaluated. Results: There were 290 patients participated in this study with a mean (SD) age of 53.1 (10.0) years. The Cronbach's alpha coefficients of the overall items and the main domains were between 0.846 and 0.941. The Pearson's correlation coefficients for the three domains were between 0.228 and 0.451. HbA1C was found to be positively correlated with Impact Domain (P = 0.006). The Worry Domain was associated with diabetic retinopathy (P = 0.014) and nephropathy (P = 0.033). Conclusion: The Malay version of diabetes quality of life (DQOL) questionnaire was found to be a valid and reliable survey instrument to be used for Malaysian adult patients with diabetes mellitus.

Background: Patients with severe psoriasis, namely those requiring phototherapy or systemic treatment, have an increased risk of death. The aim of this study was to determine the prevalence, aetiology and risk factors for mortality among adult patients aged 18 years and above with psoriasis in Malaysia. Methods: This was a retrospective study involving adult patients notified by dermatologists to the Malaysian Psoriasis Registry between July 2007 and December 2013. Data were cross-checked against the National Death Registry. Patients certified dead were identified and the cause of death was analysed. Multivariate analysis using multiple logistic regression were conducted on potential factors associated with higher risk of mortality. Results: A total of 419 deaths were identified among the 9775 patients notified. There were four significant risk factors for higher mortality: age>40 years (age 41-60 years old, Odds Ratio (OR) 2.70, 95%CI 1.75, 4.18; age>60 years OR 7.46, 95%CI 4.62, 12.02), male gender (OR 1.72, 95%CI 1.33,2.22), severe psoriasis with body surface area (BSA) >10% (OR 1.52, 95%CI 1.19, 1.96) and presence of at least one cardiovascular co-morbidity (OR 1.67, 95% CI 1.30, 2.14). Among the 301 patients with verifiable causes of death, the leading causes were infection (33.9%), cardiovascular disease (33.6%) and malignancy (15.9%). Conclusion: Infection was the leading cause of death among psoriasis patients in Malaysia. Although cardiovascular diseases are well-known to cause significant morbidity and mortality among psoriasis patients, the role of infections and malignancy should not be overlooked.
Psoriasis