BackgroundAnalysis of variance (ANOVA), change-score analysis (CSA) and analysis of covariance (ANCOVA) respond differently to baseline imbalance in randomized controlled trials. However, no empirical studies appear to have quantified the differential bias and precision of estimates derived from these methods of analysis, and their relative statistical power, in relation to combinations of levels of key trial characteristics. This simulation study therefore examined the relative bias, precision and statistical power of these three analyses using simulated trial data.Methods126 hypothetical trial scenarios were evaluated (126 000 datasets), each with continuous data simulated by using a combination of levels of: treatment effect; pretest-posttest correlation; direction and magnitude of baseline imbalance. The bias, precision and power of each method of analysis were calculated for each scenario.ResultsCompared to the unbiased estimates produced by ANCOVA, both ANOVA and CSA are subject to bias, in relation to pretest-posttest correlation and the direction of baseline imbalance. Additionally, ANOVA and CSA are less precise than ANCOVA, especially when pretest-posttest correlation ≥ 0.3. When groups are balanced at baseline, ANCOVA is at least as powerful as the other analyses. Apparently greater power of ANOVA and CSA at certain imbalances is achieved in respect of a biased treatment effect.ConclusionsAcross a range of correlations between pre- and post-treatment scores and at varying levels and direction of baseline imbalance, ANCOVA remains the optimum statistical method for the analysis of continuous outcomes in RCTs, in terms of bias, precision and statistical power.

The clinical course for LBP with self-reported referred leg pain is much worse. However, the fact that differences in outcome were not worse after adjustment suggests that baseline differences in severity and duration of back pain, demographic, and psychological characteristics largely explain the poorer outcomes in patients with referred leg pain. Future research needs to establish if similar results are observed among patients with clinically determined sciatica.

The study revealed a gap in the knowledge of HIV/AIDS and an inappropriate sexual behaviour among respondents. Meaningful strategies, such as an innovative and culturally sensitive adolescent sexual and reproductive health programme that focuses on modification of sexual behaviour should be adopted to allow young people to prevent transmission of the HIV/AIDS virus.

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Background: Malaria has remained a global burden for many centuries. It remains a major public health disease particularly in the tropic despite several interventional efforts targeted at its elimination. Malaria if not treated early enough could result in patients becoming anaemic. In Nigeria, elderly (60 years and above) represent a vulnerable group of individuals, they enjoy very little attention in terms of specific health related interventions and facilities. This study aimed to assess the prevalence and proportion of asymptomatic malaria infections and anaemia among the geriatric population in Osun state, Southwestern Nigeria.Methods: A community-based cross-sectional study was conducted among 396 elderly with average age of 69.14±7.27 years. Blood samples were collected for the preparation of Giemsa stained blood films for the detection and quantification of malaria parasites microscopically. Packed cell volume (PCV) was assessed using hematocrit.Results: Malaria parasites were present in the peripheral blood of 16.2% of the population and only 9.3% of the elderly were found to be anaemic. The ‘Very old’ age group of >85 years years had highest prevalence of malaria (33.3%) but this was not statistically significant (p=0.17). Male respondents (24.4%) were more infected than females (13.7%) and this was found statistically significant (p=0.015). Having malaria parasite and living in the rural areas were significantly associated with being anaemic, p<0.05 in each case.Conclusions: Considerable proportion of asymptomatic elderly individuals with parasitaemia were found anaemic. This group also represents a silent reservoir for malaria transmission in the country, if not addressed.