Statistical analysis of longitudinal randomized clinical trials with missing data: a comparison of approaches

Objectives Missing data represent a source of bias in randomized clinical trials (RCTs). This thesis focuses on pragmatic RCTs with missing continuous outcome data and evaluates the use and appropriateness of current methods of analysis. Methods This thesis consists of three parts. First, a systematic review examined practices relating to missing data in published RCTs. Second, a simulation study compared the performance of various methods for handling missing data in a number of plausible trial scenarios. Finally, an empirical evaluation of two pragmatic RCTs investigated the use of a reminder process to inform whether missingness is likely to be non-ignorable. Results The majority of 91 trials in the systematic review adopted a form of single imputation, such as last observation carried forward (LOCF) for dealing with missing data. Mixed-effects model for repeated measures (MMRM) and/or multiple imputation (MI) were limited to eight trials. Sensitivity analyses were infrequently and inappropriately used, and insufficiently reported. In the simulation study, LOCF yielded biased estimates of treatment effect in most scenarios, irrespective of missing data mechanisms. All methods, except LOCF, yielded unbiased estimates for scenarios of equal dropout rate and same direction of dropout in both treatment groups. MMRM and MI were more robust to bias than complete-case and LOCF-based analyses. In the empirical study, the evaluation using reminder responses indicated the possibility of biased MMRM estimation in one trial and unbiased MMRM estimation in the other. Conclusion CCA and LOCF-based analysis should be disregarded in favour of methods such as MMRM and MI-based analysis. The proposed reminder approach can be used to assess the robustness of the missing at random (MAR) assumption by checking expected consistency in MAR-based estimates. If the results deviate, then analyses incorporating a range of plausible missing not at random assumptions are advisable, at least as sensitivity tests for the evaluation of treatment effect

Health-related quality of life among patients with type 2 diabetes mellitus in Eastern Province, Saudi Arabia: A cross-sectional study.

Diabetes mellitus has reached epidemic levels, and it threatens the economy and health globally and Saudi Arabia in particular. The study assessed health-related quality of life using EuroQol instrument and its predictors among patients with Type 2 diabetes mellitus in Eastern Province, Saudi Arabia. A cross-sectional study was conducted among 378 patients with Type 2 diabetes mellitus from two major health centers in Eastern Province. The study showed moderate health-related quality of life, as reported by the median index score of 0.808 with more than a quarter of patients with severe-extreme health state in some or all domains. Multiple-regression models showed that male gender, high monthly income, having no diabetes-related complications and having random blood glucose level less than 200 mg/dl were prone to have a higher index score compared to the corresponding contrary groups. The study will help in guiding the development of effective intervention programs to improve diabetes-related health-related quality of life among the Saudi population

Efficacy of Core Training in Swimming Performance and Neuromuscular Parameters of Young Swimmers: A Randomised Control Trial

Background: This study aimed to investigate the efficacy of core training in the swimming performance and neuromuscular properties of young swimmers. Methods: Eighteen healthy male swimmers (age: 13 ± 2 years, height: 159.6 ± 14.5 cm, weight: 48.7 ± 12.4 kg) were recruited from the Public Authority for Sports swimming pool in Dammam and randomly assigned to the experimental and control groups. The experimental group performed a six-week core-training program consisting of seven exercises (three times/week) with regular swimming training. The control group maintained its regular training. Swimming performance and neuromuscular parameters were measured pre- and post-interventions. Results: The experimental group benefitted from the intervention in terms of the 50 m swim time (−1.4 s; 95% confidence interval −2.4 to −0.5) compared with the control group. The experimental group also showed improved swimming velocity (+0.1 m.s−1), stroke rate (−2.8 cycle.min−1), stroke length (+0.2 m.cycle−1), stroke index (+0.4 m2·s−1), total strokes (−2.9 strokes), and contraction time for erector spinae (ES; −1.5 ms), latissimus dorsi (LD; −7 ms), and external obliques (EO; −1.9 ms). Maximal displacement ES (DM-ES) (+3.3 mm), LD (0.5 mm), and EO (+2.2 mm) were compared with the baseline values for the experimental group, and TC-ES (5.8 ms), LD (3.7 ms), EO (2.5 ms), DM-ES (0.2 mm), LD (−4.1 mm), and EO (−1.0 mm) were compared with the baseline values for the control group. The intergroup comparison was statistically significant (p p > 0.05). Conclusion: The results indicate that a six-week core-training program with regular swimming training improved the neuromuscular properties and the 50 m freestyle swim performance of the experimental group compared with the control group

Short-Term Effects of Dry Needling with a Standard Exercise Program on Pain and Quality of Life in Patients with Chronic Mechanical Neck Pain

Background: This study aimed to determine the short-term effects of dry needling (DN) combined with a standard exercise program on pain and quality of life in patients with chronic mechanical neck pain (CMNP). Methods: Thirty-one patients with CMNP were randomly allocated to the experimental and control groups. The experimental group received DN and underwent a standard exercise program (one DN session and six exercise sessions) for two weeks, whereas the control group underwent the same exercise program alone for two weeks. The participants’ scores in the Numeric Pain Rating Scale (NPRS), Neck Disability Index (NDI), Short Form-36 Quality of Life Scale (SF-36 QOLS), and Beck Depression Inventory (BDI) before and after the intervention were assessed. Results: The control and experimental groups’ post-test NDI, NPRS, SF-36 QOLS, and BDI scores significantly differed from their baseline scores (p ≤ 0.05). The between-group comparison of the post-test scores using Wilcoxon rank-sum test revealed no significant differences between the NDI, NPRS, BDI, and SF-36 QOLS scores of both groups (p ≥ 0.05). Conclusions: One session of trigger point DN (TrP-DN) with exercise and exercise alone showed the same pain and quality-of-life outcomes after a two-week intervention. We did not recognise TrP-DN as an efficient intervention, not because we obtained evidence that it is ineffective, but because there were inadequate high-quality studies on the subject and unavailable data on the minimum quantity of injections required for better DN outcomes in CMNP patients

Awareness of statin–food interactions using grapefruit as an example: a cross-sectional study in Eastern Province of Saudi Arabia

Abstract Objectives The purpose of this study is to assess patients’ knowledge regarding statin–grapefruit interactions, to identify any pertinent demographic characteristics that may influence knowledge of this drug–food interaction, and to identify preferred patient sources of health information. Methods A cross-sectional study was conducted to collect data from statins users about the awareness regarding drug interaction with foods. Self-administered questionnaires have been distributed to collect data from statins users regardless of the type and the reason they administer these medications. Respondents were statins users visiting the King Fahd Hospital’s outpatient clinic (KFHU) and community pharmacies in the Eastern province of Saudi Arabia. Key findings Our study revealed that 62% of statin users never heard about the statin–grapefruit interaction. Only 11% have correctly recognized the interaction effect. Only 11, 21 and 6% of users have reported that they often/always received information on drug–food interaction from pharmacists, physicians and nurses, respectively. Users aged above 60 years had lower awareness than those aged <40 (6.0% vs. 14.1%). Similarly, the proportion was lower among users who had primary or lower educational attainment, unemployed or had income lower than 5000 SAR compared with that among the contrary groups. However, only income showed a statistically significant association (P = 0.007). Conclusions The majority of statin users have never heard about their interaction with food. Geriatrics, low-income and less educated patients had a lower level of awareness compared with their counterparts. Many patients may end up discontinuing their medications because of that interaction and the consequent side effects. Pharmacists are requested to play their expected role in providing adequate patient counselling to help improve patients’ awareness regarding safety concerns of statins medication

Exploring the perception and readiness of Pharmacists towards telepharmacy implementation; a cross sectional analysis

Background Amid the turbulent nature of the COVID-19 pandemic, telepharmacy has shifted the paradigm of patient care by leveraging digital medicine. Government mandated lockdowns and norms of social distancing have further underscored the need for telepharmacy. Many developed and developing countries implemented such initiatives where pharmacists have provided tele-pharmacy services via telecommunications. However, the implementation and utilization of tele-pharmacy services are quite negligible in resource limited settings due to financial and administrative constraints. This study was aimed to ascertain the perception and readiness of pharmacists working in various sectors of a resource limiting country. Methodology A cross sectional study was carried out in all provinces of Pakistan to explore the perceptions of pharmacists towards telepharmacy implementation through a 35-items study instrument. The collected data was analyzed descriptively and scored accordingly. The chi-square test was used for inferential analysis on pharmacist’s perception regarding implementation of tele-pharmacy with their demographics. Results Of 380 pharmacists, the mean age is 27.67 ± 3.67 years with a preponderance of male pharmacists (n = 238, 62.6%). The pharmacists (n = 321, 84.5%) perceived that telepharmacy implementation improves patient’s quality of life and decreases patients’ visits (n = 291, 76.6%). Overall, pharmacists (n = 227, 59.7%) had negative perception towards benefits of telepharmacy implementation, but pharmacists had positive perception towards eligibility (n = 258, 67.9%), regulatory issues (n = 271, 71.3%) and telepharmacy during pandemic and beyond (n = 312, 82.1%). In chi-square testing gender (p = 0.03) and age (p = 0.03) had a significant association with perception regarding regulatory issues. Among perception regarding telepharmacy during COVID-19 pandemic and beyond age had a significant association (p = 0.03). Among perception regarding eligibility job location of pharmacists had significant association (p = 0.04). Conclusion The majority of pharmacists had a positive perception regarding the eligibility of patients and regulatory issues/legal framework regarding the implementation of tele-pharmacy, as well as its use during the COVID-19 pandemic and beyond. The implementation of tele-pharmacy can play a major role in providing timely and better patient care to remote patient areas and may help in the prevention and treatment of different infectious diseases