Background: The International Physical Activity Questionnaire - Short Form (IPAQ-SF) has been recommended as a cost-effective method to assess physical activity. Several studies validating the IPAQ-SF have been conducted with differing results, but no systematic review of these studies has been reported. Methods: The keywords "IPAQ", "validation", and "validity" were searched in PubMed and Scopus. Studies published in English that validated the IPAQ-SF against an objective physical activity measuring device, doubly labeled water, or an objective fitness measure were included. Results: Twenty-three validation studies were included in this review. There was a great deal of variability in the methods used across studies, but the results were largely similar. Correlations between the total physical activity level measured by the IPAQ-SF and objective standards ranged from 0.09 to 0.39; none reached the minimal acceptable standard in the literature (0.50 for objective activity measuring devices, 0.40 for fitness measures). Correlations between sections of the IPAQ-SF for vigorous activity or moderate activity level/walking and an objective standard showed even greater variability (-0.18 to 0.76), yet several reached the minimal acceptable standard. Only six studies provided comparisons between physical activity levels derived from the IPAQ-SF and those obtained from objective criterion. In most studies the IPAQ-SF overestimated physical activity level by 36 to 173 percent; one study underestimated by 28 percent. Conclusions: The correlation between the IPAQ-SF and objective measures of activity or fitness in the large majority of studies was lower than the acceptable standard. Furthermore, the IPAQ-SF typically overestimated physical activity as measured by objective criterion by an average of 84 percent. Hence, the evidence to support the use of the IPAQ-SF as an indicator of relative or absolute physical activity is weak.

Objective: To examine the effects of home-based transitional palliative care for patients with end-stage heart failure (ESHF) after hospital discharge. Methods: This was a randomised controlled trial conducted in three hospitals in Hong Kong. The recruited subjects were patients with ESHF who had been discharged home from hospitals and referred for palliative service, and who met the specified inclusion criteria. The interventions consisted of weekly home visits/telephone calls in the first 4 weeks then monthly follow-up, provided by a nurse case manager supported by a multidisciplinary team. The primary outcome measures were any readmission and count of readmissions within 4 and 12 weeks after index discharge, compared using χ² tests and Poisson regression, respectively. Secondarily, change in symptoms over time between control and intervention groups were evaluated using generalised estimating equation analyses of data collected using the Edmonton Symptom Assessment Scale (ESAS). Results: The intervention group (n=43) had a significantly lower readmission rate than the control group (n=41) at 12 weeks (intervention 33.6% vs control 61.0% χ²=6.8, p=0.009). The mean number (SE) of readmissions for the intervention and control groups was, respectively, 0.42 (0.10) and 1.10 (0.16) and the difference was significant (p=0.001). The relative risk (CI) for 12-week readmissions for the intervention group was 0.55 (0.35 to 0.88). There was no significant difference in readmissions between groups at 4 weeks. However, when compared with the control group, the intervention group experienced significantly higher clinical improvement in depression (45.9% vs 16.1%, p<0.05), dyspnoea (62.2% vs 29.0%, p<0.05) and total ESAS score (73.0% vs 41.4%, p<0.05) at 4 weeks. There were significant differences between groups in changes over time in quality of life (QOL) measured by McGill QOL (p<0.05) and chronic HF (p<0.01) questionnaires. Conclusions: This study provides evidence of the effectiveness of a postdischarge transitional care palliative programme in reducing readmissions and improving symptom control among patients with ESHF. Trial registration number: HKCTR-1562; Results.

Aims To determine myopia progression in children who continued to wear the defocus incorporated multiple segments (DIMS) lenses or switched from single vision (SV) to DIMS lenses for a 1-year period following a 2-year myopia control trial. Methods 128 children participated in this study. The children who had worn DIMS lenses continued to wear DIMS lenses (DIMS group), and children who had worn SV lenses switched to wear DIMS lenses (Control-to-DIMS group). Cycloplegic spherical equivalent refraction (SER) and axial length (AL) were measured at 6-month interval. Historical controls were age matched to the DIMS group at 24 months and used for comparing the third-year changes. Results Over 3 years, SER and AL changes in the DIMS group (n=65) were −0.52±0.69D and 0.31±0.26 mm; these changes were not statistically significant over time (repeated measures analysis of variance, p>0.05). SER (−0.04±0. 38D) and AL (0.08±0.12 mm) changes in the Control-to-DIMS group (n=55) in the third year were less compared with the first (mean difference=0.45 ± 0.30D, 0.21±0.11 mm, p<0.001) and second (0.34±0.30D, 0.12±0.10 mm, p<0.001) years. Changes in SER and AL in both groups over that period were significantly less than in the historical control group (DIMS vs historical control: mean difference=−0.18±0.42D, p=0.012; 0.08±0.15 mm, p=0.001; Control-to-DIMS versus historical control: adjusted mean differences=−0.30±0.42D, p<0.001; 0.12±0.16 mm, p<0.001). Conclusions Myopia control effect was sustained in the third year in children who had used the DIMS spectacles in the previous 2 years and was also shown in the children switching from SV to DIMS lenses.

Background: When using the change-in-estimate criterion, a cutoff of 10% is commonly used to identify confounders. However, the appropriateness of this cutoff has never been evaluated. This study investigated cutoffs required under different conditions. Methods: Four simulations were performed to select cutoffs that achieved a significance level of 5% and a power of 80%, using linear regression and logistic regression. A total of 10 000 simulations were run to obtain the percentage differences of the 4 fitted regression coefficients (with and without adjustment). Results: In linear regression, larger effect size, larger sample size, and lower standard deviation of the error term led to a lower cutoff point at a 5% significance level. In contrast, larger effect size and a lower exposure–confounder correlation led to a lower cutoff point at 80% power. In logistic regression, a lower odds ratio and larger sample size led to a lower cutoff point at a 5% significance level, while a lower odds ratio, larger sample size, and lower exposure–confounder correlation yielded a lower cutoff point at 80% power. Conclusions: Cutoff points for the change-in-estimate criterion varied according to the effect size of the exposure–outcome relationship, sample size, standard deviation of the regression error, and exposure–confounder correlation.

Sleep disturbance and executive dysfunction have been widely reported in children with autism spectrum disorder. While the positive impacts of physical activity on sleep quality and cognition are documented in children with typical development, similar studies in children with autism spectrum disorder are scarce. The objective of this study was to examine the impact of physical activity on sleep quality and cognition in children with autism spectrum disorder. A total of 40 children diagnosed with autism spectrum disorder (mean age = 9.95 years) were randomly assigned into two groups: physical activity intervention and control. Four sleep parameters (sleep efficiency, sleep onset latency, sleep duration, and wake after sleep onset) and two executive functions (inhibition control and working memory) were assessed. Results revealed a significant improvement in sleep efficiency, sleep onset latency, and sleep duration in the intervention group but not in the control group during weekdays. Moreover, a significant improvement in inhibitory control was shown in the intervention group but not in the control group. No significant improvement in working memory capacity was documented in either group (ps > 0.05). Our findings highlight the value of physical activity in improving sleep quality and cognition among children with autism spectrum disorder, but specific physical activity may be required to benefit individual executive functions.

Sleep disturbance is a complex health problem in ageing global populations decreasing quality of life among many older people. Geographic, cultural, and ethnic differences in sleep patterns have been documented within and between Western and Asian populations. The aim of this study was to explore sleep problems among Hong Kong seniors by examining the prevalence of poor sleep quality, the relationship between sleep quality and health-related quality of life, and associated factors of good sleepers in different age groups.