The relationship between individual-level deprivation and health-related quality of life.

OBJECTIVE: To examine the association between individual-level deprivation and health-related quality of life (HRQL) in the general population. METHODS: Data from a population-based survey in the Canadian province of Alberta were used. Individual-level deprivation was assessed using the Canadian Deprivation Index (CDI) and the Ontario Deprivation Index (ODI). HRQL was assessed using the EQ-5D-5 L. Differences in problems in the EQ-5D-5 L dimensions, index and visual analogue scale (VAS) scores across levels of deprivation were examined. Multivariate logistic and linear regression models adjusted for socio-demographic and other characteristics were used to examine the independent association between deprivation and HRQL. RESULTS: Of the 6314 respondents, 39% were aged between 18 and 44 years and 38% between 45 and 64 years; 60% were female. Mean EQ-5D-5 L index and VAS scores were 0.85 (standard deviation [SD] 0.14) and 79.6 (SD 17.7), respectively. Almost one-third (30.6%) of respondents reported no problems on all EQ-5D-5 L dimensions. Few participants reported some problems with mobility (23.8%), self-care (6.2%) and usual activities (25.2%), while 59.3 and 35.5% reported some levels of pain/discomfort and anxiety/depression, respectively. Differences between the most and least deprived in reporting problems in EQ-5D-5 L dimensions, index and VAS scores were statistically significant and clinically important. In adjusted regression models for both deprivation indices, the least well-off, compared to the most well-off, had higher likelihood of reporting problems in all EQ-5D-5 L dimensions. Compared to the most well-off, the least well-off had an EQ-5D-5 L index score decrement of 0.18 (p < 0.01) and 0.17 (p < 0.01) for the CDI and ODI, respectively. Similarly, an inverse association was found between the VAS score and the CDI (ß = - 17.3, p < 0.01) as well as the ODI (ß = - 13.3, p < 0.01). CONCLUSION: Individual-level deprivation is associated with worse HRQL. Poverty reduction strategies should consider the effects of not only neighbourhood-level deprivation, but also that of individual-level deprivation to improve overall health.

Maternal vitamin D supplementation during pregnancy and lactation to prevent acute respiratory infections in infancy in Dhaka, Bangladesh (MDARI trial): protocol for a prospective cohort study nested within a randomized controlled trial.

BACKGROUND: Early infancy is a high-risk period for severe acute respiratory infection (ARI), particularly in low-income countries with resource-limited health systems. Lower respiratory tract infection (LRTI) is commonly preceded by upper respiratory infection (URTI), and often caused by respiratory syncytial virus (RSV), influenza and other common community-acquired viral pathogens. Vitamin D status is a candidate modifiable early-life determinant of the host antiviral immune response and thus may influence the risk of ARI-associated morbidity in high-risk populations. METHODS/DESIGN: In the Maternal Vitamin D for Infant Growth (MDIG) study in Dhaka, Bangladesh (NCT01924013), 1300 pregnant women are randomized to one of five groups: placebo, 4200 IU/week, 16,800 IU/week, or 28,000 IU/week from 2nd trimester to delivery plus placebo from 0-6 months postpartum; or, 28,000 IU/week prenatal and until 6-months postpartum. In the Maternal Vitamin D for ARI in Infancy (MDARI) sub-study nested within the MDIG trial, trained personnel conduct weekly postnatal home visits to inquire about ARI symptoms and conduct a standardized clinical assessment. Supplementary home visits between surveillance visits are conducted when caregivers make phone notifications of new infant symptoms. Mid-turbinate nasal swab samples are obtained from infants who meet standardized clinical ARI criteria. Specimens are tested by polymerase chain reaction (PCR) for 8 viruses (influenza A/B, parainfluenza 1/2/3, RSV, adenovirus, and human metapneumovirus), and nasal carriage density of Streptococcus pneumoniae. The primary outcome is the incidence rate of microbiologically-positive viral ARI, using incidence rate ratios to estimate between-group differences. We hypothesize that among infants 0-6 months of age, the incidence of microbiologically-confirmed viral ARI will be significantly lower in infants whose mothers received high-dose prenatal/postpartum vitamin D supplements versus placebo. Secondary outcomes include incidence of ARI associated with specific pathogens (influenza A or B, RSV), clinical ARI, and density of pneumococcal carriage. DISCUSSION: If shown to reduce the risk of viral ARI in infancy, integration of maternal prenatal/postpartum vitamin D supplementation into antenatal care programs in South Asia may be a feasible primary preventive strategy to reduce the burden of ARI-associated morbidity and mortality in young infants. TRIAL REGISTRATION: NCT02388516 , registered March 9, 2015.

Effects of Maternal Vitamin D Supplementation During Pregnancy and Lactation on Infant Acute Respiratory Infections: Follow-up of a Randomized Trial in Bangladesh.

BACKGROUND: We examined the effect of maternal vitamin D supplementation during pregnancy and lactation on risk of acute respiratory infection (ARI) in infants up to 6 months of age in Bangladesh. METHODS: This study was nested in a randomized, double-blind, placebo-controlled, 5-arm dose-ranging trial of prenatal and postpartum vitamin D supplementation. One group of women received 0 IU vitamin D per week during pregnancy and for 26 weeks post delivery ("placebo" group), one group received high-dose prenatal vitamin D supplementation of 28 000 IU per week and 26 weeks post delivery, and there were 3 additional dose-ranging groups receiving vitamin D supplementation during pregnancy only (4200, 16 800, and 28 000 IU per week, respectively). Episodes of ARI were identified by active and passive surveillance. The primary outcome was microbiologically confirmed ARI, and the primary analysis compared the high-dose prenatal plus postpartum vitamin D vs placebo groups. RESULTS: In total, 1174 mother-infant pairs were included. Among infants born to mothers in the placebo group, 98% had a venous umbilical cord 25(OH)D level below 30 nmol/L compared with none in the high-dose prenatal plus postdelivery vitamin D group. Incidence of microbiologically confirmed ARI in the high-dose prenatal plus postpartum vitamin D (1.21 episodes per 6 person-months; N = 235) and placebo groups (1.07 episodes per 6 person-months; N = 234) was not significantly different (hazard ratio of 1.12 [95% confidence intervals: 0.90-1.40]). There were no differences in the incidence of microbiologically confirmed or clinical ARI, upper, lower, or hospitalized lower respiratory tract infection between high-dose prenatal plus postpartum vitamin D and placebo groups. CONCLUSIONS: Despite a high prevalence of maternal baseline vitamin D deficiency and significant effects of maternal vitamin D supplementation on infant vitamin D status, the intervention did not reduce the risk of microbiologically confirmed ARI in infants up to 6 months of age.