Ridvan Firestone

Sleep duration and quality in healthy nulliparous and multiparous women across pregnancy and post-partum.

Background:  Longitudinal studies of sleep during normal pregnancy and post‐partum are rare, and interpretation of the findings is often hampered by methodological issues. Consequentially, there is still limited information on what constitutes normal sleep quality and quantity across pregnancy and early post‐partum, for both nulliparous and multiparous women.

Association between Recruitment Methods and Attrition in Internet-Based Studies

Internet-based systems for epidemiological studies have advantages over traditional approaches as they can potentially recruit and monitor a wider range of individuals in a relatively inexpensive fashion. We studied the association between communication strategies used for recruitment (offline, online, face-to-face) and follow-up participation in nine Internet-based cohorts: the Influenzanet network of platforms for influenza surveillance which includes seven cohorts in seven different European countries, the Italian birth cohort Ninfea and the New Zealand birth cohort ELF. Follow-up participation varied from 43% to 89% depending on the cohort. Although there were heterogeneities among studies, participants who became aware of the study through an online communication campaign compared with those through traditional offline media seemed to have a lower follow-up participation in 8 out of 9 cohorts. There were no clear differences in participation between participants enrolled face-to-face and those enrolled through other offline strategies. An Internet-based campaign for Internet-based epidemiological studies seems to be less effective than an offline one in enrolling volunteers who keep participating in follow-up questionnaires. This suggests that even for Internet-based epidemiological studies an offline enrollment campaign would be helpful in order to achieve a higher participation proportion and limit the cohort attrition.

Cigarette Smoking and Risk of Breast Cancer in a New Zealand Multi-Ethnic Case-Control Study

Background The association between breast cancer and tobacco smoke is currently unclear. The aim of this study was to assess the effect of smoking behaviours on the risk of breast cancer among three ethnic groups of New Zealand women. Methods A population-based case-control study was conducted including breast cancer cases registered on the New Zealand Cancer Registry between 2005 and 2007. Controls were matched by ethnicity and 5-year age-group. Logistic regression was used to estimate the association between breast cancer and smoking at different time points across the lifecourse, for each ethnic group. Estimated odds ratios (OR) were adjusted for established risk factors. Results The study comprised 1,799 cases (302 Māori, 70 Pacific, 1,427 non-Māori/non-Pacific) and 2,540 controls (746 Māori, 191 Pacific, 1,603 non-Māori/non-Pacific). There was no clear association between smoking and breast cancer for non-Māori/non-Pacific women, although non-Māori/non-Pacific ex-smokers had statistically significant increased risk of breast cancer when smoking duration was 20 years or more, and this remained significant in the fully adjusted model (OR 1.31, 95% CI 1.03 to 1.66). Māori showed more consistent increased risk of breast cancer with increasing duration among current smokers (<20 years OR 1.61, 95% CI 0.55 to 4.74; 20+ years OR 2.03, 95% CI 1.29 to 3.22). There was a clear pattern of shorter duration since smoking cessation being associated with increased likelihood of breast cancer, and this was apparent for all ethnic groups. Conclusion There was no clear pattern for cigarette smoking and breast cancer incidence in non-Māori/non-Pacific women, but increased risks were observed for Māori and Pacific women. These findings suggest that lowering the prevalence of smoking, especially among Māori and Pacific women, could be important for reducing breast cancer incidence.

Obstructive sleep apnoea among professional taxi drivers: A pilot study

PURPOSE This study aimed to describe the distribution of risk factors for obstructive sleep apnoea syndrome (OSAS) among taxi drivers, and to investigate differences by ethnicity in OSAS symptoms among drivers. METHODS A two-page postal questionnaire was completed by 241 professional taxi drivers from Wellington, New Zealand. Obstructive sleep apnoea syndrome was defined as having an estimated 15 or more respiratory disturbances, per hour of sleep (Respiratory Disturbance Index (RDI)> or =15) and self-reported daytime sleepiness. RESULTS Pacific and Māori taxi drivers were more likely to have symptoms and risk factors for OSAS, compared to non-Māori non-Pacific drivers. In particular, Pacific drivers had a significantly increased pre-test probability of having moderate-severe OSA (RDI> or =15). CONCLUSIONS Some professional taxi drivers are at increased risk for moderate-severe OSAS, especially Pacific and Māori taxi drivers. Untreated OSAS increases motor vehicle crash risk, so these findings have implications for the health and safety of drivers and their passengers. They suggest a need for more comprehensive research to guide policy on medical examinations required for licensing professional drivers as fit to drive.

Healthy lifestyle and risk of breast cancer for indigenous and non-indigenous women in New Zealand: a case control study

BackgroundThe reasons for the increasing breast cancer incidence in indigenous Māori compared to non-Māori New Zealand women are unknown. The aim of this study was to assess the association of an index of combined healthy lifestyle behaviours with the risk of breast cancer in Māori and non-Māori women.MethodsA population-based case–control study was conducted, including breast cancer cases registered in New Zealand from 2005–2007. Controls were matched by ethnicity and 5-year age bands. A healthy lifestyle index score (HLIS) was generated for 1093 cases and 2118 controls, based on public health and cancer prevention recommendations. The HLIS was constructed from eleven factors (limiting red meat, cream, and cheese; consuming more white meat, fish, fruit and vegetables; lower alcohol consumption; not smoking; higher exercise levels; lower body mass index; and longer cumulative duration of breastfeeding). Equal weight was given to each factor. Logistic regression was used to estimate the associations between breast cancer and the HLIS for each ethnic group stratified by menopausal status.ResultsAmong Māori, the mean HLIS was 5.00 (range 1–9); among non-Māori the mean was 5.43 (range 1.5-10.5). There was little evidence of an association between the HLIS and breast cancer for non-Māori women. Among postmenopausal Māori, those in the top HLIS tertile had a significantly lower odds of breast cancer (Odds Ratio 0.47, 95% confidence interval 0.23-0.94) compared to those in the bottom tertile.ConclusionThese findings suggest that healthy lifestyle recommendations could be important for reducing breast cancer risk in postmenopausal Māori women.

Ethnic differences in risk factors for obesity in New Zealand infants

Background In New Zealand, the burden of childhood obesity is greatest in Māori and Pacific children. Methods In 687 infants from an internet-based birth cohort in New Zealand, we investigated ethnic differences in early life risk factors for later obesity, the degree to which these were explained by sociodemographic factors, and the extent to which ethnic differences in weight at age 3 months were explained by measured risk factors. Results The risk of having an obese mother was double in Māori and Pacific infants compared with NZ European infants (prevalence 24% and 14%, respectively; OR 2.23, 95% CI 1.23 to 4.04). Māori and Pacific infants had higher weights in the first week of life and at 3 months (mean difference 0.19 kg, 95% CI 0.01 to 0.38), and their mothers had higher scores on a ‘snacks’ dietary pattern and lower scores on ‘healthy’ and ‘sweet’ dietary patterns. These inequalities were not explained by maternal education, maternal age or area-based deprivation. No ethnic differences were observed for maternal pre-pregnancy physical activity, hypertension or diabetes in pregnancy, exclusive breastfeeding or early introduction of solid foods. Ethnic inequalities in infant weight at 3 months were not explained by sociodemographic variables, maternal pre-pregnancy body mass index or dietary pattern scores or by other measured risk factors. Conclusions This study shows excess prevalence of early life risk factors for obesity in Māori and Pacific infants in New Zealand and suggests an urgent need for early interventions for these groups.

Predictors and risks of body fat profiles in young New Zealand European, Māori and Pacific women: study protocol for the women's EXPLORE study

BackgroundBody mass index (BMI) (kg/m2) is used internationally to assess body mass or adiposity. However, BMI does not discriminate body fat content or distribution and may vary among ethnicities. Many women with normal BMI are considered healthy, but may have an unidentified “hidden fat” profile associated with higher metabolic disease risk. If only BMI is used to indicate healthy body size, it may fail to predict underlying risks of diseases of lifestyle among population subgroups with normal BMI and different adiposity levels or distributions. Higher body fat levels are often attributed to excessive dietary intake and/or inadequate physical activity. These environmental influences regulate genes and proteins that alter energy expenditure/storage. Micro ribonucleic acid (miRNAs) can influence these genes and proteins, are sensitive to diet and exercise and may influence the varied metabolic responses observed between individuals. The study aims are to investigate associations between different body fat profiles and metabolic disease risk; dietary and physical activity patterns as predictors of body fat profiles; and whether these risk factors are associated with the expression of microRNAs related to energy expenditure or fat storage in young New Zealand women. Given the rising prevalence of obesity globally, this research will address a unique gap of knowledge in obesity research.Methods/DesignA cross-sectional design to investigate 675 NZ European, Māori, and Pacific women aged 16–45 years. Women are classified into three main body fat profiles (n = 225 per ethnicity; n = 75 per body fat profile): 1) normal BMI, normal body fat percentage (BF%); 2) normal BMI, high BF%; 3) high BMI, high BF%. Regional body composition, biomarkers of metabolic disease risk (i.e. fasting insulin, glucose, HbA1c, lipids), inflammation (i.e. IL-6, TNF-alpha, hs-CRP), associations between lifestyle factors (i.e. dietary intake, physical activity, taste perceptions) and microRNA expression will be investigated.DiscussionThis research targets post-menarcheal, premenopausal women, potentially exhibiting lifestyle behaviours resulting in excess body fat affecting metabolic health. These behaviours may be characterised by specific patterns of microRNA expression that will be explored in terms of tailored solutions specific to body fat profile groups and ethnicities.Trial registrationACTRN12613000714785

Internet-Based Birth-Cohort Studies: Is This the Future for Epidemiology?

Background International collaborative cohorts the NINFEA and the ELF studies are mother-child cohorts that use the internet for recruitment and follow-up of their members. The cohorts investigated the association of early life exposures and a wide range of non-communicable diseases. Objective The objective is to report the research methodology, with emphasis on the advantages and limitations offered by an Internet-based design. These studies were conducted in Turin, Italy and Wellington, New Zealand. Methods The cohorts utilized various online/offline methods to recruit participants. Pregnant women who became aware volunteered, completed an online questionnaire, thus obtaining baseline information. Results The NINFEA study has recruited 7003 pregnant women, while the ELF study has recruited 2197 women. The cohorts targeted the whole country, utilizing a range of support processes to reduce the attrition rate of the participants. For the NINFEA and ELF cohorts, online participants were predominantly older (35% and 28.9%, respectively), highly educated (55.6% and 84.9%, respectively), and were in their final trimester of pregnancy (48.5% and 53.6%, respectively). Conclusions Internet-based cohort epidemiological studies are feasible, however, it is clear that participants are self-selective samples, as is the case for many birth cohorts. Internet-based cohort studies are potentially cost-effective and novel methodology for conducting long-term epidemiology research. However, from our experience, participants tend to be self-selective. In marked time, if the cohorts are to form part of a larger research program they require further use and exploration to address biases and overcome limitations.

Co-design of mHealth Delivered Interventions: A Systematic Review to Assess Key Methods and Processes

Most mobile health (mHealth) programmes are designed with minimal input from target end users and are not truly personalised or adaptive to their specific and evolving needs. This review describes the methods and processes used in the co-design of mHealth interventions. Nine relevant studies of varying design were identified following searches of six academic databases. All employed co-design or participatory methods for the development of a health intervention delivered via a mobile device, with three focusing on health behaviour change (one on nutrition) and six on management of a health condition. Overall, six key phases of design and 17 different methods were used. Sufficiency of reporting was poor, and no study undertook a robust assessment of efficacy; these factors should be a focus for future studies. An opportunity exists to use co-design methods to develop acceptable and feasible mHealth interventions, especially to support improved nutrition and for minority and indigenous groups.

Ethnic differences in disease presentation of uterine cancer in New Zealand women

Objectives Little is known about the ethnic differences in disease presentation of uterine cancer in New Zealand women. The objectives of this study were two-fold: (1) to estimate the incidence and mortality of uterine cancer among women in New Zealand and (2) to examine the association of ethnicity and socioeconomic status with tumour stage and grade, at presentation of uterine cancer. Methods Retrospective survey of cancer cases identified from the New Zealand Cancer Registry. The authors analysed all 3203 uterine cancer cases registered with the New Zealand Cancer Registry during the period 1 January 1997 to 31 December 2006. Ethnic groups were defined based on the self-identified ethnicity recorded on the cancer registry: Ma–ori, Pacific and non-M–aori non-Pacific women. Socioeconomic status was categorised as quintiles of the New Zealand Deprivation Index 2006. The mortality to incidence ratio was used as a measure of prognosis. Logistic regression was used to estimate age, ethnic and deprivation adjusted odds ratios (ORs) and 95% confidence intervals (CIs). Results Pacific and M–aori women have higher incidence (32.4 and 17.7 per 100 000 women, respectively) and mortality rates of uterine cancer (12.1 and 7.4 per 100 000 women, respectively). Women in the most deprived areas are more likely to present with an advanced stage of uterine cancer (OR 1.64, 95% CI 1.09–2.48). M–aori and Pacific women are less likely to present with well-differentiated tumours (OR 0.69, 95% CI 0.52–0.92 and OR 0.72, 95% CI 0.52–0.99, respectively). Conclusions M–aori and Pacific women, and those from lower socioeconomic areas, are more likely to present with advanced uterine cancer.