Petra  Wark

Dr. Petra Wark


Research Focus & Metrics

Academic Career Length

17Years (2010-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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27 May 2015 in Nutrients
Verified
Journal Article
Open access
PDF file
MCMichelle Carter
Michelle Carter
SASalwa Albar
Salwa Albar
MMMichelle Morris
Michelle Morris
UMUmme Z. Mulla
Umme Z. Mulla
NHNeil Hancock
Neil Hancock
JCJanet Cade
Janet Cade
Assessment of diet in large epidemiological studies can be costly and time consuming. An automated dietary assessment system could potentially reduce researcher burden by automatically coding food records. myfood24 (Measure Your Food on One Day) an online 24-h dietary assessment tool (with the flexibility to be used for multiple 24 h-dietary recalls or as a food diary), has been developed for use in the UK population. Development of myfood24 was a multi-stage process. Focus groups conducted with three age groups, adolescents (11–18 years) (n = 28), adults (19–64 years) (n = 24) and older adults (≥65 years) (n = 5) informed the development of the tool, and usability testing was conducted with beta (adolescents n = 14, adults n = 8, older adults n = 1) and live (adolescents n = 70, adults n = 20, older adults n = 4) versions. Median system usability scale (SUS) scores (measured on a scale of 0–100) in adolescents and adults were marginal for the beta version (adolescents median SUS = 66, interquartile range (IQR) = 20; adults median SUS = 68, IQR = 40) and good for the live version (adolescents median SUS = 73, IQR = 22; adults median SUS = 80, IQR = 25). Myfood24 is the first online 24-h dietary recall tool for use with different age groups in the UK. Usability testing indicates that myfood24 is suitable for use in UK adolescents and adults.

7 May 2015 in BMC Medicine
Verified
Journal Article
Open access
PDF file
DRDora Romaguera
Dora Romaguera
HWHeather Ward
Heather Ward
PPetra Wark
Petra Wark
AVAnne-Claire Vergnaud
Anne-Claire Vergnaud
PPPetra H Peeters
Petra H Peeters
TNTeresa Norat
Teresa Norat
Cancer survivors are advised to follow lifestyle recommendations on diet, physical activity, and body fatness proposed by the World Cancer Research Fund/American Institute of Cancer Research (WCRF/AICR) for cancer prevention. Previous studies have demonstrated that higher concordance with these recommendations measured using an index score (the WCRF/AICR score) was associated with lower cancer incidence and mortality. The aim of this study was to evaluate the association between pre-diagnostic concordance with WCRF/AICR recommendations and mortality in colorectal cancer (CRC) patients. The association between the WCRF/AICR score (score range 0–6 in men and 0–7 in women; higher scores indicate greater concordance) assessed on average 6.4 years before diagnosis and CRC-specific (n = 872) and overall mortality (n = 1,113) was prospectively examined among 3,292 participants diagnosed with CRC in the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort (mean follow-up time after diagnosis 4.2 years). Multivariable Cox proportional hazard models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for mortality. The HRs (95% CIs) for CRC-specific mortality among participants in the second (score range in men/women: 2.25–2.75/3.25–3.75), third (3–3.75/4–4.75), and fourth (4–6/5–7) categories of the score were 0.87 (0.72–1.06), 0.74 (0.61–0.90), and 0.70 (0.56–0.89), respectively (P for trend <0.0001), compared to participants with the lowest concordance with the recommendations (category 1 of the score: 0–2/0–3). Similar HRs for overall mortality were observed (P for trend 0.004). Meeting the recommendations on body fatness and plant food consumption were associated with improved survival among CRC cases in mutually adjusted models. Greater concordance with the WCRF/AICR recommendations on diet, physical activity, and body fatness prior to CRC diagnosis is associated with improved survival among CRC patients.

1 September 2012 in The American Journal of Clinical Nutrition
Verified
Journal Article
Closed access
PDF file
PPetra Wark
Petra Wark
RLRosa Lau
Rosa Lau
TNTeresa Norat
Teresa Norat
EKEllen Kampman
Ellen Kampman
Background: Dietary magnesium might be related to colorectal tumor risk through the pivotal roles of magnesium in cellular metabolism, insulin resistance, and systemic inflammation.

30 October 2015 in BMC Medicine
Verified
Journal Article
Open access
PDF file
MMMelissa A. Merritt
Melissa A. Merritt
ERElio Riboli
Elio Riboli
NMNeil Murphy
Neil Murphy
MKMai Kadi
Mai Kadi
ATAnne Marie Tjønneland
Anne Marie Tjønneland
MGMarc Gunter
Marc Gunter
Reproductive events are associated with important physiologic changes, yet little is known about how reproductive factors influence long-term health in women. Our objective was to assess the relation of reproductive characteristics with all-cause and cause-specific mortality risk. The analysis was performed within the European Investigation into Cancer and Nutrition prospective cohort study, which enrolled >500,000 women and men from 1992 to 2000, who were residing in a given town/geographic area in 10 European countries. The current analysis included 322,972 eligible women aged 25–70 years with 99 % complete follow-up for vital status. We assessed reproductive characteristics reported at the study baseline including parity, age at the first birth, breastfeeding, infertility, oral contraceptive use, age at menarche and menopause, total ovulatory years, and history of oophorectomy/hysterectomy. Hazard ratios (HRs) and 95 % confidence intervals (CIs) for mortality were determined using Cox proportional hazards regression models adjusted for menopausal status, body mass index, physical activity, education level, and smoking status/intensity and duration. During a mean follow-up of 12.9 years, 14,383 deaths occurred. The HR (95 % CI) for risk of all-cause mortality was lower in parous versus nulliparous women (0.80; 0.76–0.84), in women who had ever versus never breastfed (0.92; 0.87–0.97), in ever versus never users of oral contraceptives (among non-smokers; 0.90; 0.86–0.95), and in women reporting a later age at menarche (≥15 years versus <12; 0.90; 0.85–0.96; P for trend = 0.038). Childbirth, breastfeeding, oral contraceptive use, and a later age at menarche were associated with better health outcomes. These findings may contribute to the development of improved strategies to promote better long-term health in women.

5 August 2016 in Nutrients
Verified
Journal Article
Open access
PDF file
MCMichelle Carter
Michelle Carter
NHNeil Hancock
Neil Hancock
SASalwa Albar
Salwa Albar
HBHelen Brown
Helen Brown
DGDarren Greenwood
Darren Greenwood
JCJanet Cade
Janet Cade
The current UK food composition tables are limited, containing ~3300 mostly generic food and drink items. To reflect the wide range of food products available to British consumers and to potentially improve accuracy of dietary assessment, a large UK specific electronic food composition database (FCDB) has been developed. A mapping exercise has been conducted that matched micronutrient data from generic food codes to “Back of Pack” data from branded food products using a semi-automated process. After cleaning and processing, version 1.0 of the new FCDB contains 40,274 generic and branded items with associated 120 macronutrient and micronutrient data and 5669 items with portion images. Over 50% of food and drink items were individually mapped to within 10% agreement with the generic food item for energy. Several quality checking procedures were applied after mapping including; identifying foods above and below the expected range for a particular nutrient within that food group and cross-checking the mapping of items such as concentrated and raw/dried products. The new electronic FCDB has substantially increased the size of the current, publically available, UK food tables. The FCDB has been incorporated into myfood24, a new fully automated online dietary assessment tool and, a smartphone application for weight loss.

30 July 2016 in BMC Public Health
Verified
Journal Article
Open access
PDF file
RGRama Greenfield
Rama Greenfield
EBEllen Busink
Ellen Busink
CWCybele P. Wong
Cybele P. Wong
EREva Riboli-Sasco
Eva Riboli-Sasco
GGGeva Greenfield
Geva Greenfield
PPetra Wark
Petra Wark
Professional truck drivers, as other shift workers, have been identified as a high-risk group for various health conditions including cardiovascular disease, obesity, diabetes, sleep apnoea and stress. Mobile health technologies can potentially improve the health and wellbeing of people with a sedentary lifestyle such as truck drivers. Yet, only a few studies on health promotion interventions related to mobile health technologies for truck drivers have been conducted. We aimed to explore professional truck drivers’ views on health promotion delivered via mobile health technologies such as wearable devices. We conducted a phenomenological qualitative study, consisting of four semi-structured focus groups with 34 full-time professional truck drivers in the UK. The focus groups were audio-taped, transcribed verbatim and analysed using thematic content analysis. We discussed drivers’ perceptions of their health, lifestyle and work environment, and their past experience and expectations from mobile health technologies. The participants viewed their lifestyle as unhealthy and were aware of possible consequences. They expressed the need and wish to change their lifestyle, yet perceived it as an inherent, unavoidable outcome of their occupation. Current health improvement initiatives were not always aligned with their working conditions. The participants were generally willing to use mobile health technologies such as wearable devices, as a preventive measure to avoid prospect morbidity, particularly cardiovascular diseases. They were ambivalent about privacy and the risk of their employer’s monitoring their clinical data. Wearable devices may offer new possibilities for improving the health and wellbeing of truck drivers. Drivers were aware of their unhealthy lifestyle. They were interested in changing their lifestyle and health. Drivers raised concerns regarding being continuously monitored by their employer. Health improvement initiatives should be aligned with the unique working conditions of truck drivers. Future research is needed to examine the impact of wearable devices on improving the health and wellbeing of professional drivers.