Philippos Orfanos - Academia.edu (original) (raw)

Papers by Philippos Orfanos

Epidemiology, Biostatistics, and Public Health

Background: According to a large prospective cohort study (with baseline examination in the 1990... more Background: According to a large prospective cohort study (with baseline examination in the 1990s) and smaller studies that followed, the population in Greece has been gradually deprived of the favorable morbidity and mortality indices recorded in the 1960s. The HYDRIA survey conducted in 2013-14 is the first nationally representative survey, which collected data related to the health and nutrition of the population in Greece. Methods: The survey sample consists of 4011 males (47%) and females aged 18 years and over. Data collection included interviewer-administered questionnaires on personal characteristics, lifestyle choices, dietary habits and medical history; measurements of somatometry and blood pressure; and, blood drawing. Weighting factors were applied to ensure national representativeness of results. Results: Three out of five adults in Greece reported suffering of a chronic disease, with diabetes mellitus and chronic depression being the more frequent ones among older ind...

Vaccines

Sports have been majorly impacted by the COVID-19 pandemic. After the lockdown period, vaccinatio... more Sports have been majorly impacted by the COVID-19 pandemic. After the lockdown period, vaccination and protocols were implemented to return to normality. We aimed to assess the attitudes and practices related to COVID-19 vaccination among athletes, and to record adverse effects of vaccination, if any. A questionnaire was distributed to 1012 male and female athletes, 15+ years old, within the region of Athens. Vaccination coverage with at least one dose was 93.5%, whereas 53.9% were fully vaccinated. More than half of the participants were infected with SARS-CoV-2 at the time of the study. More than 90% of the participants, considered the vaccines as safe, effective and important for public health. Concern about potential side-effects was raised especially by women athletes (59.1% of women compared to 42.2% of men, p < 0.001). The main reasons for avoiding vaccination were fear of vaccine safety, concern about the short time period for vaccine development and testing and doubt of ...

Model-based survival functions for men and women in EPIC (coloured lines) and a random sample of ... more Model-based survival functions for men and women in EPIC (coloured lines) and a random sample of Kaplan–Meier estimates of the survival function evaluated at failure times (grey dots). Survival to age 70 years in the EU in general was estimated to be 0.89 for women and 0.80 for men (using mortality rates from 2006–2010 obtained from http://ec.europa.eu/eurostat ). (TIFF 402 kb)

Model -based survival functions for each country in EPIC, by sex and smoking status. (TIFF 824 kb)

Population attributable fractions of deaths prior to age 65 years given the distribution of covar... more Population attributable fractions of deaths prior to age 65 years given the distribution of covariates in the EPIC cohort, using waist-to-hip ratio to assess for obesity. (PDF 75 kb)

Attributable fractions of deaths prior to age 70 years given the distribution of covariates in th... more Attributable fractions of deaths prior to age 70 years given the distribution of covariates in the EPIC cohort, using body mass index to assess overweight and obesity. (PDF 49 kb)

Stratification of meta-analyses and reassessment of heterogeneity for the association of smoking ... more Stratification of meta-analyses and reassessment of heterogeneity for the association of smoking status with total cancer incidence and mortality according to the general cohort characteristics (Table S3). (DOC 82 kb)

Stratification of meta-analyses and reassessment of heterogeneity for the association of smoking ... more Stratification of meta-analyses and reassessment of heterogeneity for the association of smoking status with lung cancer incidence and mortality according to the general cohort characteristics (Table S4). (DOC 79 kb)

Children, 2022

Excessive body weight during adolescence represents a significant public health problem worldwide... more Excessive body weight during adolescence represents a significant public health problem worldwide. Identifying factors associated with its development is crucial. We estimated the prevalence of overweight and obesity in a representative sample of 11, 13 and, 15-year-olds living in Greece and explored the association with diet-related behaviours and habits. Self-reported data on weight, height, diet-related behaviours and habits were used from 3816 students (1898 boys, 1918 girls) participants in the Greek arm of the international Health Behaviour in School-Aged Children (HBSC) study during 2018. Overweight and obesity were defined using the 2007 WHO growth charts classification. Prevalence of overweight was 19.4% in the total sample, 24.1% for boys and 14.7% for girls, and prevalence of obesity was 5.3% in the total sample, 7.3% for boys and 3.4% for girls, respectively. In the total sample, overweight (including obesity) was positively associated with male gender, low family afflue...

We are indebted to the participants in the NIH-AARP Diet and Health Study for their outstanding c... more We are indebted to the participants in the NIH-AARP Diet and Health Study for their outstanding cooperation. We also thank Sigurd Hermansen and Kerry Grace Morrissey from Westat for study outcomes ascertainment and management and Leslie Carroll at Information Management Services for data support and analysis. Conflict of interest: The authors declare that they have no conflict of interest. Ethical standard: All of the cohorts obtained ethical approval and written informed consent was obtained from all participants.

Nurse Education in Practice, 2021

AIM To investigate medical and nursing students' education on hand hygiene, their attitude on... more AIM To investigate medical and nursing students' education on hand hygiene, their attitude on hand hygiene education and how this education influences their hand hygiene knowledge and practices. BACKGROUND Hospital-acquired infections are associated with prolonged hospitalisation and mortality. The most effective measure for their control is healthcare workers' hand hygiene compliance. Since medical and nursing students constitute the future healthcare workers, our study focuses on them. DESIGN Cross-sectional study METHODS: This study was conducted during the academic year 2016-2017, using a modified World Health Organisation questionnaire. Our sample consisted of 132 medical and 111 nursing students from National and Kapodistrian University of Athens, Greece. In data analysis, the Mann-Whitney and Fisher's exact tests were applied to compare differences in continuous variables and proportions in categorical variables, respectively. Knowledge and practices overall scores were calculated per student group. Multiple linear regression analyses were performed to assess the influence of potential confounders on these scores. RESULTS We found that 73.1% of medical and 98.2% of nursing students had received relevant education, which was reported as "only theoretical" by 77.4% of the former and as "hands-on and theoretical" by 88.1% of the latter group. Besides the risk of infection, knowledge acquired in lectures and trainer's behaviour were also considered very influential factors shaping hand hygiene attitude in both groups. Overall, medical students reported better hand hygiene practices than nursing ones (69.9% and 59.7%, respectively; p < 0.001). The opposite finding was observed regarding their overall knowledge on hand hygiene (57.2% of medical versus 60.4% of nursing students, p = 0.04). The majority of students (86.6% of all participants; p < 0.001) supported the inclusion of compulsory hand hygiene education in their curriculum. Compulsory education and seminars were assessed as the most effective measures to increase hand hygiene compliance (71.4% of all students). CONCLUSION In our study, medical students scored better in practices questions than nursing students; this did not apply for the knowledge score. The majority of students supported the inclusion of compulsory education on hand hygiene principles in their Departments' curricula, highlighting compulsory education and seminars as the most effective measures to increase compliance with hand hygiene.

Cancer epidemiology, biomarkers & prevention : a publication of the American Association for Cancer Research, cosponsored by the American Society of Preventive Oncology, Jan 28, 2016

It is unknown if dietary recommendations for cancer prevention are applicable to the elderly. We ... more It is unknown if dietary recommendations for cancer prevention are applicable to the elderly. We analyzed WCRF/AICR recommendations in cohorts of European and US adults aged 60 years and above. Individual participant data meta-analysis including 362,114 participants (43% women), from seven prospective cohort studies, free from cancer at enrollment. The WCRF/AICR diet score was based on: 1) energy-dense foods and sugary drinks, 2) plant foods, 3) red and processed meat 4) alcoholic drinks. Cox proportional hazards regression was used to examine the association between the diet score and cancer risks. Adjusted, cohort-specific hazard ratios (HR) were pooled using random-effects meta-analysis. Risk Advancement Periods (RAP) were calculated to quantify the time period by which the risk of cancer was postponed among those adhering to the recommendations. After a median follow-up of 11 to 15 years across cohorts, 69,708 cancer cases were identified. Each one-point increase in the WCRF/AIC...

Breast Cancer Research, 2015

Introduction: Specific coffee subtypes and tea may impact risk of pre-and post-menopausal breast ... more Introduction: Specific coffee subtypes and tea may impact risk of pre-and post-menopausal breast cancer differently. We investigated the association between coffee (total, caffeinated, decaffeinated) and tea intake and risk of breast cancer. Methods: A total of 335,060 women participating in the European Prospective Investigation into Nutrition and Cancer (EPIC) Study, completed a dietary questionnaire from 1992 to 2000, and were followed-up until 2010 for incidence of breast cancer. Hazard ratios (HR) of breast cancer by country-specific, as well as cohort-wide categories of beverage intake were estimated. Results: During an average follow-up of 11 years, 1064 premenopausal, and 9134 postmenopausal breast cancers were diagnosed. Caffeinated coffee intake was associated with lower risk of postmenopausal breast cancer: adjusted HR = 0.90, 95% confidence interval (CI): 0.82 to 0.98, for high versus low consumption; P trend = 0.029. While there was no significant effect modification by hormone receptor status (P = 0.711), linear trend for lower risk of breast cancer with increasing caffeinated coffee intake was clearest for estrogen and progesterone receptor negative (ER-PR-), postmenopausal breast cancer (P = 0.008). For every 100 ml increase in caffeinated coffee intake, the risk of ER-PR-breast cancer was lower by 4% (adjusted HR: 0.96, 95% CI: 0.93 to 1.00). Non-consumers of decaffeinated coffee had lower risk of postmenopausal breast cancer (adjusted HR = 0.89; 95% CI: 0.80 to 0.99) compared to low consumers, without evidence of doseresponse relationship (P trend = 0.128). Exclusive decaffeinated coffee consumption was not related to postmenopausal breast cancer risk, compared to any decaffeinated-low caffeinated intake (adjusted HR = 0.97; 95% CI: 0.82 to 1.14), or to no intake of any coffee (HR: 0.96; 95%: 0.82 to 1.14). Caffeinated and decaffeinated coffee were not associated with premenopausal breast cancer. Tea intake was neither associated with pre-nor post-menopausal breast cancer.

International Journal of Cancer, 2014

Long-term weight gain (i.e., weight gain since age 20) has been related to higher risk of postmen... more Long-term weight gain (i.e., weight gain since age 20) has been related to higher risk of postmenopausal breast cancer, but a lower risk of premenopausal breast cancer. The effect of weight change in middle adulthood is unclear. We investigated the association between weight change in middle adulthood (i.e., women aged 40-50 years) and the risk of breast cancer before and after the age of 50. We included female participants of the European Prospective Investigation into Cancer and Nutrition cohort, with information on anthropometric measures at recruitment and after a median follow-up of 4.3 years. Annual weight change was categorized using quintiles taking quintile 2 and 3 as the reference category (-0.44 to 0.36 kg/year). Multivariable Cox proportional hazards regression analysis was used to examine the association. 205,723 women were included and 4,663 incident breast cancer cases were diagnosed during a median follow-up of 7.5 years (from second weight assessment onward). High weight gain (Q5: 0.83-4.98 kg/year) was related to a slightly, but significantly higher breast cancer risk (HRQ5_versus_Q2/3 : 1.09, 95% CI: 1.01-1.18). The association was more pronounced for breast cancer diagnosed before or at age 50 (HRQ5_versus_Q2/3 : 1.37, 95% CI: 1.02-1.85). Weight loss was not associated with breast cancer risk. There was no evidence for heterogeneity by hormone receptor status. In conclusion, high weight gain in middle adulthood increases the risk of breast cancer. The association seems to be more pronounced for breast cancer diagnosed before or at age 50. Our results illustrate the importance of avoiding weight gain in middle adulthood.

The American Journal of Clinical Nutrition, 2011

Background: The protective effect of physical activity (PA) on abdominal adiposity is unclear. Ob... more Background: The protective effect of physical activity (PA) on abdominal adiposity is unclear. Objective: We examined whether PA independently predicted gains in body weight and abdominal adiposity. Design: In a prospective cohort study [the EPIC (European Prospective Investigation into Cancer and Nutrition)], we followed 84,511 men and 203,987 women for 5.1 y. PA was assessed by a validated questionnaire, and individuals were categorized into 4 groups (inactive, moderately inactive, moderately active, and active). Body weight and waist circumference were measured at baseline and self-reported at follow-up. We used multilevel mixedeffects linear regression models and stratified our analyses by sex with adjustments for age, smoking status, alcohol consumption, educational level, total energy intake, duration of follow-up, baseline body weight, change in body weight, and waist circumference (when applicable). Results: PA significantly predicted a lower waist circumference (in cm) in men (b = 20.045; 95% CI: 20.057, 20.034) and in women (b = 20.035; 95% CI: 20.056, 20.015) independent of baseline body weight, baseline waist circumference, and other confounding factors. The magnitude of associations was materially unchanged after adjustment for change in body weight. PA was not significantly associated with annual weight gain (in kg) in men (b = 20.008; 95% CI: 20.02, 0.003) and women (b = 20.01; 95% CI: 20.02, 0.0006). The odds of becoming obese were reduced by 7% (P , 0.001) and 10% (P , 0.001) for a one-category difference in baseline PA in men and women, respectively. Conclusion: Our results suggest that a higher level of PA reduces abdominal adiposity independent of baseline and changes in body weight and is thus a useful strategy for preventing chronic diseases and premature deaths.

Journal of Clinical Medicine, 2021

Acute kidney injury (AKI) is one of the most common complications in critically ill patients. In ... more Acute kidney injury (AKI) is one of the most common complications in critically ill patients. In recent years, studies have focused on exploring new biomarkers for the early diagnosis and prognosis of AKI. The aim of this study was to investigate serum prognostic biomarkers (neutrophil gelatinase-associated lipocalin, NGAL, and creatinine) of AKI in critically ill patients. The study included 266 critically ill, initially nonseptic, patients admitted to a multidisciplinary ICU. Serum levels of NGAL and creatinine were measured at ICU admission. ROC curves were generated to estimate the prognostic value of the biomarkers, while a logistic regression analysis was performed to assess their association with an increased AKI risk. Patients were divided in two groups based on the development (n = 98) or not (n = 168) of AKI during their ICU stay. Serum NGAL levels at ICU admission were significantly higher in those who subsequently developed AKI compared to those who did not (p < 0.000...

Nutrients

Prevalence of diet-related behaviors (i.e., breakfast consumption, eating with the family) and th... more Prevalence of diet-related behaviors (i.e., breakfast consumption, eating with the family) and their association with a 17-point diet quality score, constructed on the basis of reported frequency (in days/week) of vegetable, fruit, sweets and sugar-sweetened beverages consumption, was investigated among 3525 adolescents (51.5% girls) aged 11, 13 and 15 years, who were participants in the Greek arm of the international Health Behaviour in School-Aged Children (HBSC) cross-sectional study, during 2018. Almost one-third (32.9%) of the sample had breakfast ≤1 day/weekdays, 20.2% rarely ate with the family, 26.1% had a meal while watching TV ≥5 days/week, 31.7% had a snack in front of a screen ≥5 days/week and 24.1% ate in fast-food restaurants at least once/week. Multivariable ordinal logistic regression revealed that eating breakfast ≤1 day/weekdays compared to 4–5 days/weekdays (Odds ratio (OR): 1.56, 95% con-fidence interval (CI): 1.34–1.82), eating rarely with the family compared to...

Breast Cancer Research

Background: Few published breast cancer (BC) risk prediction models consider the heterogeneity of... more Background: Few published breast cancer (BC) risk prediction models consider the heterogeneity of predictor variables between estrogen-receptor positive (ER+) and negative (ER-) tumors. Using data from two large cohorts, we examined whether modeling this heterogeneity could improve prediction. Methods: We built two models, for ER+ (Model ER+) and ER-tumors (Model ER-), respectively, in 281,330 women (51% postmenopausal at recruitment) from the European Prospective Investigation into Cancer and Nutrition cohort. Discrimination (C-statistic) and calibration (the agreement between predicted and observed tumor risks) were assessed both internally and externally in 82,319 postmenopausal women from the Women's Health Initiative study. We performed decision curve analysis to compare Model ER+ and the Gail model (Model Gail) regarding their applicability in risk assessment for chemoprevention. Results: Parity, number of full-term pregnancies, age at first full-term pregnancy and body height were only associated with ER+ tumors. Menopausal status, age at menarche and at menopause, hormone replacement therapy, postmenopausal body mass index, and alcohol intake were homogeneously associated with ER+ and ER-tumors. Internal validation yielded a C-statistic of 0.64 for Model ER+ and 0.59 for Model ER-. External validation reduced the C-statistic of Model ER+ (0.59) and Model Gail (0.57). In external evaluation of calibration, Model ER+ outperformed the Model Gail : the former led to a 9% overestimation of the risk of ER+ tumors, while the latter yielded a 22% underestimation of the overall BC risk. Compared with the treat-all strategy, Model ER+ produced equal or higher net benefits irrespective of the benefit-to-harm ratio of chemoprevention, while Model Gail did not produce higher net benefits unless the benefit-to-harm ratio was below 50. The clinical applicability, i.e. the area defined by the net benefit curve and the treat-all and treat-none strategies, was 12.7 × 10 − 6 for Model ER+ and 3.0 × 10 − 6 for Model Gail. Conclusions: Modeling heterogeneous epidemiological risk factors might yield little improvement in BC risk prediction. Nevertheless, a model specifically predictive of ER+ tumor risk could be more applicable than an omnibus model in risk assessment for chemoprevention.

Public health nutrition, Jan 17, 2018

To examine timing of eating across ten European countries. Cross-sectional analysis of the Europe... more To examine timing of eating across ten European countries. Cross-sectional analysis of the European Prospective Investigation into Cancer and Nutrition (EPIC) calibration study using standardized 24 h diet recalls collected during 1995-2000. Eleven predefined food consumption occasions were assessed during the recall interview. We present time of consumption of meals and snacks as well as the later:earlier energy intake ratio, with earlier and later intakes defined as 06.00-14.00 and 15.00-24.00 hours, respectively. Type III tests were used to examine associations of sociodemographic, lifestyle and health variables with timing of energy intake. Ten Western European countries. In total, 22 985 women and 13 035 men aged 35-74 years (n 36 020). A south-north gradient was observed for timing of eating, with later consumption of meals and snacks in Mediterranean countries compared with Central and Northern European countries. However, the energy load was reversed, with the later:earlier ...

Cancer epidemiology, biomarkers & prevention : a publication of the American Association for Cancer Research, cosponsored by the American Society of Preventive Oncology, Jan 16, 2018

Neoplastic and non-neoplastic events may raise levels of mucins, CA15.3 and CA125, and generate a... more Neoplastic and non-neoplastic events may raise levels of mucins, CA15.3 and CA125, and generate antibodies against them; but their impact on epithelial ovarian cancer (EOC) risk has not been fully defined. CA15.3, CA125, and IgG1 antibodies against them were measured in 806 women who developed EOC and 1,927 matched controls from the European Prospective Investigation of Nutrition and Cancer. Associations between epidemiologic factors and anti-mucin antibodies were evaluated using generalized linear models; EOC risks associated with anti-mucin antibodies, by themselves or in combination with respective antigens, were evaluated using conditional logistic regression. In controls, lower antibodies against both mucins were associated with current smoking; and, in postmenopausal women, higher levels with longer oral contraceptive use and later-age-at and shorter-interval-since last birth. Lower anti-CA15.3 antibodies were associated with higher body mass and, in premenopausal women, more ...