Int. J. Epidemiol. Advance Access published May 6, 2015 International Journal of Epidemiology, 2015, 1–9 doi: 10.1093/ije/dyv037 Cohort Profile
Cohort Profile
Cohort Profile: The Polish-Norwegian Study (PONS) cohort Marta Manczuk,1* Paolo Boffetta,2 Samantha Sartori,2 Dana Hashim,2 Lars J Vatten3 and Witold A Zatonski1 1
Downloaded from http://ije.oxfordjournals.org/ at Dalhousie University on May 17, 2015
Department of Cancer Epidemiology, Maria Sklodowska-Curie Memorial Cancer Center and Institute of Oncology, Warsaw, Poland, 2Icahn School of Medicine at Mount Sinai, New York, NY, USA and 3 Norwegian University of Science and Technology, Trondheim, Norway *Corresponding author. Department of Cancer Epidemiology, Maria Sklodowska-Curie Memorial Cancer Center and Institute of Oncology, 02-034 Warszawa, ul. Wawelska 15B, Poland. E-mail: [email protected]
Abstract The PONS cohort is a longitudinal observational regional study collecting information on health and health-related behaviours in the south-eastern part of Poland. The study aims at providing information on determinants of health differences between Poland and other countries in the region, especially related to premature mortality. The baseline data collection contains records for 13 172 individuals (2010–11), between 45 and 64 years of age, from the city of Kielce and surrounding rural area. All cohort members were volunteer participants and gave informed consent prior to inclusion. Data were collected on current health status, medical history and health-related behaviours with focus on preventable causes of chronic diseases, including tobacco smoking, alcohol consumption, physical activity and dietary habits. In addition to an extensive questionnaire, blood and urine samples were collected for storage. The study is expected to provide valuable evidence related to various lifestyle behaviours and health, and insight into the usefulness of population approaches for preventive interventions in Polish communities. To access data or biological material or to use the sample to recruit participants for new studies, researchers should contact the principal investigator, Witold A Zatonski at: [[email protected]].
Key Messages • Initial PONS findings provide a detailed description of the study population indicating areas that may require inter-
ventions and providing valuable information for regional health policy. • The PONS study offers a valuable data source, including biological material that can serve various research purposes
thanks to a broad consent form. • Baseline data collection revealed a high prevalence of non-communicable chronic diseases but drew also attention to
poorly controlled common conditions, such as hypertension and diabetes. C The Author 2015; all rights reserved. Published by Oxford University Press on behalf of the International Epidemiological Association V
1
2
Why was the cohort set up?
Who is in the cohort? In the first phase, between September 2010 and December 2011, PONS recruited 13 172 adults aged 45–64 years
from the general populations of two geographically distinct regions: one urban district—the city of Kielce [60 000 residents aged 45–64 years, of whom 8000 (13%) were included in the PONS sample], and one rural district—the district of Kielce [50 000 residents aged 45–64 years, including 5000 (10%) in the PONS sample]. These districts contain a diverse but stable mix of long-term residents. The study sites were carefully selected based on risk patterns of major chronic diseases, important exposure factors, economic development level, relative stability of the population, appropriate local infrastructure and long-term local commitment to the project.2 In the study area, all men and women aged 45–64 years who were permanent residents at the time of recruitment (110 000 eligible people) were invited to take part in the study. The recruitment was supported by a broad media campaign. During the limited time of baseline recruitment (16 months), the PONS study recruited 12% of the eligible population. The study was approved by the ethics committee within the Cancer Center and by the Institute of Oncology in Warsaw, Poland. Supplementary Figure 1 (available as Supplementary data at IJE online) presents several characteristic of the PONS cohort compared with the general population of Poland. Data on education level in Poland come from the National Census4 conducted in 2011. In the PONS cohort there are more men and women with higher education and fewerwith primary education and vocational training (P < 0.0001 at all education levels, but for women with secondary education P ¼ 0.1087). This probably reflects the recruitment by public announcement. Better educated people are more willing to participate in actions organized for the common good and higher education is also associated with higher health awareness. Data on smoking behaviour in Poland come from the GATS study5 conducted in 2009 on a representative sample of 7840 individuals (the age group 45–64 years used for comparison consisted of 2738 individuals). There are no differences between never smokers in either men or women (P ¼ 0.0644 for men and 0.3066 for women). However, the PONS cohort includes more ex-smokers and fewer current smokers than the general population (P < 0.0001). Data on prevalence of hypertension, coronary heart disease and stroke come from the Courage in Europe project6 that was performed on a Polish representative sample of 4071 individuals (the age group 40–69 years used for comparison consisted of 1863 individuals). Differences between the PONS cohort and the representative Polish sample were noted for hypertension, which seemed to be lower for men (P < 0.0001) but higher for women (P ¼ 0.038) in the PONS cohort. The Courage in Europe
Downloaded from http://ije.oxfordjournals.org/ at Dalhousie University on May 17, 2015
One-third of Polish men do not live to the age of 65 years. Poland is still facing a considerable gap in health that separates it from Western European countries, despite its rapid economic and social development in the past decades. There is a need to understand underlying causes of the health gap, especially in the context of premature mortality. Much health disparity research in the European region, including the Health Evolution Monitoring (HEM) – Closing the Gap project,1 aimed at understanding and defining mechanisms and lifestyle factors contributing to this epidemiological pattern. However, many questions are still unresolved. Before PONS was established, there were limited longitudinal data resources in the Central-Eastern Europe region that could provide an appropriate explanation for the existing disparities. Research on preventable risk factors of non-communicable diseases will provide the evidence necessary to prepare effective intervention programmes for health improvement on a national scale. The Polish-Norwegian Study (PONS) is an open-ended prospective cohort study in the south-eastern part of Poland (city and district of Kielce). It was designed to assess behavioural, biological, genetic, social and environmental factors with the aim of documenting the need for and laying the ground for developing effective health improvement strategies in the studied population. Its main aim is to study the impact of lifestyle and biological risk factors on aspects of health, such as the incidence of chronic diseases and quality of life. The Norwegian HUNT Study served as a blueprint for the PONS study design.2 The primary objectives of the PONS study are to: (i) describe mortality and morbidity characteristics of the most prevalent chronic diseases such as cardiovascular diseases, diabetes mellitus and cancer; (ii) identify environmental risk factors (lifestyle, diet, occupational) and life-course determinants of common chronic diseases; (iii) assess the effects of both established and emerging risk factors for different diseases, both overall and in subgroups of the population (e.g. at different ages and at different levels of other risk factors); (iv) measure and describe impact of socioeconomic changes on health; and (v) provide framework for intervention studies. The study is aimed at a broad spectrum of hypotheses, with respect to both exposures and outcomes. Both blood (plasma and buffy coat) and urine samples were obtained from a large number of participants; the study will therefore allow reliable assessment of many genetic and other biological factors that will be proposed as potential correlates or determinants of common chronic diseases.3
International Journal of Epidemiology, 2015, Vol. 0, No. 0
International Journal of Epidemiology, 2015, Vol. 0, No. 0
project groups used for comparison were slightly older that the PONS cohort participants, and this may explain some of the differences. In relation to similarities and differences between cohort data and nationally representative samples or census data, one must keep in mind that the PONS cohort was designed as a longitudinal study. Recruitment in PONS was based on voluntary participation, and the cohort is not a representative sample of the local or the national population. Whereas this feature of the study does not affect the internal validity of its results, caution should be applied if results are applied beyond the cohort itself (external validity or generalizability).7
It has been possible to link PONS participants to the National Cancer Registry where participants can be followed up electronically. Up to 2012, 672 (5%) cancer cases were identified. Among those cases, 463 had been diagnosed prior to study entry and 209 cancer cases were registered after entry. Data in the Polish National Cancer Registry have been available since the mid 1960s. There were 44 deaths reported among the PONS participants at the last date of linkage (10 October 2014). It is planned to follow up the cancer information annually, and approximately 100 new cancer cases are expected each year, with a gradual increase due to the ageing of the cohort. Additionally, the National Cancer Registry provides histopathological information on cancer diagnoses, allowing both confirmation and specific types of cancer to be assessed. The 6-year full follow-up is currently being prepared. All PONS participants are planned to be re-invited to one assessment centre in the city of Kielce for re-examination, including a questionnaire, clinical assessments and biological sample collection.
What has been measured? PONS participants were enrolled after signing an informed consent, which allows all collected data (including biological specimens) to be used for research purposes even if these are of no direct benefit to the participants. The consent is not time limited. An extensive questionnaire (Health Status Questionnaire or HSQ) was answered by all participants. Information was collected by a trained nurse via face-to-face interview and covered a broad range of variables including: socioeconomic status; demographic characteristics; prevalent diseases and long-term medication; reproductive history (women); family history of diseases; psychological status; smoking status and alcohol
consumption; dietary questions (Food Frequency Questionnaire or FFQ); and enquiries about physical activity (International Physical Activity Questionnaire or IPAQ). Supplementary Table 1 (available as Supplementary data at IJE online) gives a general overview of the content of the questionnaire. Participants also underwent several medical check-ups and measurements, according to the study protocol: blood pressure; heart rate; ECG; lung function (FEV1 and FVC); CO level in exhaled air; height; weight; and waist/hip circumference (Supplementary Table 2, available as Supplementary data at IJE online, summarizes the clinical examination and information about the equipment used). Blood and urine samples were also collected. Participants were asked to show up for the enrolment visit in a fasting state. If this condition was not met, a next-day morning visit was scheduled solely for biological sample collection. Supplementary Table 3 (available as Supplementary data at IJE online) summarizes information about the biological samples collected and stored in the biobank. All information collected was entered directly into a computer using a laptop-based data entry system developed specifically for the project. The data underwent regular quality assurance procedures conducted by specialists from the Warsaw University of Technology. The purpose of these procedures was to provide reliability estimates and checks against any serious organizational failure. Computer programs were developed to check the logic and reasonable range of responses and to identify contradictory responses or erroneous data.8 The same team merged and performed initial cleaning of the collected data for public availability after deidentification.
Key findings and publications Selected characteristic distributions of participants have been listed in Table 1. Mean age at baseline was 56 years. The majority of PONS cohort members were married or in co-habiting relationships; a higher proportion of men than women fit these categories. Greater than half of the cohort members were employed full-time at baseline. In the 45–54-year age group, the proportion of full-time employment was substantially higher (82% in men and 77% in women); one-third of the cohort was retired; 60% of cohort members lived in the predefined urban area; and 40% lived in the rural area. These proportions were similar across age groups and sexes. PONS cohort members assessed their general health as an average of 7 (on a scale of 1 to 10, with 10 representing ‘‘best health’’). However, elderly women assessed their health at an average of 6 on the same scale. Women in rural areas rated their health lower
Downloaded from http://ije.oxfordjournals.org/ at Dalhousie University on May 17, 2015
How often has the cohort been followed up?
3
4
International Journal of Epidemiology, 2015, Vol. 0, No. 0
Table 1. Basic characteristics of participants: PONS study, Poland 2010–11 Characteristics
Valid N (%)
Men aged 45–54
Men aged 55–64
Women aged 45–54
Women aged 55–64
13172 (100) 56 (65)
1776 50 (63)
2671 60 (63)
3647 50 (63)
5078 59 (63)
10292 (79) 1975 (15) 725 (6)
1531 (88) 112 (6) 112 (6)
2369 (90) 181 (7) 85 (3)
2849 (79) 531 (15) 215 (6)
3543 (71) 1151 (23) 313 (6)
1149 (9) 2732 (21) 5287 (41) 3835 (29)
77 (4) 559 (32) 634 (36) 486 (28)
226 (8) 767 (29) 939 (36) 708 (27)
203 (6) 702 (20) 1345 (37) 1346 (37)
643 (13) 704 (14) 2369 (47) 1295 (26)
6852 (53) 3982 (31) 922 (7) 1225 (9)
1439 (82) 66 (4) 86 (5) 162 (9)
1276 (48) 834 (32) 348 (13) 179 (7)
2767 (77) 94 (3) 146 (4) 580 (16)
1370 (27) 2988 (60) 342 (7) 304 (6)
2556 (27) 4621 (49) 2294 (24)
172 (14) 474 (40) 540 (46)
411 (22) 877 (46) 620 (32)
729 (29) 1192 (47) 605 (24)
1244 (32) 2078 (54) 529 (14)
8037 (62) 4964 (38)
1002 (57) 753 (43)
1672 (63) 968 (37)
2075 (58) 1520 (42)
3288 (66) 1723 (34)
7 (61) 978 (8) 11208 (87) 677 (5)
7 (61) 165 (9) 1499 (87) 68 (4)
7 (61) 194 (7) 2248 (86) 169 (6)
7 (61) 333 (9) 3099 (87) 128 (4)
6 (61) 286 (6) 4362 (88) 312 (6)
6000 (46) 4386 (34) 2612 (20)
648 (37) 674 (38) 433 (25)
874 (33) 1223 (46) 543 (21)
1873 (52) 921 (26) 801 (22)
2605 (52) 1568 (31) 835 (17)
1981(15) 11016 (85)
161 (9) 1595 (91)
283 (11) 2357 (89)
483 (13) 3109 (87)
1054 (21) 3955 (79)
5579 (70) 2062 (26) 322 (4)
664 (48) 574 (42) 137 (10)
1076 (56) 686 (36) 147 (8)
1726 (78) 454 (21) 17 (1)
2113 (85) 348 (14) 21 (1)
3405 (26) 5727 (44) 3976 (30)
377 (21) 885 (50) 504 (29)
431 (16) 1351 (51) 875 (33)
1406 (39) 1410 (39) 812 (22)
1191 (24) 2081 (41) 1785 (35)
180
169
191
3701
171
309
174
175
5209
64
a
Including self-employed and farmers. Including retired, and part-time workers. c Average net monthly per capita (13716 net yearly per capita in eastern region of Poland). PLN denotes Polish zloty, the official currency of Poland. d Defined as individuals who did not consume any alcoholic beverage during the past 12 months. b
than men in rural areas, and women in the urban area also rated their health lower than men in the rural areas. This may indicate that sex is a stronger self-assessed health predictor than rural or urban residence.
One-fifth of cohort members were current smokers. The prevalence of current smoking was highest in older men (46%). More than half of the women in the cohort were never smokers. A majority of the cohort members reported
Downloaded from http://ije.oxfordjournals.org/ at Dalhousie University on May 17, 2015
Demographics Age at baseline (mean) Marital status Married/living together Separated/divorced/widowed Never married/single Education Primary Vocational Secondary Higher Employment status Full-time employeda Retiredb Sick or disabled Unemployed Income 2500 pln net/cap/month Place of residence Urban Rural Self-rated health state (scale 1-worst to 10-best) Mean (SD) 9-10 5-8 1-4 Lifestyle profile Smoking Never smokers Ex-smokers Current smokers Alcohol Abstainers d Consumers Among consumers (last 30 days): 1-3 days a month 1-3 days a week Daily or most days Body mass index
Cohort Profile
Cohort Profile: The Polish-Norwegian Study (PONS) cohort Marta Manczuk,1* Paolo Boffetta,2 Samantha Sartori,2 Dana Hashim,2 Lars J Vatten3 and Witold A Zatonski1 1
Downloaded from http://ije.oxfordjournals.org/ at Dalhousie University on May 17, 2015
Department of Cancer Epidemiology, Maria Sklodowska-Curie Memorial Cancer Center and Institute of Oncology, Warsaw, Poland, 2Icahn School of Medicine at Mount Sinai, New York, NY, USA and 3 Norwegian University of Science and Technology, Trondheim, Norway *Corresponding author. Department of Cancer Epidemiology, Maria Sklodowska-Curie Memorial Cancer Center and Institute of Oncology, 02-034 Warszawa, ul. Wawelska 15B, Poland. E-mail: [email protected]
Abstract The PONS cohort is a longitudinal observational regional study collecting information on health and health-related behaviours in the south-eastern part of Poland. The study aims at providing information on determinants of health differences between Poland and other countries in the region, especially related to premature mortality. The baseline data collection contains records for 13 172 individuals (2010–11), between 45 and 64 years of age, from the city of Kielce and surrounding rural area. All cohort members were volunteer participants and gave informed consent prior to inclusion. Data were collected on current health status, medical history and health-related behaviours with focus on preventable causes of chronic diseases, including tobacco smoking, alcohol consumption, physical activity and dietary habits. In addition to an extensive questionnaire, blood and urine samples were collected for storage. The study is expected to provide valuable evidence related to various lifestyle behaviours and health, and insight into the usefulness of population approaches for preventive interventions in Polish communities. To access data or biological material or to use the sample to recruit participants for new studies, researchers should contact the principal investigator, Witold A Zatonski at: [[email protected]].
Key Messages • Initial PONS findings provide a detailed description of the study population indicating areas that may require inter-
ventions and providing valuable information for regional health policy. • The PONS study offers a valuable data source, including biological material that can serve various research purposes
thanks to a broad consent form. • Baseline data collection revealed a high prevalence of non-communicable chronic diseases but drew also attention to
poorly controlled common conditions, such as hypertension and diabetes. C The Author 2015; all rights reserved. Published by Oxford University Press on behalf of the International Epidemiological Association V
1
2
Why was the cohort set up?
Who is in the cohort? In the first phase, between September 2010 and December 2011, PONS recruited 13 172 adults aged 45–64 years
from the general populations of two geographically distinct regions: one urban district—the city of Kielce [60 000 residents aged 45–64 years, of whom 8000 (13%) were included in the PONS sample], and one rural district—the district of Kielce [50 000 residents aged 45–64 years, including 5000 (10%) in the PONS sample]. These districts contain a diverse but stable mix of long-term residents. The study sites were carefully selected based on risk patterns of major chronic diseases, important exposure factors, economic development level, relative stability of the population, appropriate local infrastructure and long-term local commitment to the project.2 In the study area, all men and women aged 45–64 years who were permanent residents at the time of recruitment (110 000 eligible people) were invited to take part in the study. The recruitment was supported by a broad media campaign. During the limited time of baseline recruitment (16 months), the PONS study recruited 12% of the eligible population. The study was approved by the ethics committee within the Cancer Center and by the Institute of Oncology in Warsaw, Poland. Supplementary Figure 1 (available as Supplementary data at IJE online) presents several characteristic of the PONS cohort compared with the general population of Poland. Data on education level in Poland come from the National Census4 conducted in 2011. In the PONS cohort there are more men and women with higher education and fewerwith primary education and vocational training (P < 0.0001 at all education levels, but for women with secondary education P ¼ 0.1087). This probably reflects the recruitment by public announcement. Better educated people are more willing to participate in actions organized for the common good and higher education is also associated with higher health awareness. Data on smoking behaviour in Poland come from the GATS study5 conducted in 2009 on a representative sample of 7840 individuals (the age group 45–64 years used for comparison consisted of 2738 individuals). There are no differences between never smokers in either men or women (P ¼ 0.0644 for men and 0.3066 for women). However, the PONS cohort includes more ex-smokers and fewer current smokers than the general population (P < 0.0001). Data on prevalence of hypertension, coronary heart disease and stroke come from the Courage in Europe project6 that was performed on a Polish representative sample of 4071 individuals (the age group 40–69 years used for comparison consisted of 1863 individuals). Differences between the PONS cohort and the representative Polish sample were noted for hypertension, which seemed to be lower for men (P < 0.0001) but higher for women (P ¼ 0.038) in the PONS cohort. The Courage in Europe
Downloaded from http://ije.oxfordjournals.org/ at Dalhousie University on May 17, 2015
One-third of Polish men do not live to the age of 65 years. Poland is still facing a considerable gap in health that separates it from Western European countries, despite its rapid economic and social development in the past decades. There is a need to understand underlying causes of the health gap, especially in the context of premature mortality. Much health disparity research in the European region, including the Health Evolution Monitoring (HEM) – Closing the Gap project,1 aimed at understanding and defining mechanisms and lifestyle factors contributing to this epidemiological pattern. However, many questions are still unresolved. Before PONS was established, there were limited longitudinal data resources in the Central-Eastern Europe region that could provide an appropriate explanation for the existing disparities. Research on preventable risk factors of non-communicable diseases will provide the evidence necessary to prepare effective intervention programmes for health improvement on a national scale. The Polish-Norwegian Study (PONS) is an open-ended prospective cohort study in the south-eastern part of Poland (city and district of Kielce). It was designed to assess behavioural, biological, genetic, social and environmental factors with the aim of documenting the need for and laying the ground for developing effective health improvement strategies in the studied population. Its main aim is to study the impact of lifestyle and biological risk factors on aspects of health, such as the incidence of chronic diseases and quality of life. The Norwegian HUNT Study served as a blueprint for the PONS study design.2 The primary objectives of the PONS study are to: (i) describe mortality and morbidity characteristics of the most prevalent chronic diseases such as cardiovascular diseases, diabetes mellitus and cancer; (ii) identify environmental risk factors (lifestyle, diet, occupational) and life-course determinants of common chronic diseases; (iii) assess the effects of both established and emerging risk factors for different diseases, both overall and in subgroups of the population (e.g. at different ages and at different levels of other risk factors); (iv) measure and describe impact of socioeconomic changes on health; and (v) provide framework for intervention studies. The study is aimed at a broad spectrum of hypotheses, with respect to both exposures and outcomes. Both blood (plasma and buffy coat) and urine samples were obtained from a large number of participants; the study will therefore allow reliable assessment of many genetic and other biological factors that will be proposed as potential correlates or determinants of common chronic diseases.3
International Journal of Epidemiology, 2015, Vol. 0, No. 0
International Journal of Epidemiology, 2015, Vol. 0, No. 0
project groups used for comparison were slightly older that the PONS cohort participants, and this may explain some of the differences. In relation to similarities and differences between cohort data and nationally representative samples or census data, one must keep in mind that the PONS cohort was designed as a longitudinal study. Recruitment in PONS was based on voluntary participation, and the cohort is not a representative sample of the local or the national population. Whereas this feature of the study does not affect the internal validity of its results, caution should be applied if results are applied beyond the cohort itself (external validity or generalizability).7
It has been possible to link PONS participants to the National Cancer Registry where participants can be followed up electronically. Up to 2012, 672 (5%) cancer cases were identified. Among those cases, 463 had been diagnosed prior to study entry and 209 cancer cases were registered after entry. Data in the Polish National Cancer Registry have been available since the mid 1960s. There were 44 deaths reported among the PONS participants at the last date of linkage (10 October 2014). It is planned to follow up the cancer information annually, and approximately 100 new cancer cases are expected each year, with a gradual increase due to the ageing of the cohort. Additionally, the National Cancer Registry provides histopathological information on cancer diagnoses, allowing both confirmation and specific types of cancer to be assessed. The 6-year full follow-up is currently being prepared. All PONS participants are planned to be re-invited to one assessment centre in the city of Kielce for re-examination, including a questionnaire, clinical assessments and biological sample collection.
What has been measured? PONS participants were enrolled after signing an informed consent, which allows all collected data (including biological specimens) to be used for research purposes even if these are of no direct benefit to the participants. The consent is not time limited. An extensive questionnaire (Health Status Questionnaire or HSQ) was answered by all participants. Information was collected by a trained nurse via face-to-face interview and covered a broad range of variables including: socioeconomic status; demographic characteristics; prevalent diseases and long-term medication; reproductive history (women); family history of diseases; psychological status; smoking status and alcohol
consumption; dietary questions (Food Frequency Questionnaire or FFQ); and enquiries about physical activity (International Physical Activity Questionnaire or IPAQ). Supplementary Table 1 (available as Supplementary data at IJE online) gives a general overview of the content of the questionnaire. Participants also underwent several medical check-ups and measurements, according to the study protocol: blood pressure; heart rate; ECG; lung function (FEV1 and FVC); CO level in exhaled air; height; weight; and waist/hip circumference (Supplementary Table 2, available as Supplementary data at IJE online, summarizes the clinical examination and information about the equipment used). Blood and urine samples were also collected. Participants were asked to show up for the enrolment visit in a fasting state. If this condition was not met, a next-day morning visit was scheduled solely for biological sample collection. Supplementary Table 3 (available as Supplementary data at IJE online) summarizes information about the biological samples collected and stored in the biobank. All information collected was entered directly into a computer using a laptop-based data entry system developed specifically for the project. The data underwent regular quality assurance procedures conducted by specialists from the Warsaw University of Technology. The purpose of these procedures was to provide reliability estimates and checks against any serious organizational failure. Computer programs were developed to check the logic and reasonable range of responses and to identify contradictory responses or erroneous data.8 The same team merged and performed initial cleaning of the collected data for public availability after deidentification.
Key findings and publications Selected characteristic distributions of participants have been listed in Table 1. Mean age at baseline was 56 years. The majority of PONS cohort members were married or in co-habiting relationships; a higher proportion of men than women fit these categories. Greater than half of the cohort members were employed full-time at baseline. In the 45–54-year age group, the proportion of full-time employment was substantially higher (82% in men and 77% in women); one-third of the cohort was retired; 60% of cohort members lived in the predefined urban area; and 40% lived in the rural area. These proportions were similar across age groups and sexes. PONS cohort members assessed their general health as an average of 7 (on a scale of 1 to 10, with 10 representing ‘‘best health’’). However, elderly women assessed their health at an average of 6 on the same scale. Women in rural areas rated their health lower
Downloaded from http://ije.oxfordjournals.org/ at Dalhousie University on May 17, 2015
How often has the cohort been followed up?
3
4
International Journal of Epidemiology, 2015, Vol. 0, No. 0
Table 1. Basic characteristics of participants: PONS study, Poland 2010–11 Characteristics
Valid N (%)
Men aged 45–54
Men aged 55–64
Women aged 45–54
Women aged 55–64
13172 (100) 56 (65)
1776 50 (63)
2671 60 (63)
3647 50 (63)
5078 59 (63)
10292 (79) 1975 (15) 725 (6)
1531 (88) 112 (6) 112 (6)
2369 (90) 181 (7) 85 (3)
2849 (79) 531 (15) 215 (6)
3543 (71) 1151 (23) 313 (6)
1149 (9) 2732 (21) 5287 (41) 3835 (29)
77 (4) 559 (32) 634 (36) 486 (28)
226 (8) 767 (29) 939 (36) 708 (27)
203 (6) 702 (20) 1345 (37) 1346 (37)
643 (13) 704 (14) 2369 (47) 1295 (26)
6852 (53) 3982 (31) 922 (7) 1225 (9)
1439 (82) 66 (4) 86 (5) 162 (9)
1276 (48) 834 (32) 348 (13) 179 (7)
2767 (77) 94 (3) 146 (4) 580 (16)
1370 (27) 2988 (60) 342 (7) 304 (6)
2556 (27) 4621 (49) 2294 (24)
172 (14) 474 (40) 540 (46)
411 (22) 877 (46) 620 (32)
729 (29) 1192 (47) 605 (24)
1244 (32) 2078 (54) 529 (14)
8037 (62) 4964 (38)
1002 (57) 753 (43)
1672 (63) 968 (37)
2075 (58) 1520 (42)
3288 (66) 1723 (34)
7 (61) 978 (8) 11208 (87) 677 (5)
7 (61) 165 (9) 1499 (87) 68 (4)
7 (61) 194 (7) 2248 (86) 169 (6)
7 (61) 333 (9) 3099 (87) 128 (4)
6 (61) 286 (6) 4362 (88) 312 (6)
6000 (46) 4386 (34) 2612 (20)
648 (37) 674 (38) 433 (25)
874 (33) 1223 (46) 543 (21)
1873 (52) 921 (26) 801 (22)
2605 (52) 1568 (31) 835 (17)
1981(15) 11016 (85)
161 (9) 1595 (91)
283 (11) 2357 (89)
483 (13) 3109 (87)
1054 (21) 3955 (79)
5579 (70) 2062 (26) 322 (4)
664 (48) 574 (42) 137 (10)
1076 (56) 686 (36) 147 (8)
1726 (78) 454 (21) 17 (1)
2113 (85) 348 (14) 21 (1)
3405 (26) 5727 (44) 3976 (30)
377 (21) 885 (50) 504 (29)
431 (16) 1351 (51) 875 (33)
1406 (39) 1410 (39) 812 (22)
1191 (24) 2081 (41) 1785 (35)
180
169
191
3701
171
309
174
175
5209
64
a
Including self-employed and farmers. Including retired, and part-time workers. c Average net monthly per capita (13716 net yearly per capita in eastern region of Poland). PLN denotes Polish zloty, the official currency of Poland. d Defined as individuals who did not consume any alcoholic beverage during the past 12 months. b
than men in rural areas, and women in the urban area also rated their health lower than men in the rural areas. This may indicate that sex is a stronger self-assessed health predictor than rural or urban residence.
One-fifth of cohort members were current smokers. The prevalence of current smoking was highest in older men (46%). More than half of the women in the cohort were never smokers. A majority of the cohort members reported
Downloaded from http://ije.oxfordjournals.org/ at Dalhousie University on May 17, 2015
Demographics Age at baseline (mean) Marital status Married/living together Separated/divorced/widowed Never married/single Education Primary Vocational Secondary Higher Employment status Full-time employeda Retiredb Sick or disabled Unemployed Income 2500 pln net/cap/month Place of residence Urban Rural Self-rated health state (scale 1-worst to 10-best) Mean (SD) 9-10 5-8 1-4 Lifestyle profile Smoking Never smokers Ex-smokers Current smokers Alcohol Abstainers d Consumers Among consumers (last 30 days): 1-3 days a month 1-3 days a week Daily or most days Body mass index
