Geographic access to mammography screening centre and participation of women in the Quebec Breast Cancer Screening Programme

Transcription

1 JECH Online First, published on July 13, 2013 as /jech Research report Geographic access to mammography screening centre and participation of women in the Quebec Breast Cancer Screening Programme Sylvie St-Jacques, 1 Mathieu D Philibert, 2 André Langlois, 1 Jean-Marc Daigle, 1 Éric Pelletier, 1 Diane Major, 1 Jacques Brisson 1,3 1 Direction de l Analyse et de l Évaluation des Systèmes de Soins et Services, Institut National de Santé Publique du Québec, Québec, Québec, Canada 2 Vice-présidence aux affaires scientifiques, Institut National de Santé Publique du Québec, Montreal, Quebec, Canada 3 Département de Médecine Sociale et Préventive, Centre de Recherche du CHU de Québec, Université Laval, Québec, Québec, Canada Correspondence to Eric Pelletier, Direction de l Analyse et de l Évaluation des Systèmes de Soins et Services, Institut National de Santé Publique du Quebec, Quebec, Quebec, Canada G1V 5B3; eric.pelletier@inspq.qc.ca Received 18 March 2013 Revised 6 June 2013 Accepted 18 June 2013 To cite: St-Jacques S, Philibert MD, Langlois A, et al. J Epidemiol Community Health Published Online First: [ please include Day Month Year] doi: /jech ABSTRACT Background This study evaluated the impact of distance between women s residences and designated screening centres (DSC) on participation in the Quebec Breast Cancer Screening Programme, whether this impact varied according to the rural urban classification and the proportion of participants who used the DSC nearest to their home. Methods Travel distance between the residence of women and the nearest DSC (n=85) was estimated. Data were obtained from administrative and screening programme databases. The analysis made use of a log-binomial regression model adjusting for age and material and social deprivation. The proportions of participants who used the DSC nearest to their residence were measured. Results Compared to women living <2.5 km from a DSC, absolute decreases of 6.3% and 9.8% in participation rate were observed for distances of 50.0 to <75.0 km (rate ratios (RR)=0.88, 95% CI 0.86 to 0.89) and 75.0 km (RR=0.81, 95% CI 0.79 to 0.83), respectively. The lowest participation (42%) was observed in Montreal Island. The distance at which participation started to decrease materially varied according to rural urban classification. Participation rates decreased at distances of 25.0 km in the Montreal suburbs and midsize cities, at 12.5 km in small cities and at 50.0 km in rural areas (interaction p<0.0001). The proportion of participants who had their mammography at the nearest DSC decreased with increasing distance. Conclusions Distance affects participation and this effect varies according to rural urban classification. The lower participation in Montreal Island, where all women lived <12.5 km from a DSC, argues for a major impact of other characteristics or other dimensions of accessibility. INTRODUCTION Evidence suggests that mammography programme screening contributes to reductions in breast cancer mortality, particularly among women aged However, adequate participation in mammography screening programmes is essential for reductions in mortality to occur. The Quebec Breast Cancer Screening Programme, launched in 1998, offers free screening mammography on a biennial basis to women aged years. Although participation in the programme has grown steadily, participation rates in many areas of Quebec remain below the target of 70%. 2 Only a small number of women living in the most remote areas of the province are mainly served by mobile units. Most women (98%) are served by programme-designated screening centres (DSC). However, distances to DSCs vary substantially, and some women have to travel long distances to reach a DSC. Many studies reported that increased distance to screening facilities was associated with decreased participation in breast cancer screening. 3 9 Others observed that the probability of using mammography was not affected by physical distance to mammography facilities, but rather by the mammography facility density, which measures the number of facilities within a designated area. Furthermore, the percentage of persons living in rural area within a designated area was also associated with the probability of having had a mammogram. 10 Many studies reported that women living in rural areas were less likely to have mammography screening, or to reattend a second round of screening, than their urban counterparts. However, to the best of our knowledge, no study to date has investigated whether the rural urban classification modifies the impact of distance on participation in breast cancer screening and whether participants really use the facility nearest to their home. The objectives of the current study therefore were threefold: (1) to evaluate the impact of distance on the participation of women in the Quebec Breast Cancer Screening Programme, (2) to assess whether the rural urban classification modifies the relation of distance to participation and (3) to calculate the proportion of participants who used the DSC nearest to their residence. METHODS Populations All Quebec women who were aged years on 15 October 2008 were identified using the comprehensive Quebec Health Insurance Plan database. For the purposes of the current study, women who lived in remote areas where screening mammography is mainly provided by mobile units and those for whom an address could not be localised geographically were excluded from the target population. Distance to the nearest screening centre Complete addresses were used to localise the residences of women and the 85 DSCs operating in at the street-block level. For each Copyright Article author (or their employer) Produced by BMJ Publishing Group Ltd under licence. St-Jacques S, et al. J Epidemiol Community Health 2013;0:1 7. doi: /jech

2 woman, the shortest driving distance between residential location and the nearest DSC was estimated using ArcGIS Network Analyst (V.9.2). Rural urban classification A five-level rural urban classification was created based on a classification developed from Statistics Canada. 17 The Greater Montreal area was considered separately from other urban areas (approximately half of the province s population is located in the Greater Montreal area) and, within Greater Montreal, the core of the city was considered separately from the suburbs. Thus, the Quebec territory was classified in 5 rural urban categories: Montreal Island, Montreal suburbs, midsize cities (more than inhabitants), small cities ( inhabitants), and villages and rural areas (municipalities with less than inhabitants). Quebec midsize cities include Quebec City, Sherbrooke, Trois-Rivières, Saguenay and Ottawa-Hull (only the portion located in the province of Quebec). Socioeconomic status The socioeconomic status (SES) of women was considered a potential confounder for its known association with mammography usage 18 and its association with distance and rural urban classification (from preliminary analysis). Because individuallevel socioeconomic information was not available in the administrative databases used for this study, an area-based deprivation index was used as an ecological proxy for SES. 19 The index is produced using a principal component analysis at the dissemination-area level, which constitutes the smallest geographic unit for which census data are available (565±256 individuals in 2006). 20 The deprivation index consists of two factors, one reflecting material deprivation (ie, proportion of respondents with no high school diploma, employment/population ratio and average income), the other reflecting social deprivation (ie, proportion of respondents living alone, proportion of individuals separated, divorced or widowed and proportion of single-parent families). Dissemination area factor scores were subsequently classified into population quintiles. The deprivation index covers approximately 98% of the province s population. Some areas are not covered due to lack of census data. Participation assessment Data related to participation in the screening programme were obtained from the information system of the Quebec Breast Cancer Screening Programme. A woman participated in the screening programme if she had a screening mammogram within the programme between 16 October 2006 and 15 October 2008, inclusively, and if she signed an informed consent to participate in the programme. In the period under study, 97.7% of women who had screening mammograms signed this consent. Since calculation of participation rates requires screening data over the previous 2 years, participation could be investigated only among women who were aged years in When a woman had a screening mammogram, the DSC where she obtained her mammogram was identified. Data analysis The association between participation rates and distance was estimated using log-binomial regression models (GENMOD procedure in SAS release V.9.2, SAS Institute Inc, Cary, North Carolina, USA). 21 The model included distance categories (<2.5 km, 2.5 to <5.0 km, 5.0 to <12.5 km, 12.5 km to <25.0, 25.0 to <50.0, 50.0 to <75.0 and 75.0 km), age groups (52 54, 55 59, and 65 69), rural urban categories (Montreal Island, Montreal suburbs, midsize cities, small cities and rural areas) and social and material deprivation indices (quintiles). In the analysis of the modifying effect of rural-urban classification, interaction terms between distance and rural urban classification were added. Because of the large number of women in most categories, even marginal differences in participation rates reach statistical significance. For this reason, we considered participation rate ratios (RR) of 1.05 or 0.95 to be meaningful in terms of public health significance. The proportion of participants who had their mammogram at the nearest DSC was calculated based on the screening location used by women who participated in the programme. RESULTS The Quebec population included women aged between 50 and 69 years on 15 October Women who lived in remote areas where screening mammography is mainly provided by mobile units (n=2492, 0.25%) and women for whom an address could not be localised geographically (n=14 731, 1.5%) were excluded, leaving a target population of women. To study the impact of distance on participation in the screening programme, women were excluded if they were aged 50 or 51 years (n= , 12.9%) and if no deprivation index was available for the location of their residence (n=24 652, 2.9%). Consequently, the study population consisted of women aged years (mean age=59 years) who were living at a mean driving distance of 11.3 km (median 5.3 km) from their nearest DSC. The target and the study populations showed similar distributions for distance and rural urban classification (table 1). About 74% of women lived <12.5 km from their nearest DSC and 3% were located 50.0 km or more away. Table 2 shows characteristics according to distance categories. Women residing <2.5 km from their nearest DSC were predominantly located in Montreal Island (39.3%); a high proportion of them (65%) were socially deprived (quintile 4 and quintile 5). On the other end of the scale, nearly all women who were living 50.0 km from their nearest DSC were located in rural areas Table 1 Characteristics of the target and study populations Target population, N (%) Study population, N (%) Distance to the nearest screening centre, km < (25.8) (25.7) 2.5 to < (22.8) (22.7) 5.0 to < (25.8) (25.7) 12.5 to < (12.7) (12.7) 25.0 to < (9.7) (9.9) 50.0 to < (2.3) (2.4) (0.9) 8061 (1.0) Rural urban categories Montreal Island (22.2) (22.1) Montreal suburbs (22.8) (23.2) Midsize cities* (21.2) (20.7) Small cities (13.0) (12.9) Rural areas (20.8) (21.1) Total (100.0) (100.0) *Midsize city areas: Quebec City, Sherbrooke, Trois-Rivières, Saguenay and Ottawa-Hull (only the portion located in the province of Quebec). 2 St-Jacques S, et al. J Epidemiol Community Health 2013;0:1 7. doi: /jech

3 Table 2 Distribution of women according to their characteristics by distance categories Distance to the nearest DSC, km (%) <2.5, N= to <5.0, N= to <12.5, N= to <25.0, N= to <50.0, N= to <75.0, N= , N=8061 Rural urban categories Montreal Island Montreal suburbs Midsize cities* Small cities Rural areas Age in years Material deprivation Quintile 1 (lowest) Quintile Quintile Quintile Quintile 5 (highest) Social deprivation Quintile 1 (lowest) Quintile Quintile Quintile Quintile 5 (highest) *Midsize city areas: Quebec, Sherbrooke, Trois-Rivieres, Saguenay and Ottawa-Hull (only the portion located in the province of Quebec). DSC, programme-designed screening centre. (98.3%). A high proportion of these women were materially deprived (70%) but around 60% were distributed in the lower quintiles (quintile 1 and quintile 2) of social deprivation. Age distribution was similar across distance categories. Associations between women s characteristics and participation in the screening programme are reported in table 3. The overall participation rate was 52.1%. Except for age, all characteristics were associated with participation and these associations persisted in the adjusted model, which included all the variables. Compared to women who lived <2.5 km from a DSC, decreases in participation rates became clearer for distances of 50.0 km or more. Absolute decreases of 6.3% and 9.8% in participation rates occurred among women living at 50.0 to <75.0 km (RR 0.88, 95% CI 0.86 to 0.89) and 75.0 km (RR 0.81, 95% CI 0.79 to 0.83) from the nearest DSC, respectively. The lowest participation rate was observed in Montreal Island (40.9%). Compared to women living in midsize cities where the highest participation rate was observed (57.6%), this represents an absolute reduction of 16.7% (RR=0.71, 95% CI 0.70 to 0.72). Lower decreases were observed for the Montreal suburbs (RR=0.90, 95% CI 0.90 to 0.91) while no meaningful decreases were seen in small cities (RR 0.99, 95% CI 0.98 to 0.99) and rural areas (RR 0.96, 95% CI 0.95 to 0.97). Material and social deprivation indices were both associated with decreases in participation. The most materially deprived women (quintile 5) showed an absolute decrease of 3.9% in their participation rate compared to the less deprived (RR=0.93, 95% CI 0.92 to 0.93). The participation of women within the two most socially deprived quintiles (quintile 4 and quintile 5) showed absolute decreases in participation of 3.6% (RR=0.93, 95% CI 0.93 to 0.94) and 5.2%, (RR=0.91, 95% CI 0.90 to 0.91), respectively. The association of distance to participation varied according to rural urban classification (interaction p value <0.0001; table 4). No meaningful impact of distance was observed in Montreal Island, where practically all women were living <12.5 km from a DSC. In the Montreal suburbs and midsize cities, decreases in participation rates were observed for distances of 25.0 km or more. In these areas, compared to women who lived <2.5 km from the nearest DSC, absolute decreases of 9.3% (RR=0.82, 95% CI 0.77 to 0.88) and 5.6% (RR=0.90, 95% CI 0.87 to 0.93), respectively, were noted for women who resided 25.0 to <50.0 km away. In small cities, reductions in participation were observed for distances of 12.5 km or more. For women who lived 12.5 to <25.0 km from their nearest DSC, an absolute decrease of 4.4% in participation rate was observed compare to those at <2.5 km (RR=0.92, 95% CI 0.90 to 0.94). Finally, in rural areas, a clear reduction in participation was first seen at distances of 50 km or more. In these areas, compared to women who lived <2.5 km from their nearest DSC, absolute decreases in participation rates of 5.6% (RR=0.90, 95% CI 0.88 to 0.92) and 10.0% (RR=0.82, 95% CI 0.80 to 0.85) were observed for distance categories 50.0 to <75 km and 75 km and more, respectively. The proportions of participants who used the nearest DSC are reported in table 5. Whatever rural urban category of residence, these proportions decreased with increasing distance. The lower proportion was observed in the metropolitan area of Montreal, particularly in Montreal Island where 44.7% of participants used the DSC nearest to their home. In small cities and St-Jacques S, et al. J Epidemiol Community Health 2013;0:1 7. doi: /jech

4 Table 3 Association of distance to the nearest screening centre, rural-urban classification, age, material and social deprivation with participation in the Quebec Breast Cancer Screening Programme Participation rate, % Unadjusted Adjusted* Ratio of adjusted participation rates (95% CI) Total 52.1 Distance to the nearest DSC, km < to < (1.00 to 1.01) 5.0 to < (0.99 to 1.00) 12.5 to < (0.96 to 0.97) 25.0 to < (0.95 to 0.97) 50.0 to < (0.86 to 0.89) (0.79 to 0.83) Rural urban categories Montreal Island (0.70 to 0.72) Montreal suburbs (0.90 to 0.91) Midsize cities Small cities (0.98 to 0.99) Rural areas (0.95 to 0.97) Age (years) (1.02 to 1.03) (1.04 to 1.05) (0.99 to 1.00) Material deprivation Quintile 1 (lowest) Quintile (0.98 to 1.00) Quintile (0.98 to 0.99) Quintile (0.96 to 0.97) Quintile 5 (highest) (0.92 to 0.93) Social deprivation Quintile 1 (lowest) Quintile (0.97 to 0.98) Quintile (0.95 to 0.96) Quintile (0.93 to 0.94) Quintile 5 (highest) (0.90 to 0.91) *The adjusted model included the following variables: age, distance to the nearest programme-designated screening Centre (DSC), rural urban classification, material and social deprivation. Midsize city areas: Quebec City, Sherbrooke, Trois-Rivières, Saguenay and Ottawa-Hull (only the portion located in the province of Quebec). rural areas around 90% of participants used the nearest DSC if it was located <12.5 km from their home. For distances of 12.5 km or more, proportions decreased with increasing distances. When the nearest DSC was at 50.0 km or more from their residence, about half of rural participants used another DSC. DISCUSSION We found that the participation of women in the Quebec Breast Cancer Screening Programme decreased as the distance to the nearest DSC increased, and that the shortest distance at which participation started to decrease materially varied according to rural urban classification. The majority (74%) of women targeted by the screening programme lived at less than 12.5 km from the nearest DSC, a distance that showed no impact on participation. However, around 15% of women were living at distances associated with meaningful decreases in participation rates. The choice of participants to use the DSC nearest from their residence also varied according to distance and rural urban classification. The results of the current study are consistent with those of previous studies that have reported an inverse relation between distance and participation in breast cancer screening programmes Apart from Montreal Island, we observed that increasing distances were significantly associated with decreases in participation rates, whatever the rural urban category. However, the impact of distance varied according to rural urban classification. Meaningful decreases in participation rates were observed from distances of 12.5 km in the Montreal suburbs and small city areas, 25.0 km in midsize city areas and 50.0 km in rural areas. Women who live in rural areas seem to be less sensitive to distance than their urban counterparts. People from rural areas often must travel longer distances to reach services, and this might account for their increased tolerance to distance. In an urban environment, the impact of distance is influenced by factors such as traffic volume, time spent waiting for public transportation or time of the day. We observed the lowest participation rate in Montreal Island, which corresponds to a large part of the Montreal metropolitan area. This is in contrast with the literature suggesting that 4 St-Jacques S, et al. J Epidemiol Community Health 2013;0:1 7. doi: /jech

5 Table 4 Association of distance to the nearest designated screening centres (DSC) with participation in the screening programme according to rural urban classification Participation rates Rural urban categories Study population Unadjusted Adjusted* Ratio of adjusted participation rates (95% CI) Montreal Island < to < (0.97 to 0.99) 5.0 to < (0.95 to 0.97) 12.5 to < to <50.0 Montreal suburbs < to < (0.99 to 1.02) 5.0 to < (0.98 to 1.01) 12.5 to < (0.96 to 0.99) 25.0 to < (0.77 to 0.88) Midsize cities < to < (1.00 to 1.02) 5.0 to < (1.01 to 1.04) 12.5 to < (1.01 to 1.04) 25.0 to < (0.87 to 0.93) Small cities < to < (1.02 to 1.04) 5.0 to < (1.01 to 1.04) 12.5 to < (0.90 to 0.94) 25.0 to < (0.58 to 0.65) Rural areas < to < (0.99 to 1.06) 5.0 to < (0.94 to 0.99) 12.5 to < (0.93 to 0.97) 25.0 to < (0.97 to 1.01) 50.0 to < (0.88 to 0.92) (0.80 to 0.85) *The adjusted model included age, material and social deprivation. Less than 100 individuals. Midsize city areas: Quebec City, Sherbrooke, Trois-Rivières, Saguenay and Ottawa-Hull (only the portion located in the province of Quebec). women living in urban areas were more likely to have mammography screening The participation rate of around 40% persists after taking into account distance, age, material and social deprivation. This result is in agreement with what has been called a rural urban paradox in a study of access to primary care in the province of Quebec. 24 In that study, positive evaluation of primary healthcare, in almost all dimensions of access, continuity, responsiveness and use of services, including screening, was reported to be higher for rural users than for users within the urban core of Montreal or Quebec City. One might consider different potential explanations for the low participation in Montreal Island. Most of Quebec s immigrants choose to live in the census metropolitan area of Montreal. These individuals represented around 20% of Montreal s population. 25 In a large multicultural city such as Montreal, community characteristics are likely to influence the health behaviours of individuals. Statistics Canada 26 and the US National Health Interview Survey 27 have reported that women who immigrated within the last 10 years were less likely to have had a mammogram within the last 2 years. Comparison of mammography rates in Toronto s inner city in the year 2000 revealed that areas of high recent immigration had low mammography use, independent of income effects. 28 Greater availability of opportunistic screening outside of the Quebec Breast Cancer St-Jacques S, et al. J Epidemiol Community Health 2013;0:1 7. doi: /jech

6 Table 5 Proportion of participants who used the nearest designed screening centre Distance to the nearest DSC, km Rural urban categories, % Montreal Island Montreal suburbs Midsize cities* Small cities Rural areas < to < to < to < to < Overall *Midsize city areas: Quebec City, Sherbrooke, Trois-Rivières, Saguenay and Ottawa-Hull (only the portion located in the province of Quebec). Frequencies lower than 100 individuals. DSC, designated screening centres. Screening Programme could also partly account for the low participation rates observed in Montreal Island. We observed that the proportion of participants who used the nearest DSC varied according to rural urban classification and distance. The lowest proportion was seen among participants who were living in Montreal Island, possibly reflecting a greater choice of DSCs at close proximity. Women might have selected a DSC on criteria such as appointment times, 23 convenient parking 29 or accessibility by public transportation As the population and the number of DSC decreased, in the Montreal suburbs, midsize and small cities, the proportion of participants who used the nearest DSC increased. Although the likelihood of using the nearest DSC decreased with increasing distance in all rural urban categories, the highest impact was observed among participants living in rural areas. Beyond a distance of 12.5 km, the proportion that used the nearest DSC fell sharply from 90% to 50% for distances of 50.0 km and more. If women have to travel a long distance to reach the nearest DSC, they might get their mammography closer to places where they frequently travel to or at a DSC that is closer to their workplace rather than to their residence This study has strengths and limitations. The estimation of distance was derived from the exact street address of a women s residence to the exact location of the nearest DSC, which allowed precise measures. Furthermore, analyses were performed using practically the whole target population, which minimises selection bias. However, because of the large size of the population, marginal differences in participation rates reach statistical significance although that might not be of public health significance. Socioeconomic data were not available at the individual level, thus, an ecological proxy had to be used. No information was available on the use of mammography clinics outside from the Quebec Breast Cancer Screening Programme. Mammography facilities in surrounding provinces may have provided services to women residing near province borders. Our results show that distance affects participation of women to the Quebec Breast Cancer Screening Programme. The impact of distance varies according to rural urban classification except in Montreal Island. Among women who participated in the screening programme, the proportion using the nearest DSC also varies according to distance and rural urban classification. The lowest participation rates and lowest proportion of participants who used the nearest DSC are observed in Montreal Island. This represents a major issue since the metropolitan area of Montreal represents nearly half of the population of the province of Quebec. Future research should consider other dimensions of accessibility such as factors related to the capacity of a facility to accommodate demand. What is already known on the topic? Geographic accessibility has been reported as a determinant of participation in breast cancer screening, with lower participation in areas further away from screening centres. Studies estimating differences in mammography use between rural and urban women provided inconsistent results. To the best of our knowledge, no studies have reported on the modifying effect of rural urban classification on the impact of distance on participation in mammography screening. What this paper adds? The impact of distance on a women s participation in breast cancer screening is modified by the rural-urban classification. The lowest participation occurred in the metropolitan area of Montreal. Women who lived in rural areas were less sensitive to distance than their urban counterparts. Among participants, the proportion of women who used the screening centre nearest from their home varied with rural urban classification and the distance. Contributors All authors (SS-J, MDP, AL, J-MD, ÉP, DM and JB) mentioned here have contributed to conception of the study, the acquisition of data, the analysis or the interpretation of data. Moreover, all of them revised and gave final approval of the version to be published. Competing interests None. Provenance and peer review Not commissioned; externally peer reviewed. REFERENCES 1 Gøtzsche PC, Nielsen M. Screening for breast cancer with mammography (Review). Cochrane Database of Systematic Reviews 2011, Issue 1. Art. No.: CD Ministère de la Santé et des services sociaux. ed. Programme québécois de dépistage du cancer du sein (PQDCS). Cadre de référence, 1999; F:73. 3 Brustrom JE, Hunter MDC. Going the distance: how far will women travel to undergo free mammography? Mil Med 2001;166: Bulliard J-L, de Landtsheer J-P, Levi F. Profile of women not attending in the Swiss Mammography Screening Pilot Programme. Breast 2004;13: Engelman KK, Hawley DB, Gazaway R, et al. Impact of geographic barriers on the utilization of mammograms by older rural women. J Am Geriatr Soc 2002;50: Hurley SF, Huggins RM, Jolley DJ, et al. Recruitment activities and sociodemographic factors that predict attendance at a mammographic screening programme. Am J Public Health 1994;84: Hyndman JCG, Holman CDJ, Dawes VP. Effect of distance and social disadvantage on the response to invitations to attend mammography screening. J Med Screen 2000;7: Maheswaran R, Pearson T, Jordan H, et al. Socioeconomic deprivation, travel distance, location of service, and uptake of breast cancer screening in North Derbyshire, UK. J Epidemiol Community Health 2006;60: St-Jacques S, et al. J Epidemiol Community Health 2013;0:1 7. doi: /jech

7 9 Maxwell A. Relocation of a static breast screening unit: a study of factors affecting attendance. J Med Screen 2000;7: Jackson MC, Davis WW, Waldron W, et al. Impact of geography on mammography use in California. Cancer Causes Control 2009;20: Meersman SC, Breen N, Pickle LW, et al. Access to mammography screening is a large urban population: a multi-level analysis. Cancer Causes Control 2009;20: Bryant H, Mah Z. Breast cancer screennig attitudes and behaviors of rural and urban women. Prev Med 1992;21: Coughlin SS, Thompson TD, Hall HI, et al. Breast and cervical carcinoma screening practices among women in rural and nonrural areas of the United States. Cancer 2002;94: Doescher MP, Jackson JE. Trends in cervical and breast cancer screening practices among women in rural and urban areas of the United States. J Public Health Manag Pract 2009;15: Bulliard J-L, de Landtsheer J-P, Levi F. Fidélisation aux programmes de dépistage du cancer du sein en Suisse: rôle central du médecin. Praxis 2005;94: O Byrne A-M, Kavanagh AM, Ugoni A, et al. Predictors of non-attendance for second round mammography in an Australian mammographic screening programme. J Med Screen 2000;7: Statistics Canada. Census dictionary Schueler KM, Chu PW, Smith-Bindman R. Factors associated with mammography utilization: a systematic quantitative review of the literature. J Womens Health 2008;17: Pampalon R, Hamel D, Gamache P, et al. A deprivation index for health planning in Canada. Chronic Dis Can 2009;29: Statistics Canada Census dictionary X. p Wacholder S. Binomial regression in GLIM: estimating risk ratios and risk differences. Am J Epidemiol 1986;123: Peipins LA, Graham S, Young R, et al. Time and distance barriers to mammography facilities in the Atlanta metropolitan area. J Community Health 2011;36(4): Richardson A. Factor likely to affect participation in mammographic screening. NZ Med J 1990;103: Lamarche PA, Pampalon R, Haggerty J, et al. The experience of primary health care users: a rural-urban paradox. Can J Rural Med 2010;15: Statistic Canada. Immigration in Canada: a portrait of the foreing-born population_2006 census. Ottawa: Government of Canada, 2007: Shields M, Wilkins K. An update on mammography use in Canada Research article., in Health Reports. Statistics Canada. Catalogue no XPE. 2009, 20(3). Health Reports. 27 Swan J, Breen N, Coates RJ, et al. Progress in cancer screening practices in the United States. Results from the 2000 National Health Interview Survey. Cancer 2003;97: Glazier RH, Creatore MI, Gozdyra P, et al. Geographic methods for understanding and responding to disparities in mammography use in Toronto, Canada. J Gen Intern Med 2004;19: Linsell L, Forbes LJL, Patnick J, et al. Women s preferences for the delivery of the National Health Service Breast Screening Programme: a cross-sectional survey. J Med Screen 2010;17: Kreher NE, Hickner JM, Ruffin MT, et al. Effect of distance and travel time on rural women s compliance with screening mammography: An UPRNet study. Fam Pract 1995;40: Stark CR, Reay L, Shiroyama C. The effect of access factors on breast screening attendance on two Scottish islands. Health Bull 1997;55: Rahman S, Price JH, Dignan M, et al. Access to mammography facilities and detection of breast cancer by screening mammography: a GIS approach. Int J Canc Prev 2009;2: St-Jacques S, et al. J Epidemiol Community Health 2013;0:1 7. doi: /jech