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Attenders and non-attenders at a breast screening clinic: a comparative study
Public Health (1988), 102, 3-10
A t t e n d e r s and N o n - a t t e n d e r s at a B r e a s t S c r e e n i n g Clinic: a C o m p a r a t i v e S t u d y Sonja M. Hunt
Research Unit in Hea/th and Behavioura/ Change, University of Edinburgh, 17 Teviot P/ace, Edinburgh EH1 2QZ Freda Alexander
Medica/ Computing and Statistics, University of Edinburgh M. Maureen Roberts
Breast Screening C/inic, Springwefl House, Ardmi//an Terrace, Edinburgh
As part of the trial for assessing the value of breast screening, all women in the Edinburgh area who became eligible for screening over a nine-month period were sent a standard questionnaire of perceived health status. Results were analysed in the light of subsequent attendance or non-attendance at the clinic. Of those women who replied to the questionnaire, attenders at the clinic, those who did not respond to the questionnaire and those who declined the questionnaire were found to have a similar perceived health status, close to the population norm for this age and sex; those who accepted the invitation but failed to attend reported more health problems overall and these were statistically significant for emotional distress, social isolation and sleep problems. These differences were independent of postal code sector. It is suggested that more attention be paid to the heterogeneity of non-attenders for screening and the social and emotional context within which an invitation for screening is received and accepted. The current medical view o f screening for breast cancer as a feasible a n d desirable preventative procedure has d r a w n attention to those w o m e n w h o do not take a d v a n t a g e o f the proferred services. Several studies have c o m p a r e d 'attenders' and ' n o n - a t t e n d e r s ' in terms o f demographic, social, psychological and health characteristics, with rather a m b i g u o u s results. In general, it appears that w o m e n w h o accept an invitation for breast screening are m o r e likely to make use o f other preventative measures than are non-acceptors, and they tend to be y o u n g e r and m o r e affluent, with participation being higher in the middle classes than at the extremes o f the social scale.~ Some n o n - a c c e p t o r s have been f o u n d to react to an invitation to a breast screening clinic with fear a n d w o r r y that they will be f o u n d to have a problem, whilst other w o m e n regarded screening as unnecessary because they perceived their health to be very good. 2"3'4Conversely, in other studies, w o m e n who rate their health as g o o d or very g o o d have been f o u n d to be m o r e likely to attend for breast screening than those w h o regard their health as poor, very p o o r or fair. 5 Attenders, however, have also been reported to feel themselves to be m o r e vulnerable to breast cancer. 6 Psychiatric morbidity is said n o t to differ significantly between attenders a n d non-attenders, 7 although attenders have been f o u n d to be m o r e 'socially integrated, 2'8 a finding which m a y well be related to age and social class. W o m e n in p o o r physical health a n d / o r with some disability have been reported as being b o t h m o r e and less likely to participate in preventative p r o g r a m m e s in g e n e r a l Y ° O The Society of Community Medicine, 1988
4
S . M . Hunt, F. Alexander a n d M . M. Roberts
It seems probable that the general labels of 'attenders' and 'non-attenders' hide subgroups who may differ from each other considerably in demographic, social, emotional and physical characteristics. Most studies, moreover, have been based on rather small samples and have involved post hoc definitions of attendance or non-attendance for screening. The comparative perceived health status, both mental and physical, o f attenders and nonattenders has received little attention, yet may play a crucial role in decisions about visiting a clinic. Utilisation o f most types of health service depends primarily upon the perceived needs of the clientele and, as the Griffiths report pointed out, the future efficiency o f health services may well depend upon the adoption of a 'needs derived' approach rather than upon the assumption ofneed.~l The same report emphasises that perceived need plays a significant role in the efficacy and delivery o f services at a local level and is of inestimable value in planning for patterns of health care and resource allocation. Perceived need for services has been shown to be closely related to perceived health ~2and some assessment of this in invitees for screening would cast much needed light upon reasons underlying attendance or non-attendance. Self-perceived health has received a great deal of attention in recent years. It has been found to be predictive of mortality; ~3to be a key factor in adjustment to major episodes of illness;~4 and to be closely related to consultation or non-consultation of general practitioners. 15 The assessment of health by self-report requires a reliable and fully validated instrument. One such instrument is the Nottingham Health Profile which measures self-perceived problems relating to physical, psychological and social distress. It has been extensively tested for reliability and validity under a variety of conditions ranging from clinical trials to community surveys, and is suitable both as an outcome measure and for the description of general patterns of self-perceived health statusJ 6'~7Since its development it has been used successfully in a variety of studies ranging from the costs and benefits of heart transplantation, ~s through rehabilitation after stroke, ~9to comparisons of unemployed and employed men. 20 The Profile consists of 38 items which tap 6 areas of experience: energy, emotional reactions, social isolation, sleep, pain and physical mobility. Within the 6 sections items are weighted in terms of their perceived severity and the weights total 100. Thus, the higher the score on any one section the greater is the respondent's perceived distress. One o f the advantages of this instrument is that population values based upon aggregated data from several large surveys are available by age and sex for comparison purposes. 2~ Method
As part o f the trial for assessing the value o f screening for breast cancer by mammography and clinical examination, 22 all women in the Edinburgh area who are registered with participating general practitioners are brought into the trial when they reach age 45 years. In addition, newcomers to a practice are also entered. During the period 16 January 1985 to 21 October 1985, all women newly entered to the trial and eligible for screening were sent a copy o f the Nottingham Health Profile, a covering letter and a pre-paid envelope timed to arrive ten days after the invitation for screening and well before the proposed date o f their attendance at the clinic. Confidentiality was ensured, but participants were identifiable by code number in order that information from the trial data base could be added, namely screening attendance data and age. Since the majority of women are in the age group 4 5 - 4 9 years and the number o f new entrants outside this was very small, the analysis is confined to this age range.
Attenders and Non-attenders at a Breast Screening Clinic
5
By matching code numbers, it was possible to group the sample in terms of those who did reply to the questionnaire and those who did not reply and by the five categories o f response to the invitation for breast screening, i.e. 'attended the clinic', 'did not respond', 'declined the invitation', 'accepted the invitation but did not attend (DNA)', 'returned post by GPO'. As there were only 5 in this latter category who replied to the questionnaire it was omitted from the analysis. The sample was grouped into somewhat arbitrary categories by postal code sector prior to analysis. However, these categories were based upon well accepted social indicators used by Lothian Regional Council and drawn from Census data. Dissatisfaction with classification by occupation, especially for women, has led to interest in small area analysis. The advantage of classifying data by such areas is that they tend to be homogeneous socio-demographically and can thus highlight characteristic variables which may be related to health and behaviour. Several studies have demonstrated the heuristic value of small area analysis. 23'24'25 The categories chosen here were: (1) Areas characterised by low income local authority housing estates, higher than average levels of unemployment and low car ownership. (2) Areas characterised by better quality local authority housing, average levels of unemployment, middle income tenements and privately owned housing, average car ownership. (3) Areas characterised by high income private housing, lower than average unemployment and high levels o f car ownership. Data analysis
Tables II and III have been analysed using ordinary chi-squared tests and log linear analysis. As the distributions of weighted scores on the Nottingham Health Profile were very skew with large numbers o f zero scores (i.e. women answering 'no' to every item), parametric statistics were not appropriate. Kruskal-Wallis and Mann Whitney U tests are, therefore, used throughout. Results
Table I summarises the details of reply to the questionnaire.
Table I
Reply to the questionnaire
Total questionnaires sent Returned gone away Returned deceased
2,223 200 1
Probable recipients Returned refused Returned incomplete No reply
2,022 10 7 552
Usable questionnaires
1,453
True reply rate 72.5%
6
S . M . Hunt, F. Alexander and M. M. Roberts Table II
Attendance at the clinic and Post Code Category of Residence
Attended No response Declined *DNA
Post Code Category 1 % (n = 397)
Post Code Category 2 % (n = 608)
Post Code Category 3 % (n = 421)
69 17 I1 3
79 12 8 1
76 12 10 2
* Accepted the invitation but did not attend for screening.
A n analysis o f attendance at the clinic by Post C o d e C a t e g o r y o f Residence is shown in Table II. This shows the total n u m b e r o f w o m e n invited for screening with the exception o f 165 w o m e n whose area o f residence could not be categorised because o f geographical scatter. The differences are statistically significant ( ~ = 15.21, d.f. = 6) and indicate higher attendance rates and lower no response rates from the high and middle income areas as c o m p a r e d to the lower income areas. As expected, w o m e n who attended for screening had the highest reply rate to the questionnaire. The difference between reply rate for 'attenders' and all ' n o n - a t t e n d e r s ' is statistically significant ( P < 0 . 0 0 1 ) and this difference is particularly evident in the low income areas (Post Code C a t e g o r y l) as shown in Table III. There were also marked differences within the ' n o n - a t t e n d e r ' category. W o m e n who declined the invitation to the clinic were m o r e likely to return the questionnaire than those who did not respond to the invitation at all. Those who accepted the invitation but who did not attend were least likely to return the questionnaire if they lived in the high income area.
Table ilI
Questionnaire response by four categories of response to the screening invitation
Response to invitation
n
Post Code Category 1
Attended No response Declined DNA
1,206 211 145 29
86 21 49 73
Questionnaire reply rate (%) Post Code Post Code Category 2 Category 3 85 30 68 50
77 30 74 37.5
Overall 83 25 59 55
GLIM analysis: Logistic regression, effect of screening response ~ = 31.56, P < 0.001. Interaction of area with attendance categories X = 9.77, P < 0.025.
Nottingham Health Profile ( N H P ) Figure 1 shows the p r o p o r t i o n o f zero scorers on each section o f the N H P by four kinds o f response to screening (with 95% confidence intervals), and gives p o p u l a t i o n values, This
Attenders and Non-attenders at a Breast Screening Clinic
7
~) 100~-
Ii
I!I .~
I +
70
t i i
!
a_
60
-r z m .g2
I
)~ I : __x__~_~_
I I
ii
i i i
I
x
i
1 I
~x
X
i
50-
r i
g 3o
--(j
x
°a 2o
0
- L ~
Fnergy
i
I
I
I
F
Emotional reactions
l
I_
I
I
Social isolation
I
I
I
Sleep
I
I
I ~
Pain
I
I
I
Physical mobility
l--
Figure 1 Proportion of women having zero scores on every section of the NHP for four types of response to the screening invitation, showing 95% confidence limits and population values. Attenders , non-responders , decliners - - - - --., did not attend . . . . . . . . .
indicates that 'attenders', those who declined an invitation and those who did not respond are very similar in the low proportion o f each reporting any health problem. The group o f women who accepted an invitation and subsequently did not attend, however, contains fewer people with zero scores on every section of the NHP. Comparison of the proportion of zero scorers in each category with population percentages for women in this age group shows that 'attenders', 'decliners' and 'non-responders' cluster around the average in all sections. The D N A group again have fewer zero scorers, i.e. a higher proportion of women reporting at least one health problem, than do an 'average' group of women. This differerLce from population values attains statistical significance on emotional reactions, sleep and social isolation. Table IV shows a comparison o f weighted scores for attenders, three categories o f nonattenders and population values. Because of the high number o f zero scores the median is equal to zero in almost all cases. In order to illustrate differences, therefore, we show scores at the 85th percentile. Differences achieved statistical significance (Kruskal-Wallis test P < 0 . 0 5 ) on social isolation, sleep and emotional reactions. As the Table indicates, 'attenders', 'decliners' and 'non-responders' were very similar to each other and to the population norm, except that 'decliners' contained very few women who had any social isolation problem, in contrast to 'attenders', 'non-responders' and the 'norm'. Those women who accepted an invitation and did not attend, had higher scores on every section of the NHP. These analyses were repeated for the three post code categories and it was confirmed that the same pattern held in each.
S. M. Hunt, F. Alexander and M. M. Roberts
8 Table IV
Scores at the 85th percentile on each section of the NHP for attenders and 3 categories of non-attenders and the population value Attenders
Energy Emotional reactions Social isolation Sleep Pain Physical mobility
Declined No response
DNA
Population value
(P)
38.4
38.3
61.8
62.2
39.2
(0.5)
28.4
28.0
42.5
55.9
27.45
(0.054)
16.3 33.7 9.3
0.0 30.1 10.8
1.9 51.7 15.0
31.5 73.3 18.9
15.97 28.67 12.91
(0.02) (0.004) (0.6)
10.9
11.0
10.6
21.5
11.54
(0.2)
Discussion
Most previous studies of response to screening have treated non-attenders as a single group whose primary characteristic is low socio-economic status. This study confirms that the highest response does come from higher income areas, but also indicates that within different socio-demographic groupings different categories of non-attenders have different characteristics. W o m e n who returned the questionnaire and actively declined the invitation perceived themselves to be in very good health. Those who did not respond at all to an invitation, but did reply to the questionnaire, were less likely to live in a higher income area but had a perceived health status similar to that o f the attenders, except that they reported more sleep problems. Those women who accepted an invitation but failed to attend the clinic ( D N A group) were more likely to live in a low income area. O f this D N A group, those living in low income areas were more likely to reply to the questionnaire. O f all the women who replied to the questionnaire the D N A group were more likely to report health problems, particularly of sleep and social isolation. These latter differences were statistically significant and persisted after allowing for post code category. It seems likely that non-attenders for breast screening form a heterogeneous group whose reasons for non-attendance are quite diverse. Those who decline the invitation but complete the questionnaire may consider screening unnecessary as they feel particularly well. Alternatively they may have doubts about its efficacy. W o m e n who do not attend subsequent to accepting the invitation m a y be under considerable strain from their social circumstances. Other studies have suggested that women living in adverse conditions, where sudden crises are likely to arise and social and financial resources are limited, m a y find it difficult to keep appointments. 26 For example, someone in the family falls ill, or money for fares is not available that day. It is also possible that the pre-existing emotional upset of the w o m e n who do not attend is exacerbated as the time of the appointment draws nearer and they became too upset to keep the appointment. A previous study found that although some working class women accept the case for attendance for screening at an intellectual level, they reject it for emotional reasons related to the possibility o f personal vulnerability, 27and it m a y be that this is also reflected in the findings presented here. It should be noted, however, that they also indicate that this ambivalence, if present, is not necessarily confined to working class women. Since the reply rate to the questionnaire from attenders was very high we feel justified in concluding that they represent women of a good perceived health status similar to that of the
A ttenders and Non-attenders at a Breast Screening Clinic
9
o t h e r w o m e n o f their age g r o u p in the p o p u l a t i o n . T h e d a t a f r o m the s a m p l e o f n o n a t t e n d e r s is, o f course, b i a s e d as it represents o n l y those w h o r e t u r n e d the q u e s t i o n n a i r e , a n d it is quite p o s s i b l e t h a t t h o s e w h o d i d n o t r e t u r n the q u e s t i o n n a i r e r e p r e s e n t further subg r o u p s with different characteristics. W e suggest t h a t a focus on s o c i o - e c o n o m i c c h a r a c t e r i s t i c s a l o n e will hide the h e t e r o g e n e i t y o f w i t h i n - g r o u p c h a r a c t e r i s t i c s a n d we s u p p o r t the c o n t e n t i o n o f L e a t h a r & R o b e r t s t h a t m o r e a t t e n t i o n s h o u l d be p a i d to the social a n d e m o t i o n a l c o n t e x t in which a n i n v i t a t i o n for screening is received a n d a c c e p t e d , t o g e t h e r with social a n d e m o t i o n a l b a r r i e r s to a c t u a l a t t e n d a n c e . F i n a l l y , it s h o u l d be n o t e d t h a t a positive decision n o t to a t t e n d m a y well be a r a t i o n a l r e s p o n s e b y an e x c e p t i o n a l l y h e a l t h y a n d e c o n o m i c a l l y privileged g r o u p o f w o m e n .
References 1. Van Den Heuvel, W.J, A. (1978). Participants and non-participants in a mammography mass screening. Who is who? In Breast Cancer. Brand, P. C. and Keep, P. A. (cds). p. 91 96. London: MTP Press. 2. Maclean, U., Sinfield, D., Klein, S. & Harnden, B. (1984). Women who decline breast screening. Journal of Epidemiology and Community Health, 38, 278-283. 3. French, K., Porter, A. M. D., Robinson, S. E,, McCallum, F., Howie, J. G. R. & Roberts, M. M. (1982). Attendance at a breast screening clinic: a problem of administration or attitudes? British Medical Journal, 225, 617-620. 4. Hobbs, P., Smith, A., George, W, D. & Sellwood, R.A. (1980). Acceptors and rejectors of an invitation to undergo breast screening compared with those who refer themselves. Journal c~/" Epidemiology and Community Health, 34, 19-22. 5. Calnan, M. (1984). The Health Belief Model and participation in programmes for the early detection of breast cancer: a comparative analysis. Social Science and Medicine, 19, 823-830. 6. Fink, R., Shapiro, S. & Lewis, R. (1968). The reluctant participant in a breast screening programme. Public Health Reports, 83, 479-485. 7. Dean, C., Roberts, M. M., French, K. & Robinson, S. (1986). Psychiatric morbidity after screening for breast cancer. Journal of Epidemiology and Community Health, 40, 7 l - 75. 8. Langlie, J. K. (1977). Social networks, health beliefs and preventive health behaviour. Journal of Health and Social Behaviour, 18, 244 286. 9. Schwoon, D. R. & Schmoll, J. H. (1979). Motivation to participate in cancer screening programmes. Social Science and Medicine, 13A, 283-286. 10. Calnan, M. (1985). Patterns in preventive behaviour: a study of women in middle age. Social Science and Medicine, 3, 263 268. 11. Griffiths, E. R. (1983). Report qfthe NHS Management Enquiry. London: HMSO. 12. Becker, M. & Maiman, L. A. (1983). Models of health related behaviour. In Handbook of Health, Health Care and the Health Professions. Mechanic, D. (ed). p. 539 568. New York: The Free Press. 13. Singer, E., Garfinkel, R., Cohen, S. M. & Srole, L. (1976). Mortality and mental health: evidence from the Midtown Manhattan Re-study. Social Science and Medicine, 10, 517 521. 14. National Heart and Lung Institute (1976). Proceedings of the Heart and Lung Institute Working Conference on Health Behaviour. Weiss, S. M. (ed). Pub. No. (NIH) 76 868. New York, DHEW. 15. Hunt, S. M., McKenna, S. P. & McEwen, J. (1981). The Nottingham Health Profile: subjective health status and medical consultations. Social Science and Medicine, 15A, 221-229. 16. Hunt, S. M., McEwen, J. & McKenna, S. P. (1985). Measuring Health Status: a new tool for clinicians and epidemiologists. Journal of the Royal College of General Practitioners, 35, 185-188. 17. Hunt, S. M., McEwen, J. & McKenna, S.P. (1986). Measuring Health Status. London: Croom Helm. 18. Department of Health and Social Security (1985). Costs and benefits of the heart transplant programme at Harefield and Papworth Hospitals. London: HMSO.
10
S. M. Hunt, F. Alexander and M. M. Roberts
19. Ebrahim, S., Barer, D. & Nouri, F. (1986). Use of the Nottingham Health Profile with patients after a stroke. Journal of Epidemiology and Community Health, 40, 166-169. 20. McKenna, S. P. & Fryer, D. (1984). Perceived health during lay off and early unemployment. Occupational Health, May, 201-206. 21. Hunt, Sonja, M. (1985). Nottingham Health Profile: User's Manual. Mimeo. 22. Roberts, M. M., Alexander, F. E., Anderson, T. J., Forrest, A. P. M., Hepburn, W., Huggins, A., Kirkpatrick, A. E., Lamb, J., Lutz, W. & Muir, B. B. (1984). The Edinburgh randomised trial of screening for breast cancer. British Journal of Cancer, 18, 791-797. 23. Carstairs, V. (1981). Small area analysis and health services research. Community Medicine, 3, 131-139. 24. Dyer, J., Farmer, J., Harvey, P. W. & Roberts, J. (1978). The demands made on emergency room facilities by an urban population. Public Health, 92, 78-83. 25. Madeley, R. (1978). Relating child health services to needs by the use of simple epidemiology. Public Health, 92, 224-230. 26. McKinlay, J. B. (1972). Some approaches and problems in the study of the use of services: an overview. Journal of Health and Social Behaviour, 13, 115 - 152. 27. Leathar, D. S. & Roberts, M. M. (1985). Older women's attitudes towards breast disease, self examination and screening facilities: implications for communication. British Medical Journal, 290, 668-670.
A t t e n d e r s and N o n - a t t e n d e r s at a B r e a s t S c r e e n i n g Clinic: a C o m p a r a t i v e S t u d y Sonja M. Hunt
Research Unit in Hea/th and Behavioura/ Change, University of Edinburgh, 17 Teviot P/ace, Edinburgh EH1 2QZ Freda Alexander
Medica/ Computing and Statistics, University of Edinburgh M. Maureen Roberts
Breast Screening C/inic, Springwefl House, Ardmi//an Terrace, Edinburgh
As part of the trial for assessing the value of breast screening, all women in the Edinburgh area who became eligible for screening over a nine-month period were sent a standard questionnaire of perceived health status. Results were analysed in the light of subsequent attendance or non-attendance at the clinic. Of those women who replied to the questionnaire, attenders at the clinic, those who did not respond to the questionnaire and those who declined the questionnaire were found to have a similar perceived health status, close to the population norm for this age and sex; those who accepted the invitation but failed to attend reported more health problems overall and these were statistically significant for emotional distress, social isolation and sleep problems. These differences were independent of postal code sector. It is suggested that more attention be paid to the heterogeneity of non-attenders for screening and the social and emotional context within which an invitation for screening is received and accepted. The current medical view o f screening for breast cancer as a feasible a n d desirable preventative procedure has d r a w n attention to those w o m e n w h o do not take a d v a n t a g e o f the proferred services. Several studies have c o m p a r e d 'attenders' and ' n o n - a t t e n d e r s ' in terms o f demographic, social, psychological and health characteristics, with rather a m b i g u o u s results. In general, it appears that w o m e n w h o accept an invitation for breast screening are m o r e likely to make use o f other preventative measures than are non-acceptors, and they tend to be y o u n g e r and m o r e affluent, with participation being higher in the middle classes than at the extremes o f the social scale.~ Some n o n - a c c e p t o r s have been f o u n d to react to an invitation to a breast screening clinic with fear a n d w o r r y that they will be f o u n d to have a problem, whilst other w o m e n regarded screening as unnecessary because they perceived their health to be very good. 2"3'4Conversely, in other studies, w o m e n who rate their health as g o o d or very g o o d have been f o u n d to be m o r e likely to attend for breast screening than those w h o regard their health as poor, very p o o r or fair. 5 Attenders, however, have also been reported to feel themselves to be m o r e vulnerable to breast cancer. 6 Psychiatric morbidity is said n o t to differ significantly between attenders a n d non-attenders, 7 although attenders have been f o u n d to be m o r e 'socially integrated, 2'8 a finding which m a y well be related to age and social class. W o m e n in p o o r physical health a n d / o r with some disability have been reported as being b o t h m o r e and less likely to participate in preventative p r o g r a m m e s in g e n e r a l Y ° O The Society of Community Medicine, 1988
4
S . M . Hunt, F. Alexander a n d M . M. Roberts
It seems probable that the general labels of 'attenders' and 'non-attenders' hide subgroups who may differ from each other considerably in demographic, social, emotional and physical characteristics. Most studies, moreover, have been based on rather small samples and have involved post hoc definitions of attendance or non-attendance for screening. The comparative perceived health status, both mental and physical, o f attenders and nonattenders has received little attention, yet may play a crucial role in decisions about visiting a clinic. Utilisation o f most types of health service depends primarily upon the perceived needs of the clientele and, as the Griffiths report pointed out, the future efficiency o f health services may well depend upon the adoption of a 'needs derived' approach rather than upon the assumption ofneed.~l The same report emphasises that perceived need plays a significant role in the efficacy and delivery o f services at a local level and is of inestimable value in planning for patterns of health care and resource allocation. Perceived need for services has been shown to be closely related to perceived health ~2and some assessment of this in invitees for screening would cast much needed light upon reasons underlying attendance or non-attendance. Self-perceived health has received a great deal of attention in recent years. It has been found to be predictive of mortality; ~3to be a key factor in adjustment to major episodes of illness;~4 and to be closely related to consultation or non-consultation of general practitioners. 15 The assessment of health by self-report requires a reliable and fully validated instrument. One such instrument is the Nottingham Health Profile which measures self-perceived problems relating to physical, psychological and social distress. It has been extensively tested for reliability and validity under a variety of conditions ranging from clinical trials to community surveys, and is suitable both as an outcome measure and for the description of general patterns of self-perceived health statusJ 6'~7Since its development it has been used successfully in a variety of studies ranging from the costs and benefits of heart transplantation, ~s through rehabilitation after stroke, ~9to comparisons of unemployed and employed men. 20 The Profile consists of 38 items which tap 6 areas of experience: energy, emotional reactions, social isolation, sleep, pain and physical mobility. Within the 6 sections items are weighted in terms of their perceived severity and the weights total 100. Thus, the higher the score on any one section the greater is the respondent's perceived distress. One o f the advantages of this instrument is that population values based upon aggregated data from several large surveys are available by age and sex for comparison purposes. 2~ Method
As part o f the trial for assessing the value o f screening for breast cancer by mammography and clinical examination, 22 all women in the Edinburgh area who are registered with participating general practitioners are brought into the trial when they reach age 45 years. In addition, newcomers to a practice are also entered. During the period 16 January 1985 to 21 October 1985, all women newly entered to the trial and eligible for screening were sent a copy o f the Nottingham Health Profile, a covering letter and a pre-paid envelope timed to arrive ten days after the invitation for screening and well before the proposed date o f their attendance at the clinic. Confidentiality was ensured, but participants were identifiable by code number in order that information from the trial data base could be added, namely screening attendance data and age. Since the majority of women are in the age group 4 5 - 4 9 years and the number o f new entrants outside this was very small, the analysis is confined to this age range.
Attenders and Non-attenders at a Breast Screening Clinic
5
By matching code numbers, it was possible to group the sample in terms of those who did reply to the questionnaire and those who did not reply and by the five categories o f response to the invitation for breast screening, i.e. 'attended the clinic', 'did not respond', 'declined the invitation', 'accepted the invitation but did not attend (DNA)', 'returned post by GPO'. As there were only 5 in this latter category who replied to the questionnaire it was omitted from the analysis. The sample was grouped into somewhat arbitrary categories by postal code sector prior to analysis. However, these categories were based upon well accepted social indicators used by Lothian Regional Council and drawn from Census data. Dissatisfaction with classification by occupation, especially for women, has led to interest in small area analysis. The advantage of classifying data by such areas is that they tend to be homogeneous socio-demographically and can thus highlight characteristic variables which may be related to health and behaviour. Several studies have demonstrated the heuristic value of small area analysis. 23'24'25 The categories chosen here were: (1) Areas characterised by low income local authority housing estates, higher than average levels of unemployment and low car ownership. (2) Areas characterised by better quality local authority housing, average levels of unemployment, middle income tenements and privately owned housing, average car ownership. (3) Areas characterised by high income private housing, lower than average unemployment and high levels o f car ownership. Data analysis
Tables II and III have been analysed using ordinary chi-squared tests and log linear analysis. As the distributions of weighted scores on the Nottingham Health Profile were very skew with large numbers o f zero scores (i.e. women answering 'no' to every item), parametric statistics were not appropriate. Kruskal-Wallis and Mann Whitney U tests are, therefore, used throughout. Results
Table I summarises the details of reply to the questionnaire.
Table I
Reply to the questionnaire
Total questionnaires sent Returned gone away Returned deceased
2,223 200 1
Probable recipients Returned refused Returned incomplete No reply
2,022 10 7 552
Usable questionnaires
1,453
True reply rate 72.5%
6
S . M . Hunt, F. Alexander and M. M. Roberts Table II
Attendance at the clinic and Post Code Category of Residence
Attended No response Declined *DNA
Post Code Category 1 % (n = 397)
Post Code Category 2 % (n = 608)
Post Code Category 3 % (n = 421)
69 17 I1 3
79 12 8 1
76 12 10 2
* Accepted the invitation but did not attend for screening.
A n analysis o f attendance at the clinic by Post C o d e C a t e g o r y o f Residence is shown in Table II. This shows the total n u m b e r o f w o m e n invited for screening with the exception o f 165 w o m e n whose area o f residence could not be categorised because o f geographical scatter. The differences are statistically significant ( ~ = 15.21, d.f. = 6) and indicate higher attendance rates and lower no response rates from the high and middle income areas as c o m p a r e d to the lower income areas. As expected, w o m e n who attended for screening had the highest reply rate to the questionnaire. The difference between reply rate for 'attenders' and all ' n o n - a t t e n d e r s ' is statistically significant ( P < 0 . 0 0 1 ) and this difference is particularly evident in the low income areas (Post Code C a t e g o r y l) as shown in Table III. There were also marked differences within the ' n o n - a t t e n d e r ' category. W o m e n who declined the invitation to the clinic were m o r e likely to return the questionnaire than those who did not respond to the invitation at all. Those who accepted the invitation but who did not attend were least likely to return the questionnaire if they lived in the high income area.
Table ilI
Questionnaire response by four categories of response to the screening invitation
Response to invitation
n
Post Code Category 1
Attended No response Declined DNA
1,206 211 145 29
86 21 49 73
Questionnaire reply rate (%) Post Code Post Code Category 2 Category 3 85 30 68 50
77 30 74 37.5
Overall 83 25 59 55
GLIM analysis: Logistic regression, effect of screening response ~ = 31.56, P < 0.001. Interaction of area with attendance categories X = 9.77, P < 0.025.
Nottingham Health Profile ( N H P ) Figure 1 shows the p r o p o r t i o n o f zero scorers on each section o f the N H P by four kinds o f response to screening (with 95% confidence intervals), and gives p o p u l a t i o n values, This
Attenders and Non-attenders at a Breast Screening Clinic
7
~) 100~-
Ii
I!I .~
I +
70
t i i
!
a_
60
-r z m .g2
I
)~ I : __x__~_~_
I I
ii
i i i
I
x
i
1 I
~x
X
i
50-
r i
g 3o
--(j
x
°a 2o
0
- L ~
Fnergy
i
I
I
I
F
Emotional reactions
l
I_
I
I
Social isolation
I
I
I
Sleep
I
I
I ~
Pain
I
I
I
Physical mobility
l--
Figure 1 Proportion of women having zero scores on every section of the NHP for four types of response to the screening invitation, showing 95% confidence limits and population values. Attenders , non-responders , decliners - - - - --., did not attend . . . . . . . . .
indicates that 'attenders', those who declined an invitation and those who did not respond are very similar in the low proportion o f each reporting any health problem. The group o f women who accepted an invitation and subsequently did not attend, however, contains fewer people with zero scores on every section of the NHP. Comparison of the proportion of zero scorers in each category with population percentages for women in this age group shows that 'attenders', 'decliners' and 'non-responders' cluster around the average in all sections. The D N A group again have fewer zero scorers, i.e. a higher proportion of women reporting at least one health problem, than do an 'average' group of women. This differerLce from population values attains statistical significance on emotional reactions, sleep and social isolation. Table IV shows a comparison o f weighted scores for attenders, three categories o f nonattenders and population values. Because of the high number o f zero scores the median is equal to zero in almost all cases. In order to illustrate differences, therefore, we show scores at the 85th percentile. Differences achieved statistical significance (Kruskal-Wallis test P < 0 . 0 5 ) on social isolation, sleep and emotional reactions. As the Table indicates, 'attenders', 'decliners' and 'non-responders' were very similar to each other and to the population norm, except that 'decliners' contained very few women who had any social isolation problem, in contrast to 'attenders', 'non-responders' and the 'norm'. Those women who accepted an invitation and did not attend, had higher scores on every section of the NHP. These analyses were repeated for the three post code categories and it was confirmed that the same pattern held in each.
S. M. Hunt, F. Alexander and M. M. Roberts
8 Table IV
Scores at the 85th percentile on each section of the NHP for attenders and 3 categories of non-attenders and the population value Attenders
Energy Emotional reactions Social isolation Sleep Pain Physical mobility
Declined No response
DNA
Population value
(P)
38.4
38.3
61.8
62.2
39.2
(0.5)
28.4
28.0
42.5
55.9
27.45
(0.054)
16.3 33.7 9.3
0.0 30.1 10.8
1.9 51.7 15.0
31.5 73.3 18.9
15.97 28.67 12.91
(0.02) (0.004) (0.6)
10.9
11.0
10.6
21.5
11.54
(0.2)
Discussion
Most previous studies of response to screening have treated non-attenders as a single group whose primary characteristic is low socio-economic status. This study confirms that the highest response does come from higher income areas, but also indicates that within different socio-demographic groupings different categories of non-attenders have different characteristics. W o m e n who returned the questionnaire and actively declined the invitation perceived themselves to be in very good health. Those who did not respond at all to an invitation, but did reply to the questionnaire, were less likely to live in a higher income area but had a perceived health status similar to that o f the attenders, except that they reported more sleep problems. Those women who accepted an invitation but failed to attend the clinic ( D N A group) were more likely to live in a low income area. O f this D N A group, those living in low income areas were more likely to reply to the questionnaire. O f all the women who replied to the questionnaire the D N A group were more likely to report health problems, particularly of sleep and social isolation. These latter differences were statistically significant and persisted after allowing for post code category. It seems likely that non-attenders for breast screening form a heterogeneous group whose reasons for non-attendance are quite diverse. Those who decline the invitation but complete the questionnaire may consider screening unnecessary as they feel particularly well. Alternatively they may have doubts about its efficacy. W o m e n who do not attend subsequent to accepting the invitation m a y be under considerable strain from their social circumstances. Other studies have suggested that women living in adverse conditions, where sudden crises are likely to arise and social and financial resources are limited, m a y find it difficult to keep appointments. 26 For example, someone in the family falls ill, or money for fares is not available that day. It is also possible that the pre-existing emotional upset of the w o m e n who do not attend is exacerbated as the time of the appointment draws nearer and they became too upset to keep the appointment. A previous study found that although some working class women accept the case for attendance for screening at an intellectual level, they reject it for emotional reasons related to the possibility o f personal vulnerability, 27and it m a y be that this is also reflected in the findings presented here. It should be noted, however, that they also indicate that this ambivalence, if present, is not necessarily confined to working class women. Since the reply rate to the questionnaire from attenders was very high we feel justified in concluding that they represent women of a good perceived health status similar to that of the
A ttenders and Non-attenders at a Breast Screening Clinic
9
o t h e r w o m e n o f their age g r o u p in the p o p u l a t i o n . T h e d a t a f r o m the s a m p l e o f n o n a t t e n d e r s is, o f course, b i a s e d as it represents o n l y those w h o r e t u r n e d the q u e s t i o n n a i r e , a n d it is quite p o s s i b l e t h a t t h o s e w h o d i d n o t r e t u r n the q u e s t i o n n a i r e r e p r e s e n t further subg r o u p s with different characteristics. W e suggest t h a t a focus on s o c i o - e c o n o m i c c h a r a c t e r i s t i c s a l o n e will hide the h e t e r o g e n e i t y o f w i t h i n - g r o u p c h a r a c t e r i s t i c s a n d we s u p p o r t the c o n t e n t i o n o f L e a t h a r & R o b e r t s t h a t m o r e a t t e n t i o n s h o u l d be p a i d to the social a n d e m o t i o n a l c o n t e x t in which a n i n v i t a t i o n for screening is received a n d a c c e p t e d , t o g e t h e r with social a n d e m o t i o n a l b a r r i e r s to a c t u a l a t t e n d a n c e . F i n a l l y , it s h o u l d be n o t e d t h a t a positive decision n o t to a t t e n d m a y well be a r a t i o n a l r e s p o n s e b y an e x c e p t i o n a l l y h e a l t h y a n d e c o n o m i c a l l y privileged g r o u p o f w o m e n .
References 1. Van Den Heuvel, W.J, A. (1978). Participants and non-participants in a mammography mass screening. Who is who? In Breast Cancer. Brand, P. C. and Keep, P. A. (cds). p. 91 96. London: MTP Press. 2. Maclean, U., Sinfield, D., Klein, S. & Harnden, B. (1984). Women who decline breast screening. Journal of Epidemiology and Community Health, 38, 278-283. 3. French, K., Porter, A. M. D., Robinson, S. E,, McCallum, F., Howie, J. G. R. & Roberts, M. M. (1982). Attendance at a breast screening clinic: a problem of administration or attitudes? British Medical Journal, 225, 617-620. 4. Hobbs, P., Smith, A., George, W, D. & Sellwood, R.A. (1980). Acceptors and rejectors of an invitation to undergo breast screening compared with those who refer themselves. Journal c~/" Epidemiology and Community Health, 34, 19-22. 5. Calnan, M. (1984). The Health Belief Model and participation in programmes for the early detection of breast cancer: a comparative analysis. Social Science and Medicine, 19, 823-830. 6. Fink, R., Shapiro, S. & Lewis, R. (1968). The reluctant participant in a breast screening programme. Public Health Reports, 83, 479-485. 7. Dean, C., Roberts, M. M., French, K. & Robinson, S. (1986). Psychiatric morbidity after screening for breast cancer. Journal of Epidemiology and Community Health, 40, 7 l - 75. 8. Langlie, J. K. (1977). Social networks, health beliefs and preventive health behaviour. Journal of Health and Social Behaviour, 18, 244 286. 9. Schwoon, D. R. & Schmoll, J. H. (1979). Motivation to participate in cancer screening programmes. Social Science and Medicine, 13A, 283-286. 10. Calnan, M. (1985). Patterns in preventive behaviour: a study of women in middle age. Social Science and Medicine, 3, 263 268. 11. Griffiths, E. R. (1983). Report qfthe NHS Management Enquiry. London: HMSO. 12. Becker, M. & Maiman, L. A. (1983). Models of health related behaviour. In Handbook of Health, Health Care and the Health Professions. Mechanic, D. (ed). p. 539 568. New York: The Free Press. 13. Singer, E., Garfinkel, R., Cohen, S. M. & Srole, L. (1976). Mortality and mental health: evidence from the Midtown Manhattan Re-study. Social Science and Medicine, 10, 517 521. 14. National Heart and Lung Institute (1976). Proceedings of the Heart and Lung Institute Working Conference on Health Behaviour. Weiss, S. M. (ed). Pub. No. (NIH) 76 868. New York, DHEW. 15. Hunt, S. M., McKenna, S. P. & McEwen, J. (1981). The Nottingham Health Profile: subjective health status and medical consultations. Social Science and Medicine, 15A, 221-229. 16. Hunt, S. M., McEwen, J. & McKenna, S. P. (1985). Measuring Health Status: a new tool for clinicians and epidemiologists. Journal of the Royal College of General Practitioners, 35, 185-188. 17. Hunt, S. M., McEwen, J. & McKenna, S.P. (1986). Measuring Health Status. London: Croom Helm. 18. Department of Health and Social Security (1985). Costs and benefits of the heart transplant programme at Harefield and Papworth Hospitals. London: HMSO.
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S. M. Hunt, F. Alexander and M. M. Roberts
19. Ebrahim, S., Barer, D. & Nouri, F. (1986). Use of the Nottingham Health Profile with patients after a stroke. Journal of Epidemiology and Community Health, 40, 166-169. 20. McKenna, S. P. & Fryer, D. (1984). Perceived health during lay off and early unemployment. Occupational Health, May, 201-206. 21. Hunt, Sonja, M. (1985). Nottingham Health Profile: User's Manual. Mimeo. 22. Roberts, M. M., Alexander, F. E., Anderson, T. J., Forrest, A. P. M., Hepburn, W., Huggins, A., Kirkpatrick, A. E., Lamb, J., Lutz, W. & Muir, B. B. (1984). The Edinburgh randomised trial of screening for breast cancer. British Journal of Cancer, 18, 791-797. 23. Carstairs, V. (1981). Small area analysis and health services research. Community Medicine, 3, 131-139. 24. Dyer, J., Farmer, J., Harvey, P. W. & Roberts, J. (1978). The demands made on emergency room facilities by an urban population. Public Health, 92, 78-83. 25. Madeley, R. (1978). Relating child health services to needs by the use of simple epidemiology. Public Health, 92, 224-230. 26. McKinlay, J. B. (1972). Some approaches and problems in the study of the use of services: an overview. Journal of Health and Social Behaviour, 13, 115 - 152. 27. Leathar, D. S. & Roberts, M. M. (1985). Older women's attitudes towards breast disease, self examination and screening facilities: implications for communication. British Medical Journal, 290, 668-670.