- Email: [email protected]
Community perceptions about the important signs of early melanoma
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Community perceptions about the important signs of early melanoma Peter D. Baade, MedSc, Kevin P. Balanda, Phi), Warren R. Stanton, PhD, Amaya M. Gillespie, PhD, and John B. Lowe, DrPH Herston, Queensland, Australia
Background: Detecting melanoma early often relies on patient concern about a particular pigmented lesion. However, it is not clear what specific features the public views as being important. Objective: Our purpose was to explore the importance persons place on wxious features of skin lesions when looking for early signs of melanoma. Methods: This study comprised 1148 respondents (participation rate, 78%) from 60 rural communities in Queensland, Australia, who participated in a telephone interview. Results: The following features were considered important and are listed in order of importance: change in the lesion (clearly identified as the most important), more than one color, uneven edges, elevation, large size (the last three of equal importance), and hairiness of the lesion. Age, sex, education, self-efficacy, perceived knowledge, and recent self-examination influenced importance levels, but having a recent skin examination by a family physician did not.
Conclusion: To increase the skin serf-examination s~lls of the community, guidelines may have to become more specific and all opportunities fully utilized to educate the public. 0 Am Acad Dermatol 1997;36:33-9.)
Australia, in particular Queensland, has the highest reported incidence of melanoma and nonmelanoma skin cancer in the world. 1,2 Early detection offers the best oppommity to reduce mortality. 3, 4 However, international recommendations for skin seN-examination and screening for skin cancer vary considerably. 5 Several clinical criteria such as the " A B C D " rule, 6 the " A B C D E " nile, 7 and the Glasgow revised 7-point checklist 8 have been promoted to assist in the diagnosis of pigmented lesions. However, the composition of these criteria is not without controversy,6, 9 and "theyhave not been able to meet the desired level of sensitivity and specificity. 1° At least 50% of adults in Australia and overseas
From the Centre for Health Promotion and Cancer Prevention Researcl~ Medical School, University of Queensland. Support for the telephone survey was given by the Queensland Cancer Fund. Accepted for pubfication July 20, 1996. Reprint requests: Peter Baade, Centre for Health Promotion and Cancer Prevention Research, Medical School, University of Queensland, Herston Road. Herston, Queensland 4006, Australia. Copyright © 1997 by the American Academy of Dermatology, Inc. 0190-9622/97L'~5.00 + 0 16/1/76711
report that their skin is checked for early signs of skin cancer, either by themselves or with the assistance of another person or a health professional. 11-14 However, concern has been expressed about the adequacy of these reported skin checks. 11 The efficacy of skin self-examination is unknown. It has been shown that patients without melanoma can accurately report nevus counts, 15 but another study found that the public tend not to be able to identify photographs of early melanomas) 6 Thus there is some evidence that community members do not use appropriate guidelines to detect a suspect lesion and to decide whether a particular lesion warrants further attention. In addition, the public often delays in showing lesions to a physician, 17which further reduces the likelihood of a satisfactory prognosis. Possible reasons for delays in presentation may be lack of knowledge on the part of the patient, as distinct from fear or denial, 18 a perception that the lesion is not serious, 19 and the inability to see an evolving rumor. 2° This behavior has led several researchers to call for educational campaigns to increase awareness about malignant melanoma 17,2° and to inform the public about the existence of guidelines and methods in applying the criteria. 16 To design such campaigns it is first necessary to understand community per33
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Baade et al.
ceptions. However, only a few investigators have systematically studied the perceived importance placed on particular features o f skin lesions. One study found that twice as m a n y persons thought an early melanoma was raised or could be raised than those who thought it was flat. 16 The same study found that most respondents thought "darkness," " b e i n g different," or " u g l y " were c o m m o n characteristics o f melanomas. Another study found that 40% o f respondents thought an irregular outline and a mixture o f colors were characteristics of normal moles, and a third thought it was normal for moles to grow. 17 There is an urgent need for research into the process of skin serf-examination and its role in the early detection o f mafignant melanoma. 21 Cassileth et al.22 outlined four steps that lead to diagnosis of melanoma: initial awareness by the patient, suspicion or concern about that lesion, seeking medical advice, and diagnosis b y the physician. The focus of this study is the second step, specifically, to determine those features considered important signs of early melanoma b y community members.
METHODS A telephone survey of Queensland adults was conducted. The sample was drawn from 60 rural communities throughout Queensland with populations between 1000 and 4000, and it was stratified by sex. The telephone interviews were conducted with a computer-aided telephone interviewing (CATI) system in October and November 1994. Telephone numbers were randomly drawn from a list of private telephone numbers. Six attempts were made to contact potential respondents before a household was considered "noncontactable." Respondents were asked about six skin features: size (larger'than the blunt end of a pencil), change (having changed during the past 6 months), elevation (being elevated or raised), uneven edges, lesion of more than one color, and hair. The first five features were abstracted from several published skin examination guidelines, s,23 although the selection was not exhaustive. The presence of hair in a skin lesion was then included as a comparison feature. For each of these features, respondents were asked, " f f y o u were checldng your skin for early signs of skin cancer and you found a mole or spot that had (the feature), how important would you rate this on a scale of 0 to 10, where 0 is not important, and 10 is extremely important?" These six importance scores were then collapsed into three importance categories (extreme, medium, and low). The distributions of the six importance scores were similar. The shape of the distributions suggested that a score
Journal of the American Academy of Dermatology January 1997
of 5 (the midpoint of the 11-point scale) was used by respondents as an "unsure" option. A score up to 5 was thus taken to show that the respondent considered the feature either not important or of uncertain importance. There was also a concentration of scores in the higher importance levels, and the interviewer, in saying that "10 is extremely important," forced a differentiation between scores of 9 and below and 10. Therefore the three importance categories used in this analysis were as follows: extreme perceived importance (score = 10), moderate perceived importance (6---score ~< 9), and low perceived importance (0 -< score --< 5). Three attitudinal questions were included in the questionnaire: perceived knowledge of the steps involved in checking their skin ("I think I know the steps to follow to check my body for early signs of skin cancer"), perceived knowledge of features ("I think I know what features I should be looking for to check for skin cancer"), and self-efficacy ("I think I could identify something suspect on my skin"). Responses were recorded on a 5-point Likert scale ranging from "strongly agree" to "strongly disagree." For analysis, these scales were collapsed to "agree"/"not agree," with the "not sure" option included in "not agree." Details about the respondents' age (18 to 29 years, 30 to 59 years, 60 years and older), sex, and highest level of completed education were collected. Respondents were also asked whether they had checked their skin for early signs of skin cancer in the past 3 months and whether a physician had checked their skin in the past 3 months. The analysis focuses on the odds that a person will perceive a feature to be extremely important. A repeatedmeasures logistic ordinal regression model including a factor called "feature," with six levels representing each of the sldn features, was first used to estimate the odds that respondents perceived each specific skin feature to be extremely important, moderately important, or of low importance. Separate logistic ordinal regression models were then used to explore the effect of sex, age, education level, recent skin self-examination, recent skin check by a physician, knowledge of steps, knowledge of features, and self-efficacy. For each such variable, the initial base model (including "feature" only) was extended to include the variable and an interaction term (variable by feature) to assess whether its effect varied with the feature. Significance of main effects and interactions Was assessed with the chi-square statistic (X2) from these extended repeated-measures ordinal regression models.24
RESULTS W e attempted to call a total o f 2566 t e l e p h o n e numbers from the target population. O f these, 582 were ineligible and 512 households could not be contacted. The ineligible telephone numbers arose
Journal of the American Academy of Dermatology Volume 36, Number 1
Baade et aL 35
Odds 6
I Change
1 Color
Edges
l Elevated
1 Size
Hair
Feature Fig. 1. Odds of placing extreme importance (score, 10) on each of six specific features of
skin lesions when checking for early signs of skin cancer (with 95% corffidence intervals). (Results of repeated measures ordinal logistic regression.)
from business or commercial numbers or were those outside t~_e town's defined boundaries; numbers were also considered ineligible when the sex quota cells were filled. Of the eligible people contacted (n = 1472), 78% completed the telephone interview, resulting in 1148 completed interviews. Compared with the Queensland adult population, women (53.9% in sample, 50.4% in population) and those older than 40 years of age (63.7% in sample. 52.6% in population) were overrepresented in the sample. The odds ratio (OR) that change was perceived as extremely important was 4.47 (95% confidence interval [C1] = 3.85, 5.19), significantly higher than the odds that the feature more than one color was perceived as e,xtremely important (1.33; 95% CI = 1.18, 1.49) (Fig.. 1). The features "change" and "more than one color" were the only ones in which the odds were significantly greater than 1.00 (so that more than 50% of respondents gave extreme importance ~o these features). The odds that respondents perceived the features "uneven edges" (OR, 0.64; 95% C1=0.57, 0.72), "elevation" (OR, 0.59; 95% CI -- 0.53, 0.67), and "size" (OR, 0.57; 95% CI = 50, 0.64) as extremely important were not significantly different, but all three were significantly lower than the odds f o r " change" and "more than one color." Of the six skin features, "hair" was least likely (OR,
0.33; 95% CI=0.29. 0.38) to be perceived as extremely important. Women were more likely to perceive each feature as being extremely important (significant sex main effect: X2= 17.71; d f = 2 ; p = 0.001) (Table I). The size of this sex difference did not appear to depend on the feature itself. There was a significant effect according to age (X2 = 28.46; d f = 4; p < 0.0001) on the importance scores. Moreover, the direction of this age effect depended on the feature itself (significant age by feature interaction: Xa = 64.75; df= 20; p < 0.001) (Table I). The greatest age variation was observed in relation to change. Younger respondents were most likely to perceive change as being extremely important, whereas older respondents were least likely. However, the reverse occurred for each of the remaining features; older respondents were most likely to place extreme importance on static skin featm-es, whereas younger respondents were least likely. The importance scores assigned by respondents to the six features were significantly influenced by education level (significant education main effect: X2= 36.97; d f = 6 ; p <0.0001), although the nature of the effect varied with the features (significant education by feature interaction: X2 = 73.39; df= 30;
36
Journal of the American Academy of Dermatology January 1997
Baade et al.
Table I. Odds that respondents placed extreme importance on each skin feature, by demographic characteristics Feature Population characteristic
Sex*
Age (yr)*'?
Education*,?
Sub-
group
Uneven
No.
Change
Color
edges
Elevation
Size
Hair
Male
529
Female
618
18-29
130
30-59
686
->60
316
Primary
321
Junior
427
Senior
187
Tertiary
202
3.34 (2.73, 4.08) 6.10 (4.87, 7.66) 5.19 (3.25, 8.28) 4.91 (4.02, 6.00) 3.39 (2.61, 4.41) 3.52 (2.71, 4.58) 5.78 (4.42, 7.55) 4.34 (3.01, 6.27) 4.32 (3.03, 6.14)
1.12 (0.94, 1.32) 1.55 (1.32, 1.83) 1.36 (0.96, 1.93) 1.29 (1.11, 1.50) 1.38 (1.10, 1.72) 1.68 (1.34,2.10) 1.39 (1.14, 1.68) 1.20 (0.90, 1.60) 0.92 (0.70, 1.22)
0.53 (0.44,0.63) 0.75 (0.64,0.88) 0.40 (0.27,0.58) 0.62 (0.53,0.72) 0.79 (0.63,0.98) 0.81 (0.65, 1.01) 0.62 (0.51,0.75) 0.55 (0.40,0.74) 0.53 (0.40,0.71)
0.53 (0.44,0.63) 0.66 (0.56,0.77) 0.41 (0.28,0.60) 0.58 (0.50,0.68) 0.69 (0.57,0.87) 0.75 (0.60,0.94) 0.61 (0.50,0.74) 0.59 (0.43,0.79) 0.38 (0128,0.52)
0.50 (0.42,0.60) 0.63 (0.53,0.74) 041 (0.28,0.60) 0.56 (0.48,0.65) 0.65 (0.52,0.82) 0.72 (0.57,0.89) 0.55 (0.45,0.67) 0.60 (0.44,0.80) 0.39 (0.29,0.53)
0.30 (0.24,0.37) 0.37 (0.31,0.44) 0.18 (0.11,0.29) 0.29 (0.25,0.35) 0.53 (0.42,0.66) 0.54 (0.43,0.68) 0.35 (0.28,0.44) 0.22 (0.15,0.32) 0.17 (0.11,0.25)
Data expressed as odds ratio with 95% confidence intervals given in parentheses. *Statistically significant difference in lrichotomized importance scores across demographic characteristics (p < 0.05). tStatistically significant interaction between the feature and the demographic characteristics (p < 0.05).
p < 0.001) (Table I). As was observed with age, the effect of education on the importance of change was different from the effect of education on the other skin features. Primary school-educated respondents were most likely to place extreme importance on each static feature, followed by those with junior, senior, and tertiary levels of education. However, primary school-edueated respondents were least likely to place extreme importance on change, with junior-educated respondents most likely, followed by senior and tertiary school-educated respondents. Whether or not respondents checked their skin in the past 3 months had a significant effect on the importance they placed on each feature (significant main effect: X2 = 14.16; df= 2; p--0.0008) (Table ID. Moreover, the magnitude of this effect varied with the features (significant interaction effect: X2 = 42.24; df= 0; p < 0.0001). For the majority of features, respondents who reported to have recently checked their skin were more likely to place extreme importance on the feature than those who have not checked their skin recently. However for size, the converse effect was true.
There was no significant evidence that having had a recent skin check by a physician in the past 3 months influenced the importance scores for any feature (nonsignificant main effect: ×2 = 2.34; df= 2; p = 0.3105) (Table II). Respondents with high perceived knowledge of the steps to follow when checking their skin were more likely to place extreme importance on each feature than those with low perceived knowledge levels (significant knowledge effect: X2= 17.05; df= 2; p = 0.0002). Although the direction of this knowledge effect was consistent across all six features, there was significant variation (X2 = 24.35; df= 10; p = 0.0067) in the magnitude of this knowledge effect with the skin features (Table l/I). There was a significant association between a respondent' s perceived knowledge of the skin features to look for when checking their skin and the importance they placed on each feature (significant knowledge effect: X2 = 12.80; df= 2;p = 0.0017). Respondents who thought they knew the features to look for were more likely to place extreme importance on all the features (Table liD. There was only weak evidence that the effect varied across the features
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Baade et aL 37
Table II° Odds that respondents placed extreme importance on each skin feature, by recent skin examinations Feature Population
characteristic
Skin Selfexamination*,? Self exarr/anation by physician
Recent 727
5.43 (4.45, 6.64) None 421 3.34 (2.66, 4.19) Recent 169 5.04 (3.35, 7.55) None 979 4.38 (3.73, 5.14)
Color
I Uneven edges i
Elevation
1.42 (1.22, 1.64) 1.19 (0.98, 1.45) 1.68 (1.23, 2.30) 1.28 (1.13, 1.45)
0.74 (0.64, 0.86) 0.49 (0.40, 0.60) 0.80 (0.59, 1,08) 0i61 (0.54, 0.70)
0.62 (0.53, 0.72) 0,55 (0.45, 0.68) 0.67 (0.50,0.92) 0.58 (0,51, 0.66)
I
Size
f
0:55 (0.47, 0,64) 0,59 (0.48, 0:72) 0,51 (0.37, 0:70) 0,58 (0.51, 0.67)
Hair
0,35 (0,30; 0.4I) 0,31 (0,25, 0.39) 0.36 (0.26, 0.51) 0.33 (0,29,0:38)
Data expressed as odds ratios with 95% confidence intervals given in parentheses. *Statistically significant difference in trichotomized importance scores across demographic characteristics (p < 0.05). ?Statistically significant interaction between the feature and the demographic characteristics (p < 0.05).
Table III. Odds that respondents placed extreme importance on each skin feature, by attitudinal responses
characteristic
Perceived knowledge of steps*,?
Change
High
879
5.23 (4.37,6.27) Low 264 3.00 (227, 3.96) Perceived :knowledge High 955 5.0l of featm'es*,? (4.22, 5.94) Low 188 2.92 (2.10,4.05) Perceived self-efficacy* High 1016 5.01 (4.25, 5.91) Low 129 2.23 (1.53, 3.23)
Color
Uneven edges
Elevation
1.42 (1.24, 1.63) 1.08 (0.85, 1.37) 1.37 (1.20, 1.56) 1.16 (0.87, 1.55) 1.39 (1.23, 1.58) 0.93 (0.66, 1.31)
0.69 (0.60,0.79) 0A7 (0.37, 0.61) 0.66 (0.58, 0.75) 0.54 (0.40,0.73) 0.66 (0.58, 0.75) 0.48 (0.33, 0.70)
0.64 (0.56,0.73) 0.47 (0,36,0.60) 0.60 (0.53, 0.68) 0:57 (0.42,0.76) 0.61 (0,54, 0,70) 0.45 (0.31, 0.65)
Size
0.59 0.36 (0:51,0,67)(0.31,0.42) 0.51 0:26 (0.39, 0.66) (0:19, 0.35) 0.57 0.34 (0.50, 0.65) (0,29, 0.39) 0.55 0.33 (0.41,0.75) (0.24,0:46) 0.59 0.34 (0.52, 0.67) (0.30, 0.39) 0.40 0.29 (0.27, 059) (0.!9, 0,44)
Data expressed as odds ratios with 95% confidence intervals given in parentheses. *Statistically significant difference in trichotomized importance scores across demographic characteristics (p < 0.05). ?Statistically significant interaction between the feature and the demographic characteristics (p < 0.05),
(significant interaction: ×2= 18.36; df=10; p =
0.O492), Perceived self-efficacy had a significant effect on the importance score placed on each skin feature (X2 = 8.53; df= 2; p = 0.0140). Respondents who thought they could identify a suspect lesion on their skin were more likely to place extreme importance on all the t~amres. There was no evidence that the size of this effect varied significantly with the features (Table III). DISCUSSION
Recent public education programs in Australia such as the "Spot the Difference Campaign," con-
ducted by the Australian Cancer Society, have not placed particular emphasis on change of the lesion. However, the community clearly perceives that "change" is the most i m p o ~ n t feature when checking for early signs of skin cancer. Effective detection of change requires regular monitoring of skin lesions over time, by either the person or a physician. Campaigns encouraging the public to look for change in a skin lesion assume that persons check their skin regularly, that they can remember what the lesion used to look like,: and that they can identify differences that are now present. However, previous research has suggested that skin serf-examination is not adequate 11; in this study only
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Baade et aL
15% of this sample had their skin recently checked by their family physician. Therefore, to detect change in a skin lesion, a substantial improvement in the quality of skin examination may be needed. An additional approach, which can be pursued simultaneously, is to expand the focus of education campaigns to encourage the public to concentrate on looking for static skin features, which may be easier to identify. This approach could use an easy-toremember method, such as the "ABCD" role recommended by the American Cancer Society.6'25 This focus could increase the community's perceived importance of those features that this study found to be low; less than 50% of respondents placed extreme importance on "size" or "uneven edges," both of which form part of the "ABCD" rule, and "elevation," which is sometimes included.7 However, care may need to be taken when these checldists are applied to community education. These checklists were developed with the characteristics of lesions presented by patients to dermatologists; hence they do not consider those persons who, particularly in Australia, have been previously screened by a family physician. It would be useful to study which skin features are most prevalent in the general population and to determine whether separate checklists should be developed for the community as distinct from those used by specialists. Newman et al.17 found low community concern for two aspects of change: growth and color. These findings were not replicated in this study. Differences may be due to the different populations and environments in the two studies (Queensland compared with the United Kingdom). Newman et al. also found that the proportion of respondents concerned about change varied depending on the change specified; it may be that persons recognize change as being important, but they are not as confident when asked about specific types of change. Respondents clearly gave the presence of hair in a skin lesion the lowest importance, but 25% of respondents thought that hair was extremely important as an early sign of melanoma. Although education about this fallacy may reduce the number of benign lesions presented to a family physician, it may also increase the number of malignant lesions not presented, by incorrectly reassuring a person whenever hair was near a suspect skin lesion. The higher importance scores assigned by women may suggest similar discerning power between the
Journal of the American Academy of Dermatology January 1997
sexes or may be attributed to the fact that women are more concerned with their skin and their general health26 and more likely to engage in preventive behaviors than m e n Y Younger respondents were more likely to rate change as extremely important than older respondents. This effect was reversed for the other static skin features. Similarly, groups with less education tended to rate all features more highly than groups receiving higher education, except for the feature "change." These differences may suggest that the population subgroups respond differently to the general education campaigns currently used. Perhaps the targeting of furore campaigns should be more specific to reach each of these subgroups adequately. Knowledge and self-efficacy appear to be related more to the magnitude of the importance score, rather than a different discrimination between features. This may not be surprising, given that education campaigns have linked all the features (except "hair") with higher risk of melanoma. Hence an increased awareness of the risk of melanoma may increase the perceived importance of the skin features generally, without persons necessarily considering whether each feature is more or less likely to be associated with melanoma. Respondents who had checked their skin recently were more likely to give greater importance to all six skin features than those who had not checked their skin. Skin self-examination implies some measure of personal awareness of the importance of detecting skin cancer early, and this awareness may have contributed to the increase in importance scores. However, the importance scores of respondents who had seen a physician recently for a skin check were no different from the scores of those who had not; this may suggest that physicians are not taking advantage of the opportunity when they examine a patient's skin to discuss the important features and the procedures to follow when looking for signs of early melanoma. W e acknowledge the assistance o f the Epidemiology and Health Information Branch, Queensland Health. REFERENCES
1. Maclennan R, Green AC, McLeod GRC, et al. Increasing incidence of cutaneous melanoma in Queensland, Auslrafla. JNCI 1992;84:1427-31. 2. Stenbeck KD, Balanda KP, Williams MJ, et al. Patterns of treated non-melanoma skin cancer in Queensland--the re-
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gion with the highest incidence rates in the world. Med J Aust 1990;153:511-5. Elwood JM, Crooke KR, Coombs BD, etal. A strategy for the control of malignant melanoma in New Zealand. N Z Med J 1988;10i:602-4. Friedman RJ, Rigel DS, Silverman MK, et al. Malignant melanoma in the 1990s: the continued importance of early detection and the role of physician examination and selfexaminationof the skin. CA Cancer J Clin 1991;41:201-26. Elwood JM. Screening for melanoma and options for its evaluation. J Med Screen 1994;1:22-38. Rigel DS, Friedman RJ. The rationale of the ABCDs of early melanomas [letter]. J Am Acad Dermatol 1993;29: 1060-1. FitzpalzdckTB, Rhodes AR, Sober AJ, etal. Primary malignant melanoma of the skin: the call for action to identify persons at risk; to discover precursor lesions; to detect early melanomas. Pigment Cell Res 1988;9:110-7. MacKie RM. Clinical recognition of early invasive malignant melanoma: looldng for changes in size, shape and color is successful. Br Med J 1990;301:1005-6. Shaw HM, McCmnhy WH. Small-diameter malignant melanoma: a common diagnosis in New South Wales, Australia. J Am Acad Dermatol !992;27:679-82. McGovem TW, Litaker MS. Clinical predictors of malignant pigmented lesions: a comparison of the Glasgow seven-point checklist and the American Cancer Society's ABCDs of pigmented lesions. J Dermatol Surg Oncol 1992; 18:22-6. BalancLaKP, Lowe JB, Stanton WR, et al. Enhancing the early detection of melanoma within current guidelines. Aust J Public Health 1994;18:420-3. Girgis A. Screening for melanoma. Med J Aust 1991; 154:707-8. Borland R, Meehan JW. Skin examinationfor signs of skin cancer. Aust J Public Health 1995;19;85-7. Friedman LC, Bruce S, Webb JA. Skin self-examination in a population at increased risk for skin cancer. Am J Prev Med i993;9:359-64. Gruber SB, Roush GC, Bamhill RL. Sensitivity and spec-
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Community perceptions about the important signs of early melanoma Peter D. Baade, MedSc, Kevin P. Balanda, Phi), Warren R. Stanton, PhD, Amaya M. Gillespie, PhD, and John B. Lowe, DrPH Herston, Queensland, Australia
Background: Detecting melanoma early often relies on patient concern about a particular pigmented lesion. However, it is not clear what specific features the public views as being important. Objective: Our purpose was to explore the importance persons place on wxious features of skin lesions when looking for early signs of melanoma. Methods: This study comprised 1148 respondents (participation rate, 78%) from 60 rural communities in Queensland, Australia, who participated in a telephone interview. Results: The following features were considered important and are listed in order of importance: change in the lesion (clearly identified as the most important), more than one color, uneven edges, elevation, large size (the last three of equal importance), and hairiness of the lesion. Age, sex, education, self-efficacy, perceived knowledge, and recent self-examination influenced importance levels, but having a recent skin examination by a family physician did not.
Conclusion: To increase the skin serf-examination s~lls of the community, guidelines may have to become more specific and all opportunities fully utilized to educate the public. 0 Am Acad Dermatol 1997;36:33-9.)
Australia, in particular Queensland, has the highest reported incidence of melanoma and nonmelanoma skin cancer in the world. 1,2 Early detection offers the best oppommity to reduce mortality. 3, 4 However, international recommendations for skin seN-examination and screening for skin cancer vary considerably. 5 Several clinical criteria such as the " A B C D " rule, 6 the " A B C D E " nile, 7 and the Glasgow revised 7-point checklist 8 have been promoted to assist in the diagnosis of pigmented lesions. However, the composition of these criteria is not without controversy,6, 9 and "theyhave not been able to meet the desired level of sensitivity and specificity. 1° At least 50% of adults in Australia and overseas
From the Centre for Health Promotion and Cancer Prevention Researcl~ Medical School, University of Queensland. Support for the telephone survey was given by the Queensland Cancer Fund. Accepted for pubfication July 20, 1996. Reprint requests: Peter Baade, Centre for Health Promotion and Cancer Prevention Research, Medical School, University of Queensland, Herston Road. Herston, Queensland 4006, Australia. Copyright © 1997 by the American Academy of Dermatology, Inc. 0190-9622/97L'~5.00 + 0 16/1/76711
report that their skin is checked for early signs of skin cancer, either by themselves or with the assistance of another person or a health professional. 11-14 However, concern has been expressed about the adequacy of these reported skin checks. 11 The efficacy of skin self-examination is unknown. It has been shown that patients without melanoma can accurately report nevus counts, 15 but another study found that the public tend not to be able to identify photographs of early melanomas) 6 Thus there is some evidence that community members do not use appropriate guidelines to detect a suspect lesion and to decide whether a particular lesion warrants further attention. In addition, the public often delays in showing lesions to a physician, 17which further reduces the likelihood of a satisfactory prognosis. Possible reasons for delays in presentation may be lack of knowledge on the part of the patient, as distinct from fear or denial, 18 a perception that the lesion is not serious, 19 and the inability to see an evolving rumor. 2° This behavior has led several researchers to call for educational campaigns to increase awareness about malignant melanoma 17,2° and to inform the public about the existence of guidelines and methods in applying the criteria. 16 To design such campaigns it is first necessary to understand community per33
34
Baade et al.
ceptions. However, only a few investigators have systematically studied the perceived importance placed on particular features o f skin lesions. One study found that twice as m a n y persons thought an early melanoma was raised or could be raised than those who thought it was flat. 16 The same study found that most respondents thought "darkness," " b e i n g different," or " u g l y " were c o m m o n characteristics o f melanomas. Another study found that 40% o f respondents thought an irregular outline and a mixture o f colors were characteristics of normal moles, and a third thought it was normal for moles to grow. 17 There is an urgent need for research into the process of skin serf-examination and its role in the early detection o f mafignant melanoma. 21 Cassileth et al.22 outlined four steps that lead to diagnosis of melanoma: initial awareness by the patient, suspicion or concern about that lesion, seeking medical advice, and diagnosis b y the physician. The focus of this study is the second step, specifically, to determine those features considered important signs of early melanoma b y community members.
METHODS A telephone survey of Queensland adults was conducted. The sample was drawn from 60 rural communities throughout Queensland with populations between 1000 and 4000, and it was stratified by sex. The telephone interviews were conducted with a computer-aided telephone interviewing (CATI) system in October and November 1994. Telephone numbers were randomly drawn from a list of private telephone numbers. Six attempts were made to contact potential respondents before a household was considered "noncontactable." Respondents were asked about six skin features: size (larger'than the blunt end of a pencil), change (having changed during the past 6 months), elevation (being elevated or raised), uneven edges, lesion of more than one color, and hair. The first five features were abstracted from several published skin examination guidelines, s,23 although the selection was not exhaustive. The presence of hair in a skin lesion was then included as a comparison feature. For each of these features, respondents were asked, " f f y o u were checldng your skin for early signs of skin cancer and you found a mole or spot that had (the feature), how important would you rate this on a scale of 0 to 10, where 0 is not important, and 10 is extremely important?" These six importance scores were then collapsed into three importance categories (extreme, medium, and low). The distributions of the six importance scores were similar. The shape of the distributions suggested that a score
Journal of the American Academy of Dermatology January 1997
of 5 (the midpoint of the 11-point scale) was used by respondents as an "unsure" option. A score up to 5 was thus taken to show that the respondent considered the feature either not important or of uncertain importance. There was also a concentration of scores in the higher importance levels, and the interviewer, in saying that "10 is extremely important," forced a differentiation between scores of 9 and below and 10. Therefore the three importance categories used in this analysis were as follows: extreme perceived importance (score = 10), moderate perceived importance (6---score ~< 9), and low perceived importance (0 -< score --< 5). Three attitudinal questions were included in the questionnaire: perceived knowledge of the steps involved in checking their skin ("I think I know the steps to follow to check my body for early signs of skin cancer"), perceived knowledge of features ("I think I know what features I should be looking for to check for skin cancer"), and self-efficacy ("I think I could identify something suspect on my skin"). Responses were recorded on a 5-point Likert scale ranging from "strongly agree" to "strongly disagree." For analysis, these scales were collapsed to "agree"/"not agree," with the "not sure" option included in "not agree." Details about the respondents' age (18 to 29 years, 30 to 59 years, 60 years and older), sex, and highest level of completed education were collected. Respondents were also asked whether they had checked their skin for early signs of skin cancer in the past 3 months and whether a physician had checked their skin in the past 3 months. The analysis focuses on the odds that a person will perceive a feature to be extremely important. A repeatedmeasures logistic ordinal regression model including a factor called "feature," with six levels representing each of the sldn features, was first used to estimate the odds that respondents perceived each specific skin feature to be extremely important, moderately important, or of low importance. Separate logistic ordinal regression models were then used to explore the effect of sex, age, education level, recent skin self-examination, recent skin check by a physician, knowledge of steps, knowledge of features, and self-efficacy. For each such variable, the initial base model (including "feature" only) was extended to include the variable and an interaction term (variable by feature) to assess whether its effect varied with the feature. Significance of main effects and interactions Was assessed with the chi-square statistic (X2) from these extended repeated-measures ordinal regression models.24
RESULTS W e attempted to call a total o f 2566 t e l e p h o n e numbers from the target population. O f these, 582 were ineligible and 512 households could not be contacted. The ineligible telephone numbers arose
Journal of the American Academy of Dermatology Volume 36, Number 1
Baade et aL 35
Odds 6
I Change
1 Color
Edges
l Elevated
1 Size
Hair
Feature Fig. 1. Odds of placing extreme importance (score, 10) on each of six specific features of
skin lesions when checking for early signs of skin cancer (with 95% corffidence intervals). (Results of repeated measures ordinal logistic regression.)
from business or commercial numbers or were those outside t~_e town's defined boundaries; numbers were also considered ineligible when the sex quota cells were filled. Of the eligible people contacted (n = 1472), 78% completed the telephone interview, resulting in 1148 completed interviews. Compared with the Queensland adult population, women (53.9% in sample, 50.4% in population) and those older than 40 years of age (63.7% in sample. 52.6% in population) were overrepresented in the sample. The odds ratio (OR) that change was perceived as extremely important was 4.47 (95% confidence interval [C1] = 3.85, 5.19), significantly higher than the odds that the feature more than one color was perceived as e,xtremely important (1.33; 95% CI = 1.18, 1.49) (Fig.. 1). The features "change" and "more than one color" were the only ones in which the odds were significantly greater than 1.00 (so that more than 50% of respondents gave extreme importance ~o these features). The odds that respondents perceived the features "uneven edges" (OR, 0.64; 95% C1=0.57, 0.72), "elevation" (OR, 0.59; 95% CI -- 0.53, 0.67), and "size" (OR, 0.57; 95% CI = 50, 0.64) as extremely important were not significantly different, but all three were significantly lower than the odds f o r " change" and "more than one color." Of the six skin features, "hair" was least likely (OR,
0.33; 95% CI=0.29. 0.38) to be perceived as extremely important. Women were more likely to perceive each feature as being extremely important (significant sex main effect: X2= 17.71; d f = 2 ; p = 0.001) (Table I). The size of this sex difference did not appear to depend on the feature itself. There was a significant effect according to age (X2 = 28.46; d f = 4; p < 0.0001) on the importance scores. Moreover, the direction of this age effect depended on the feature itself (significant age by feature interaction: Xa = 64.75; df= 20; p < 0.001) (Table I). The greatest age variation was observed in relation to change. Younger respondents were most likely to perceive change as being extremely important, whereas older respondents were least likely. However, the reverse occurred for each of the remaining features; older respondents were most likely to place extreme importance on static skin featm-es, whereas younger respondents were least likely. The importance scores assigned by respondents to the six features were significantly influenced by education level (significant education main effect: X2= 36.97; d f = 6 ; p <0.0001), although the nature of the effect varied with the features (significant education by feature interaction: X2 = 73.39; df= 30;
36
Journal of the American Academy of Dermatology January 1997
Baade et al.
Table I. Odds that respondents placed extreme importance on each skin feature, by demographic characteristics Feature Population characteristic
Sex*
Age (yr)*'?
Education*,?
Sub-
group
Uneven
No.
Change
Color
edges
Elevation
Size
Hair
Male
529
Female
618
18-29
130
30-59
686
->60
316
Primary
321
Junior
427
Senior
187
Tertiary
202
3.34 (2.73, 4.08) 6.10 (4.87, 7.66) 5.19 (3.25, 8.28) 4.91 (4.02, 6.00) 3.39 (2.61, 4.41) 3.52 (2.71, 4.58) 5.78 (4.42, 7.55) 4.34 (3.01, 6.27) 4.32 (3.03, 6.14)
1.12 (0.94, 1.32) 1.55 (1.32, 1.83) 1.36 (0.96, 1.93) 1.29 (1.11, 1.50) 1.38 (1.10, 1.72) 1.68 (1.34,2.10) 1.39 (1.14, 1.68) 1.20 (0.90, 1.60) 0.92 (0.70, 1.22)
0.53 (0.44,0.63) 0.75 (0.64,0.88) 0.40 (0.27,0.58) 0.62 (0.53,0.72) 0.79 (0.63,0.98) 0.81 (0.65, 1.01) 0.62 (0.51,0.75) 0.55 (0.40,0.74) 0.53 (0.40,0.71)
0.53 (0.44,0.63) 0.66 (0.56,0.77) 0.41 (0.28,0.60) 0.58 (0.50,0.68) 0.69 (0.57,0.87) 0.75 (0.60,0.94) 0.61 (0.50,0.74) 0.59 (0.43,0.79) 0.38 (0128,0.52)
0.50 (0.42,0.60) 0.63 (0.53,0.74) 041 (0.28,0.60) 0.56 (0.48,0.65) 0.65 (0.52,0.82) 0.72 (0.57,0.89) 0.55 (0.45,0.67) 0.60 (0.44,0.80) 0.39 (0.29,0.53)
0.30 (0.24,0.37) 0.37 (0.31,0.44) 0.18 (0.11,0.29) 0.29 (0.25,0.35) 0.53 (0.42,0.66) 0.54 (0.43,0.68) 0.35 (0.28,0.44) 0.22 (0.15,0.32) 0.17 (0.11,0.25)
Data expressed as odds ratio with 95% confidence intervals given in parentheses. *Statistically significant difference in lrichotomized importance scores across demographic characteristics (p < 0.05). tStatistically significant interaction between the feature and the demographic characteristics (p < 0.05).
p < 0.001) (Table I). As was observed with age, the effect of education on the importance of change was different from the effect of education on the other skin features. Primary school-educated respondents were most likely to place extreme importance on each static feature, followed by those with junior, senior, and tertiary levels of education. However, primary school-edueated respondents were least likely to place extreme importance on change, with junior-educated respondents most likely, followed by senior and tertiary school-educated respondents. Whether or not respondents checked their skin in the past 3 months had a significant effect on the importance they placed on each feature (significant main effect: X2 = 14.16; df= 2; p--0.0008) (Table ID. Moreover, the magnitude of this effect varied with the features (significant interaction effect: X2 = 42.24; df= 0; p < 0.0001). For the majority of features, respondents who reported to have recently checked their skin were more likely to place extreme importance on the feature than those who have not checked their skin recently. However for size, the converse effect was true.
There was no significant evidence that having had a recent skin check by a physician in the past 3 months influenced the importance scores for any feature (nonsignificant main effect: ×2 = 2.34; df= 2; p = 0.3105) (Table II). Respondents with high perceived knowledge of the steps to follow when checking their skin were more likely to place extreme importance on each feature than those with low perceived knowledge levels (significant knowledge effect: X2= 17.05; df= 2; p = 0.0002). Although the direction of this knowledge effect was consistent across all six features, there was significant variation (X2 = 24.35; df= 10; p = 0.0067) in the magnitude of this knowledge effect with the skin features (Table l/I). There was a significant association between a respondent' s perceived knowledge of the skin features to look for when checking their skin and the importance they placed on each feature (significant knowledge effect: X2 = 12.80; df= 2;p = 0.0017). Respondents who thought they knew the features to look for were more likely to place extreme importance on all the features (Table liD. There was only weak evidence that the effect varied across the features
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Baade et aL 37
Table II° Odds that respondents placed extreme importance on each skin feature, by recent skin examinations Feature Population
characteristic
Skin Selfexamination*,? Self exarr/anation by physician
Recent 727
5.43 (4.45, 6.64) None 421 3.34 (2.66, 4.19) Recent 169 5.04 (3.35, 7.55) None 979 4.38 (3.73, 5.14)
Color
I Uneven edges i
Elevation
1.42 (1.22, 1.64) 1.19 (0.98, 1.45) 1.68 (1.23, 2.30) 1.28 (1.13, 1.45)
0.74 (0.64, 0.86) 0.49 (0.40, 0.60) 0.80 (0.59, 1,08) 0i61 (0.54, 0.70)
0.62 (0.53, 0.72) 0,55 (0.45, 0.68) 0.67 (0.50,0.92) 0.58 (0,51, 0.66)
I
Size
f
0:55 (0.47, 0,64) 0,59 (0.48, 0:72) 0,51 (0.37, 0:70) 0,58 (0.51, 0.67)
Hair
0,35 (0,30; 0.4I) 0,31 (0,25, 0.39) 0.36 (0.26, 0.51) 0.33 (0,29,0:38)
Data expressed as odds ratios with 95% confidence intervals given in parentheses. *Statistically significant difference in trichotomized importance scores across demographic characteristics (p < 0.05). ?Statistically significant interaction between the feature and the demographic characteristics (p < 0.05).
Table III. Odds that respondents placed extreme importance on each skin feature, by attitudinal responses
characteristic
Perceived knowledge of steps*,?
Change
High
879
5.23 (4.37,6.27) Low 264 3.00 (227, 3.96) Perceived :knowledge High 955 5.0l of featm'es*,? (4.22, 5.94) Low 188 2.92 (2.10,4.05) Perceived self-efficacy* High 1016 5.01 (4.25, 5.91) Low 129 2.23 (1.53, 3.23)
Color
Uneven edges
Elevation
1.42 (1.24, 1.63) 1.08 (0.85, 1.37) 1.37 (1.20, 1.56) 1.16 (0.87, 1.55) 1.39 (1.23, 1.58) 0.93 (0.66, 1.31)
0.69 (0.60,0.79) 0A7 (0.37, 0.61) 0.66 (0.58, 0.75) 0.54 (0.40,0.73) 0.66 (0.58, 0.75) 0.48 (0.33, 0.70)
0.64 (0.56,0.73) 0.47 (0,36,0.60) 0.60 (0.53, 0.68) 0:57 (0.42,0.76) 0.61 (0,54, 0,70) 0.45 (0.31, 0.65)
Size
0.59 0.36 (0:51,0,67)(0.31,0.42) 0.51 0:26 (0.39, 0.66) (0:19, 0.35) 0.57 0.34 (0.50, 0.65) (0,29, 0.39) 0.55 0.33 (0.41,0.75) (0.24,0:46) 0.59 0.34 (0.52, 0.67) (0.30, 0.39) 0.40 0.29 (0.27, 059) (0.!9, 0,44)
Data expressed as odds ratios with 95% confidence intervals given in parentheses. *Statistically significant difference in trichotomized importance scores across demographic characteristics (p < 0.05). ?Statistically significant interaction between the feature and the demographic characteristics (p < 0.05),
(significant interaction: ×2= 18.36; df=10; p =
0.O492), Perceived self-efficacy had a significant effect on the importance score placed on each skin feature (X2 = 8.53; df= 2; p = 0.0140). Respondents who thought they could identify a suspect lesion on their skin were more likely to place extreme importance on all the t~amres. There was no evidence that the size of this effect varied significantly with the features (Table III). DISCUSSION
Recent public education programs in Australia such as the "Spot the Difference Campaign," con-
ducted by the Australian Cancer Society, have not placed particular emphasis on change of the lesion. However, the community clearly perceives that "change" is the most i m p o ~ n t feature when checking for early signs of skin cancer. Effective detection of change requires regular monitoring of skin lesions over time, by either the person or a physician. Campaigns encouraging the public to look for change in a skin lesion assume that persons check their skin regularly, that they can remember what the lesion used to look like,: and that they can identify differences that are now present. However, previous research has suggested that skin serf-examination is not adequate 11; in this study only
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Baade et aL
15% of this sample had their skin recently checked by their family physician. Therefore, to detect change in a skin lesion, a substantial improvement in the quality of skin examination may be needed. An additional approach, which can be pursued simultaneously, is to expand the focus of education campaigns to encourage the public to concentrate on looking for static skin features, which may be easier to identify. This approach could use an easy-toremember method, such as the "ABCD" role recommended by the American Cancer Society.6'25 This focus could increase the community's perceived importance of those features that this study found to be low; less than 50% of respondents placed extreme importance on "size" or "uneven edges," both of which form part of the "ABCD" rule, and "elevation," which is sometimes included.7 However, care may need to be taken when these checldists are applied to community education. These checklists were developed with the characteristics of lesions presented by patients to dermatologists; hence they do not consider those persons who, particularly in Australia, have been previously screened by a family physician. It would be useful to study which skin features are most prevalent in the general population and to determine whether separate checklists should be developed for the community as distinct from those used by specialists. Newman et al.17 found low community concern for two aspects of change: growth and color. These findings were not replicated in this study. Differences may be due to the different populations and environments in the two studies (Queensland compared with the United Kingdom). Newman et al. also found that the proportion of respondents concerned about change varied depending on the change specified; it may be that persons recognize change as being important, but they are not as confident when asked about specific types of change. Respondents clearly gave the presence of hair in a skin lesion the lowest importance, but 25% of respondents thought that hair was extremely important as an early sign of melanoma. Although education about this fallacy may reduce the number of benign lesions presented to a family physician, it may also increase the number of malignant lesions not presented, by incorrectly reassuring a person whenever hair was near a suspect skin lesion. The higher importance scores assigned by women may suggest similar discerning power between the
Journal of the American Academy of Dermatology January 1997
sexes or may be attributed to the fact that women are more concerned with their skin and their general health26 and more likely to engage in preventive behaviors than m e n Y Younger respondents were more likely to rate change as extremely important than older respondents. This effect was reversed for the other static skin features. Similarly, groups with less education tended to rate all features more highly than groups receiving higher education, except for the feature "change." These differences may suggest that the population subgroups respond differently to the general education campaigns currently used. Perhaps the targeting of furore campaigns should be more specific to reach each of these subgroups adequately. Knowledge and self-efficacy appear to be related more to the magnitude of the importance score, rather than a different discrimination between features. This may not be surprising, given that education campaigns have linked all the features (except "hair") with higher risk of melanoma. Hence an increased awareness of the risk of melanoma may increase the perceived importance of the skin features generally, without persons necessarily considering whether each feature is more or less likely to be associated with melanoma. Respondents who had checked their skin recently were more likely to give greater importance to all six skin features than those who had not checked their skin. Skin self-examination implies some measure of personal awareness of the importance of detecting skin cancer early, and this awareness may have contributed to the increase in importance scores. However, the importance scores of respondents who had seen a physician recently for a skin check were no different from the scores of those who had not; this may suggest that physicians are not taking advantage of the opportunity when they examine a patient's skin to discuss the important features and the procedures to follow when looking for signs of early melanoma. W e acknowledge the assistance o f the Epidemiology and Health Information Branch, Queensland Health. REFERENCES
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