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Abstract
Objective Skin cancer is Australia’s most common and costly cancer. We examined the frequency of Australian general practice consultations for skin cancer-related conditions, by patient and general practitioner (GP) characteristics and by time period.
Design Nationally representative, cross-sectional survey of general practice clinical activity.
Setting, participants Patients aged 15 years or older having a skin cancer-related condition managed by GPs in the Bettering the Evaluation And Care of Health study between April 2000 and March 2016.
Primary outcome measures Proportions and rates per 1000 encounters.
Results In this period, 15 678 GPs recorded 1 370 826 patient encounters, of which skin cancer-related conditions were managed 65 411 times (rate of 47.72 per 1000 encounters, 95% CI 46.41 to 49.02). Across the whole period, ‘skin conditions’ managed were solar keratosis (29.87%), keratinocyte cancer (24.85%), other skin lesion (12.93%), nevi (10.98%), skin check (10.37%), benign skin neoplasm (8.76%) and melanoma (2.42%). Over time, management rates increased for keratinocyte cancers, skin checks, skin lesions, benign skin neoplasms and melanoma; but remained stable for solar keratoses and nevi. Skin cancer-related encounter rates were higher for patients aged 65–89 years, male, living in Queensland or in regional or remote areas, with lower area-based socioeconomic status, of English-speaking background, Veteran card holders and non-healthcare card holders; and for GPs who were aged 35–44 years or male.
Conclusion These findings show the spectrum and burden of skin cancer-related conditions managed in general practice in Australia, which can guide GP education, policy and interventions to optimise skin cancer prevention and management.
- EPIDEMIOLOGY
- PRIMARY CARE
- Dermatological tumours
Data availability statement
All data relevant to the study are included in the article or uploaded as online supplemental information. Data were obtained from the Bettering the Evaluation and Care of Health (BEACH) study team, who can be contacted for data sharing requests: christopher.harrison@sydney.edu.au.
This is an open access article distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited, appropriate credit is given, any changes made indicated, and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/.
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STRENGTHS AND LIMITATIONS OF THIS STUDY
This study describes the different skin cancer-related conditions managed in a large Australian representative sample of general practice encounters. Representativeness of the general practitioner sample was validated at each recruitment period.
The data collection form allowed for up to four conditions managed in a general practice encounter to be recorded; these data are not available in administrative data collections.
A limitation was the cross-sectional nature of the study, as we could not follow patients over time to examine the number of repeated consultations, nor skin cancer outcomes.
Data were not diagnostically verified.
Introduction
Australia’s most common and costly cancers for the health system is skin cancer, which comprises melanoma and keratinocyte cancers (basal cell carcinoma, and squamous cell carcinoma (SCC)).1 Internationally, skin cancer incidence rates are highest in Australia and New Zealand.2 In the Australian Healthcare system costs, keratinocyte cancers contributed $A1.326 million in 2018–2019.3 Skin biopsy rates have increased by an estimated 66% over the past decade,4 and melanoma treatment costs increased from an estimated $A30 million in 2001 to $A272 million in 20175 and continue to rapidly grow due to the availability of immunotherapies. Skin checks are associated with early detection of melanoma and may reduce melanoma mortality,6 but without sufficient evidence to recommend national population screening, skin checks in most countries, including Australia, are conducted predominantly opportunistically.6
Most skin cancers and their precancerous lesions, including suspicious but benign lesions, are managed in primary care settings in Australia, yet we know little about the frequency of general practitioner (GP) visits for different types of skin cancer-related conditions. Previous Australian studies have focused on particular skin cancers or periods of time7–10 or other skin diseases11 and have not examined the rates of GP visits according to a range of patient characteristics. Understanding the scope and extent of managing skin cancer-related conditions in general practice is necessary to optimise skin cancer management and guide resource allocation for skin cancer management in primary care, particularly in regional areas. We aimed to examine the frequency of general practice consultations for different types of skin cancer-related conditions, and differences by patient and GP sociodemographic characteristics and by time period, from the Bettering the Evaluation and Care of Health (BEACH) study.12
Methods
Study design and participation
The BEACH study represents a continuous record of GP clinical activity between 1 April 1998 and March 2016 in Australia.12 The methods have been published previously.12 Each year, a new representative random sample of 1000 GPs (including GPs in skin cancer clinics) recorded details on 100 consecutive encounters with patients who gave consent, resulting in approximately 100 000 patient encounters per year. GPs that were randomly selected by the General Practice Branch of the Commonwealth Department of Health and Aged Care were approached by letter and a follow-up telephone call. GPs were eligible if they had claimed a minimum of 375 general practice Medicare items of service in the most recent 3-month Health Insurance Commission data period, which equates to 1500 claims/year. Of GPs that were contacted, 27.54% completed the BEACH study. Representativeness of the GP sample was validated at each recruitment period.12
Participating GPs recorded information about each encounter on a structured paper form in free text including encounter details, patient characteristics, up to three patient reasons for encounter in the patients’ own words and up to four problems/conditions managed. Trained clinical coders entered the data. Conditions managed were coded using the International Classification of Primary Care Version 2 PLUS (ICPC-2 PLUS)12 which is automatically classified to ICPC-2.12
Selection of skin cancer-related conditions
We selected seven skin cancer-related conditions for analysis (skin check, nevi, skin lesion, melanoma, other malignant skin neoplasm (excluding melanoma); benign/unspecified skin neoplasm; solar keratosis). Data prior to year 2000 were excluded for this analysis as there were differences in how some variables were collected. Definitions for each skin cancer-related condition are detailed in online supplemental table 1.
Supplemental material
Statistical analysis
Differences in skin conditions managed at encounters were compared over time and by different patient characteristics including age, sex, state or territory of residence, remoteness (based on the Australian Statistical Geographic Standard,13 area-based socioeconomic index (based on Socio-Economic Indexes for Areas Index of Relative Socio-Economic Advantage and Disadvantage index14 healthcare card status, Veterans Affair card and language spoken at home. Figures and analyses were produced using RStudio V.1.4.1717.15 Statistical comparisons over time and for different subgroups were conducted using χ2 tests and t-tests. Where appropriate, data are presented with 95% CIs. For descriptive comparisons, statistical significance was determined by non-overlapping CIs, a more conservative method than p<0.050.16
Patient and public involvement
No patient involved.
Results
Rates and proportions of different skin cancer conditions managed
Between April 2000 and March 2016, 15 678 GPs recorded 1 370 826 encounters with patients aged 15 years or older, of which skin cancer-related conditions were managed 65 411 times, a management rate of 47.72 (95% CI 46.41 to 49.02) per 1000 encounters. Skin cancer-related conditions accounted for 3.00% (95% CI 2.91% to 3.08%) of all problems managed.
For years 2000–2016 combined, the conditions managed in order of frequency were solar keratosis (29.87%, management rate 13.35 per 1000 encounters), keratinocyte cancer (24.85%, rate 11.29), other skin lesion (12.93%, rate 5.67), nevi (10.98%, rate 4.82), skin check (10.37%, rate 4.35), benign skin lesion (8.76%, rate 3.91) and melanoma (2.42%, rate 1.04). Management rates increased for skin conditions overall; particularly between 2000 and 2008, and separately for keratinocyte cancers, skin checks, skin lesions, benign skin neoplasms and melanoma, but remained stable for solar keratoses and nevi (figure 1A–C).
(A) Proportion of different skin cancer-related conditions managed in general practice, 2000–2016. (B) Management rate per 1000 encounters of all skin cancer-related conditions combined managed in general practice, 2000–2016. (C) Management rate per 1000 encounters of each skin cancer-related condition managed in general practice, 2000–2016.
All skin cancer conditions combined, overall and by patient characteristics
Table 1 shows the rate of skin cancer-related conditions managed per 1000 general practice encounters, overall and by different patient and GP characteristics. In summary, the management rate of skin cancer-related conditions increased steadily with age to peak in the 70–74 age group; was higher in males, those living in regional and remote areas, people from lower area-based socioeconomic index areas, of English-speaking background, Veteran card holders and non-healthcare card holders. The skin cancer-related management rate was significantly higher for males (56.71 vs 41.88 for females per 1000 encounters), though females represented 52.95% of all skin condition encounters. The rate of skin conditions managed in general practice was significantly higher in Queensland (71.66 per 1000 encounters) than in any other state or territory, and was lowest in Victoria (36.58 per 1000 encounters). Male GPs (55.60 per 1000 encounters) and GPs aged 35–44 years (50.57 per 1000 encounters) managed skin cancer-related conditions at higher rates.
Rate of skin cancer-related conditions managed per 1000 general practice encounters, overall and by different patient and GP characteristics, BEACH study, 2000–2016
Skin cancer conditions managed overall and over time, by patient characteristics
Age
Skin cancer-related conditions were managed far more frequently at encounters with older patients and the type of condition managed varied greatly by age (figure 2A–C). Skin checks and nevi represented a large proportion of skin cancer-related encounters managed among younger people aged <40 years but only a small proportion among people at older ages (figure 2A). People aged <40 years had the highest management rates for nevi per 1000 encounters, whereas people aged 30–69 years had the highest rates of skin checks (figure 2C). Management rates for keratinocyte cancers rose steeply from age 30–34 to 85–89 age groups (figure 2C). Management rates for solar keratoses rose steeply from age 30 to 60 years, then plateaued and reduced after age 85 years (figure 2C). Management rates for melanoma were highest at ages 65–69 years. Comparing management rates over time from 2000–2004 to 2012–2016, the rates increased for skin checks, keratinocyte cancers, and skin lesions, especially for older age groups (figure 2C).
(A) Proportion of different skin cancer-related conditions managed in general practice, by age group, 2000–2016. (B) Management rate per 1000 encounters of all skin cancer-related conditions combined, by age group, 2000–2016 (C) Management rate per 1000 encounters of each skin cancer-related condition, by age group 2000–2016.
Sex
The sex-specific management rate per 1000 encounters for all years combined did not differ for males and females for benign skin neoplasms, was higher among females than males for nevi (5.48 vs 4.86) and higher for males than females for melanoma (1.47 vs 0.95), keratinocyte cancer (16.11 vs 9.11), solar keratosis (18.28 vs 11.5), skin checks (5.26 vs 4.74) and skin lesions (6.46 vs 5.96). The management rate increased over time from 2000–2004 to 2012–2016 for both males and females for keratinocyte cancers, skin lesions and skin check-ups, although for melanoma it only increased for females (0.73 to 1.14).
Other characteristics
The distribution of different skin conditions managed was fairly similar across the states (figure 3A). While management rates for the different skin conditions per 1000 encounters followed a similar pattern in each state and territory, those for solar keratosis and keratinocyte cancers were significantly higher in Queensland. Management rates were significantly higher in regional and remote locations for most skin conditions except for nevi, benign skin neoplasms and skin checks. Over time, the management rate of skin conditions overall increased, particularly in the Australian Capital Territory, New South Wales and Victoria (figure 3B,C and online supplemental figure 1). Specifically, melanoma management rates significantly increased in major cities, New South Wales and Queensland; whereas management of skin lesions, keratinocyte cancers and skin checks increased significantly in all remoteness classes, and most states and territories (online supplemental tables 2 and 3).
(A) Proportion of different skin cancer-related conditions managed in general practice, by state/territory, 2000–2016. (B) Management rate per 1000 encounters of all skin cancer-related conditions combined, by state/territory, 2000–2016. (C) Management rate per 1000 encounters of all skin cancer-related conditions, by residential remoteness, 2000–2016. ACT, Australian Capital Territory; NSW, New South Wales; NT, Northern Territory; QLD, Queensland; SA, South Australia; TAS, Tasmania; VIC, Victoria; WA, Western Australia.
The management rates per 1000 encounters were greater with higher area-level socioeconomic advantage for skin checks, nevi and benign skin neoplasms, whereas lower area-level socioeconomically disadvantaged patients had higher management rates for keratinocyte cancer, melanoma, solar keratosis and skin lesions (online supplemental figure 2).
Skin cancer conditions managed by GP characteristics (rate and proportion)
Skin cancer-related conditions were most commonly managed by GPs aged 35–44 years (table 1) and the mean GP age over the study period ranged from 50.0 to 53.7 years. Over time, management rates increased particularly for GPs aged ≥45 years (figure 4A). There were more participating male GPs, ranging between 55.1% and 67.5% throughout the study, which is representative of the wider distribution of GP sex in the community; and management rates higher for male GPs than female GPs (figure 4B). Over time, the management rates increased for both male and female GPs (by 14.68 and 9.98 per 1000 encounters, respectively, figure 4B). Male GPs reported more encounters with keratinocyte cancers and solar keratosis, whereas female GPs reported more encounters with skin lesions. There was no difference by GP sex in management rates for benign skin neoplasms, nevi or skin checks (figure 4C). In a multivariable analysis, GP age (35–44 years vs ≥65 years; adjusted OR (AOR) 1.71, 95% CI 1.54 to 1.90) and GP sex (male vs female; AOR 1.14, 95% CI 1.08 to 1.21) remained significantly associated with a skin cancer-related problem being managed at an encounter, after accounting for time period and patient characteristics.
(A) Management rate per 1000 encounters of all skin cancer-related conditions combined, over time and by GP age group, 2000–2016. (B) Management rate per 1000 encounters of all skin cancer-related conditions combined, over time and by GP sex, 2000–2016. (C) Management rate per 1000 encounters of each skin cancer-related condition, by GP sex, 2000–2016. GP, general practitioner.
Discussion
In this Australian representative sample of general practice clinical activity encounters, we found a spectrum of skin cancer-related conditions managed, with the highest to lowest frequency being solar keratosis, keratinocyte cancer, other skin lesion, nevi, skin check, benign skin neoplasm and melanoma. Management rates increased over time for most skin cancer-related conditions and differed according to patient and GP characteristics.
The high and increasing rates of general practice encounters for skin cancer-related conditions reflect Australia’s latitude gradient, high exposure to ultraviolet radiation, predominantly fair-skinned people and ageing population.17 A study using data from the QSkin cohort and Medicare reported that 89% of excisions for keratinocyte cancer in Australia were performed by primary care practitioners,10 and data from the Tasmanian Cancer Registry showed that age-specific incidence rates of keratinocyte cancer increase with age, particularly for those aged 80 years and above.18 Solar keratosis (actinic keratosis), the most common skin cancer-related condition managed, is a marker of cumulative sun damage and some may transform into invasive SCC.19 Thus, prevention of skin cancer through sun protection is important at all ages.
The highest management rates for melanoma were for patients aged 65–69 years, consistent with the median age of diagnosis in Australia.6 Management rates for melanoma increased slightly over time, whereas cancer registry data have shown a decreasing age-specific incidence of invasive melanoma under 40 years of age, and considerable increase in melanoma incidence rates over time for older males and in situ disease.20 Although there have been no observational studies or randomised controlled trials conducted to examine melanoma overdiagnosis, an Australian study examining Australian Institute of Health and Welfare (AIHW) data reported that in situ melanomas accounted for most overdiagnosed melanomas.21
Patient characteristics associated with higher management rates for skin cancer-related conditions were older ages, male, living in Queensland or in regional or remote areas, with lower area-based socioeconomic status, English-speaking background and Veteran card holders. The higher rates in Queensland, at older ages and for males reflect their higher skin cancer incidence,1 and have been reported in previous analyses of the BEACH dataset.7–9 The lower rates among people of non-English-speaking background reflects darker skin or living in a different country as a child. Veteran card holders likely reflect an older and highly sun-exposed population. The other factors identified may reflect limited access to dermatology services for people living in regional and rural areas and in areas of lower socioeconomic status, leading more people in those areas to access skin cancer-related services in general practice. A previous population-based study found that people living in rural areas were less likely to be recommended a clinician-led skin surveillance programme than those living in urban areas.22
Australian Clinical Practice Guidelines (similar to many other countries)23 currently advise clinicians to assess patients opportunistically for skin cancer, or when concerned about a specific skin lesion, and only high-risk individuals are recommended to undertake regular skin examinations.24 Our results indicate an increase in skin checks in general practice over time, which is consistent with national survey data.25
Strengths and limitations
Major strengths of this study include the large Australian representative sample of general practice encounters (consultations). Representativeness of the GP sample was validated at each recruitment period. The data collection form allowed for up to four conditions managed in an encounter to be recorded, although only 3.2% of encounters had four problems managed in 2015–2016. These data on the actual condition being managed in general practice encounters are not available through the Medicare Benefits Schedule or administrative data collections. A limitation was the cross-sectional nature of the study, as we could not follow patients over time to examine the number of repeated consultations, which are known to be common,26 nor any skin cancer-related outcomes. The reported conditions were also not diagnostically verified, and data were not available for other skin cancer risk factors such as naevus counts and personal or family history of skin cancer. It was also not possible to separate the type of melanoma (in situ vs invasive) managed, nor the type of skin check (eg, total body or specific body site).
Conclusion
These findings show the spectrum and burden of skin cancer-related conditions managed in general practice in Australia. The most frequently managed skin cancer-related condition encountered in general practice was solar keratosis, followed by keratinocyte cancers, and rates increased over time. Management rates of skin cancer-related conditions varied considerably across different patient subgroups, and overall rates were higher for patients who were older, male and living in outer regional/remote regions or more disadvantaged areas. These results can guide GP education, policy and interventions to optimise skin cancer prevention and management.
Data availability statement
All data relevant to the study are included in the article or uploaded as online supplemental information. Data were obtained from the Bettering the Evaluation and Care of Health (BEACH) study team, who can be contacted for data sharing requests: christopher.harrison@sydney.edu.au.
Ethics statements
Patient consent for publication
Ethics approval
Human Ethics Committee of the University of Sydney (2012/130) and the Health Ethics Committee of the Australian Institute of Health and Welfare for the years they collaborated (2000-2011).
Acknowledgments
We thank Professor David Whiteman (QIMR Berghofer Medical Research Institute) for providing feedback on the paper and Professor Helena Britt (The University of Sydney) as the Chief Investigator of the BEACH program and for helpful comments.
Supplementary materials
Supplementary Data
This web only file has been produced by the BMJ Publishing Group from an electronic file supplied by the author(s) and has not been edited for content.
Footnotes
GR-M and KM are joint first authors.
Contributors AEC conceived the study aim and is responsible for the overall content as the guarantor; KM and CH conducted statistical analysis; AEC, GR-M, KM, CH, CW and Y-JK planned the analyses and scope; GR-M drafted the manuscript; all authors were involved in critically revising the manuscript and approved the final version.
Funding This work is supported by a project grant from the National Health and Medical Research Council of Australia (NHMRC; 1165936). AEC receives an NHMRC Investigator Fellowship (2008454). CH receives an NHMRC Early Career Fellowship (1163058).
Disclaimer The funders had no role in the study design, conduct, analysis, reporting, or the decision to submit the article for publication.
Competing interests None declared.
Patient and public involvement Patients and/or the public were not involved in the design, or conduct, or reporting, or dissemination plans of this research.
Provenance and peer review Not commissioned; externally peer reviewed.
Supplemental material This content has been supplied by the author(s). It has not been vetted by BMJ Publishing Group Limited (BMJ) and may not have been peer-reviewed. Any opinions or recommendations discussed are solely those of the author(s) and are not endorsed by BMJ. BMJ disclaims all liability and responsibility arising from any reliance placed on the content. Where the content includes any translated material, BMJ does not warrant the accuracy and reliability of the translations (including but not limited to local regulations, clinical guidelines, terminology, drug names and drug dosages), and is not responsible for any error and/or omissions arising from translation and adaptation or otherwise.