Original article
P. RodRíguez-gambetta1, m.g. moscoso-PoRRas2, a. tayPe-Rondan2
1 Faculty of medicine, universidad de san martín de Porres, Lima, Peru; 2 cRonIcas center of excellence for chronic diseases, universidad Peruana cayetano Heredia, Lima, Peru
Keywords
Sun protection • Sunscreen • Ordinal logistic regression
Summary
63.2% were female, 9.3% (females more than males) responded that a sunburn was worth it to look tan, and 38.1% always or almost always used sunscreen during the summer. Factors associ- ated with sunscreen use in the ordered logistic adjusted regression were male sex (OR = 0.50, IC95% = 0.34-0.86), participation in photo-protection workshops within the last year (OR = 2.40, IC95% = 1.28-4.37), and having somebody to remind them the use of sunscreen during the last three months (OR = 3.80, IC95% = 1.28-11.20).
Regulated sun exposure is beneficial to human beings because it prevents autoimmune diseases, helps produce vitamin D3, is beneficial for certain skin diseases such as psoriasis, and increases the serum levels of endorphins [1]. However, excessive sun exposure is related to the develop- ment of skin cancer, skin damage, photoaging, eye prob- lems, DNA mutations, and immune system damage [2].
Skin cancer is the major consequence of excessive sun exposure [3, 4]. According to the World Health Organi- zation (WHO), one of every three cancers detected in the world is a skin cancer [5]. As such, WHO recommends many photo-protective methods such as: seeking shade, use of sunscreen, skin-covering clothes, hats, and sun- glasses with UV filters [6].
Up to 80% of the radiation absorbed during one’s entire life is absorbed during childhood and adolescence [7, 8]. So, the best way to prevent the consequences of exces- sive sun exposure, including skin cancer, is to promote regular use of photoprotective methods from early ag- es [3, 4].
Use of sunscreen is one of the most recommended pho- toprotective methods. Unfortunately, it is frequently sub-optimally utilized, especially among adolescents and young adults [9]. Use of sunscreen in teenagers and
young adults has been evaluated in several studies where the prevalence fluctuates between 26% and 78% [10-12] It has been found that sunscreen use is related to some characteristics such as female sex, adult supervision, habits ingrained during childhood, prior awareness, pre- vious sunburns, expertise in the topic, previous use of tanning beds, warmer climates, and skin color [12-16]. However, these factors are context-dependent, so they can vary between regions.
Little has been described about these factors in Latin America [14, 17]. This lack of information hinders the design and enhancement of public policies aimed to pro- mote the use of photoprotective methods in young peo- ple, in order to prevent a variety of skin diseases, includ- ing skin cancer. Thus, the aim of this study is to assess the factors associated with the regular use of sunscreen in university medical students.
During April 2014, we conducted a descriptive study among first year medical students from the Universidad de San Martín de Porres (USMP). The USMP is a pri- vate university located in Lima, the capital city of Peru.
Students are usually middle class and come from all over the country.
Participants were all first year medical students who were enrolled according to a USMP database. By 2014, a total of 420 students were registered at the university. We perform the survey in those who agreed to partici- pate in the study after reading an informed consent. Par- ticipants whose surveys were less than 80% complete were excluded from the analyses.
Prior to the completion of this study, we obtained proper approval from the USMP ethics committee (IRB). We developed a consent form and survey based on the cur- rent literature. Both formats were posted on the USMP “virtual classroom”, so all first-year students could ac- cess both documents with a personalized password.
We approached first-year students during class periods in the computer lab to request their participation. The re- searchers were present during the survey completion to answer participants’ questions. Students unable to take the survey during their class period were granted the opportu- nity to complete it outside class hours.
Use of sunscreen
The use of sunscreen was measured by the statement: “during the last summer, when you were out in the sun, you used sunscreen…”, and the options: “never, almost never, sometimes, almost always, or always”. Later, this variable was categorized into three categories (Never/ Almost never, Sometimes, and Always/Almost always) to perform the ordinal logistic regression.
For the record, Peruvian summer occurs during January- March, and the survey was completed during April.
Other variables
The survey included five sections: demographic data (sex, age, place of birth, diagnosed skin disease, familiar or known person with skin cancer), self-identified skin phototype according to the Fitzpatrick classification (18), attendance to a photoprotective workshop, having someone remind you to use sunscreen in the last three months, knowledge of sun protection, attitudes regard- ing sun exposure, and assessment of usual photo-protec- tive methods (use of sunglasses with UV filters, hats or caps, umbrellas and long sleeves).
Data from the surveys were extracted from the virtual classroom, and exported into a Microsoft Excel data- base. Subsequently, surveys with less than 80% comple- tion were eliminated from the database.
Data was analyzed using STATA v13 (StataCorp, Col- lege Station, TX, US). For descriptive analysis, we used frequencies and percentages. For bivariate analysis, we
used Chi-squared tests with level of significance of 5% or Fisher’s exact test when expected frequencies in con- tingency tables were less than five.
Finally, as the outcome variable (sunscreen use) had an ordinal level of measurement, we used crude and ad- justed ordinal logistic regression after testing the pro- portional odds assumption to determine the associated factors. Adjusted regression included all variables tested in the crude analysis.
Participation in this study was voluntary, as stated in the consent form. To ensure the anonymity of the partici- pants, personal data (such as names, numbers of identity documents, and so on) were not requested. Moreover, the database was handled only by the researchers.
We requested the participation of all 420 first-year medi- cal students enrolled in the USMP in 2014, from which 321 (76.4%) took the survey. After quality control, 22 surveys were eliminated for being incomplete; leaving 299 (71.2%) surveys for analysis.
Univariate analysis reveals that 53.5% of the partici- pants were less than 18 years old, 63.2% were female, and 67.2% were born in Lima (capital city of Peru). With respect to the skin phototype, 46.1% had phototypes I, II or III, and 40.5% had phototype IV. With respect to the personal and familiar history, 15.7% had a skin disease, and 8.0% had a family member with known skin cancer (Tab. I).
Around 97.0% of the participants correctly answered that solar radiation is a major cause of skin cancer, but only 72.9% correctly answered that a sunscreen of SPF 15 is not better than one of SPF 30, moreover, only 23.1% correctly answered that on a cloudy day it is also necessary to use the sunscreen (Tab. II).
Regarding perceptions, 87.0% of the participants affirm that it is worth to use sunscreen to avoid future health problems, 18.2% believe that tan people look more at- tractive, and 9.3% responded that it is worth to get a sun- burn to look tan. This last perception was higher among females than males (p = 0.021).
With respect to the use of photoprotective methods, we found that the respondents always or almost always walked in the shade (66.9%), used sunscreen (38.1%), and wore long pants (30.1%). The use of sunscreen and long pants were higher among females than males (p = 0.010 and p = 0.011, respectively) (Tab. III).
Factors directly associated with a higher use of sun- screen in the ordered logistic adjusted regression
Tab. I. demographic data in first-year medical students at a private university in Lima, peru 2014 (N = 299).
Tab. II. Knowledge about solar exposure and the use of sunscreen in first-year medical students at a private university in Lima, peru 2014.
Knowledge | Yes N (%) | Do not know N (%) | No N (%) |
Solar radiation is a major cause of skin cancer? | 290 (97.0) | 6 (2.0) | 3 (1.0) |
A person with dark skin also needs to use sunscreen? | 289 (96.7) | 4 (1.3) | 6 (2.0) |
The use of sunscreen prevents skin cancer? | 276 (92.3) | 5 (1.7) | 18 (6.0) |
A sunscreen of SpF 15 is better than one of SpF 30? | 22 (7.4) | 59 (19.7) | 218 (72.9) |
On a cloudy day it is also necessary to use the sunscreen? | 69 (23.1) | 17 (5.7) | 213 (71.2) |
When using sunscreen, Can you expose to the sun without risk? | 70 (23.4) | 11 (3.7) | 218 (72.9) |
Characteristics | N (%) |
Age | |
< 18 years old | 160 (53.5) |
18-19 | 112 (37,5) |
20 or more | 27 (9,0) |
Sex | |
Female | 189 (63.2) |
male | 110 (36.8) |
place of birth | |
peru: Lima City | 201 (67.2) |
peru: Other | 81 (27.1) |
Foreign | 17 (5.7) |
Fitzpatrick Skin phototype | |
I-III | 138 (46.1) |
Iv | 121 (40.5) |
v- vI | 40 (13.4) |
diagnosed skin disease | |
No | 252 (84.3) |
yes | 47 (15.7) |
Familiar or known with skin cancer | |
No | 275 (92.0) |
yes | 24 (8.0) |
have you ever attended to a workshop about photoprotective methods? | |
Never | 181 (60.5) |
yes / Long ago | 66 (22.1) |
yes / This year | 52 (17.4) |
did somebody remind you to use sunscreen in the last three months? | |
Never | 4 (1.3) |
during childhood | 11 (3.7) |
during the last months | 11 (3.7) |
Both | 273 (91.3) |
Characteristics | N (%) |
Age | |
< 18 years old | 160 (53.5) |
18-19 | 112 (37,5) |
20 or more | 27 (9,0) |
Sex | |
Female | 189 (63.2) |
male | 110 (36.8) |
place of birth | |
peru: Lima City | 201 (67.2) |
peru: Other | 81 (27.1) |
Foreign | 17 (5.7) |
Fitzpatrick Skin phototype | |
I-III | 138 (46.1) |
Iv | 121 (40.5) |
v- vI | 40 (13.4) |
diagnosed skin disease | |
No | 252 (84.3) |
yes | 47 (15.7) |
Familiar or known with skin cancer | |
No | 275 (92.0) |
yes | 24 (8.0) |
have you ever attended to a workshop about photoprotective methods? | |
Never | 181 (60.5) |
yes / Long ago | 66 (22.1) |
yes / This year | 52 (17.4) |
did somebody remind you to use sunscreen in the last three months? | |
Never | 4 (1.3) |
during childhood | 11 (3.7) |
during the last months | 11 (3.7) |
Both | 273 (91.3) |
were: participation in at least one workshop about photoprotective methods in the last year (OR = 2.37, IC95% = 1.28-4.37) and having somebody to remind them the use of sunscreen during the last summer (OR = 3.78, IC95% = 1.28-11.21). While male sex
(OR = 0.54, IC95% = 0.34-0.86) was inversely associ- ated (Tab. IV).
Tab. III. perceptions and practices about solar exposure and photoprotective methods in first-year medical students at a private university in Lima, peru 2014.
Total N = 299 | Male N = 110 | Female N = 189 | p* | |
perceptions (Agree with) | ||||
It is worth to use sunscreen to avoid future health problems | 260 (87.0) | 96 (87.3) | 164 (86.8) | 0.526 |
Tan people is more attractive | 54 (18.2) | 24 (21.8) | 30 (15.9) | 0.129 |
It is worth it to get a sunburn to look tan | 28 (9.3) | 5 (4.6) | 23 (12.2) | 0.021 |
Tan people is more healthy | 20 (6.7) | 4 (3.6) | 16 (8.5) | 0.082 |
practices during the last summer (Always/Almost always) | ||||
Walk in the shadow | 200 (66.9) | 73 (66.4) | 127 (67.2) | 0.491 |
Sunscreen | 114 (38.1) | 32 (29.1) | 82 (43.4) | 0.010 |
Large pants | 90 (30.1) | 24 (21.8) | 66 (34.9) | 0.011 |
Sunglasses with Uv filters | 86 (28.8) | 25 (22.7) | 61 (32.3) | 0.051 |
Not going out in the hours of higher radiation | 86 (28.8) | 28 (25.5) | 58 (30.7) | 0.203 |
hats or caps | 53 (17.7) | 25 (22.7) | 28 (14.8) | 0.059 |
Umbrella | 37 (12.4) | 11 (10.0) | 26 (13.8) | 0.223 |
Long sleeves | 24 (8.0) | 11(10.0) | 13 (6.9) | 0.228 |
* Fisher’s exact test
Tab. IV. Factors associated with the use of sunscreen in first-year medical students at a private university in Lima, peru 2014.
Characteristics | Use of sun screen N (%) | Crude model | Adjusted model* | ||||||
Never/ Almost never | Sometimes | Always/ Almost always | Or | IC 95% | p | Or | IC 95% | p | |
Age | |||||||||
< 18 years | 31 (19.4) | 70 (43.7) | 59 (36.9) | ref. | ref. | ||||
≥ 18 years | 37 (26.6) | 47 (33.8) | 55 (39.6) | 0.92 | (0.60-1.40) | 0.700 | 0.82 | (0.53-1.27) | 0.383 |
Sex | |||||||||
Female | 33 (17.5) | 74 (39.1) | 82 (43.4) | ref. | ref. | ||||
male | 35 (31.8) | 43 (39.1) | 32 (29.1) | 0.50 | (0.32-0.78) | 0.002 | 0.54 | (0.34-0.86) | 0.009 |
Fitzpatrick Skin phototype | |||||||||
I-III | 24 (17.4) | 53 (38.4) | 61 (44.2) | ref. | ref. | ||||
Iv | 32 (26.4) | 49 (40.5) | 40 (33.1) | 0.61 | (0.39-0.96) | 0.035 | 0.67 | (0.41-1.09) | 0.103 |
v-vI | 12 (30.0) | 15 (37.5) | 13 (32.5) | 0.56 | (0.29-1.07) | 0.080 | 0.58 | (0.30-1.14) | 0.115 |
diagnosed skin disease | |||||||||
No | 59 (23.4) | 95 (37.7) | 98 (38.9) | ref. | ref. | ||||
Si | 9 (19.2) | 22 (46.8) | 16 (36.0) | 0.96 | (0.55 - 1.70) | 0.899 | 1.00 | (0.55-1.78) | 0.971 |
Familiar or known with skin cancer | |||||||||
No | 60 (21.8) | 110 (40.0) | 105 (38.2) | ref. | ref. | ||||
Si | 8 (33.3) | 7 (29.2) | 9 (37.5) | 0.75 | (0.34 - 1.68) | 0.489 | 0.8 | (0.34-1.71) | 0.509 |
have you ever attended to a workshop about photoprotective methods? | |||||||||
Never | 47 (25.9) | 70 (38.7) | 64 (35.4) | ref. | ref. | ||||
yes/ Long ago | 14 (21.2) | 31 (47.0) | 21 (31.8) | 1.01 | (0.60 - 1.70) | 0.954 | 1.00 | (0.59 - 1.71) | 0.983 |
yes/ In the last year | 7 (13.5) | 16 (30.8) | 29 (55.7) | 2.34 | (1.29 - 4.27) | 0.005 | 2.37 | (1.28 - 4.37) | 0.006 |
did somebody remind you to use sunscreen during the last summer? | |||||||||
No | 9 (60.0) | 3 (20.0) | 3 (20.0) | ref. | ref. | ||||
yes | 59 (20.8) | 114 (40.1) | 111 (39.1) | 1.56 | (0.49 - 2.62) | 0.004 | 3.78 | (1.28 - 11.21) | 0.016 |
*Adjusted model include every variable presented
In this study, we found that 97.0% of the participants knew about the relationship between sun exposure and skin can- cer. These results are consistent with other studies com- pleted in Australia where 80% of teenagers were compe- tent regarding the dangers of sun exposure [16], and with research made in United States of America (USA), where 89% of the adolescents knew about the association between unprotected sun exposure and skin cancer [19].
Fewer participants answered correctly about adequate sun- screen use: 71.2% answered that on a cloudy day it is not necessary to use the sunscreen, and 7.4% answered that a sunscreen of SPF 15 is better than one of SPF 30. These percentages are similar to other studies [19], and reflect that information regarding correct sunscreen use is not yet widely dispersed. These results suggest the necessity to im- prove population-level knowledge on this subject, as pre- vious studies have shown the positive association between high knowledge and a lower sunburn incidence [13].
The perception that it is worth to get a sunburn to look tan was higher among females than males. Results
were similar with other studies [13, 16]. This may be due to the arraigned social perceptions of beauty and fashion, which are especially strong in female adoles- cents [20, 21]. Educational campaigns must take this into consideration and make appropriate recommenda- tions [22].
The most commonly used photoprotective methods were walking in the shade, use of sunscreen, and the use of long pants. Nevertheless, sunscreen was used “always” or “almost always” by only 38.1% of the population. These results are consistent with previous data, where only 31.4% of the adolescents used sunscreen frequent- ly [19].
Nearly a third of the participants used sunglasses with UV filters “always” or “almost always”. Similar re- sults found in other studies was the use of sunglasses (32.2%) as one of the most common sun-protection behaviors [19]. Although not statistically significant (p = 0.051), our findings suggest that women are more likely to use sunglasses (32.3%) than with men (22.7%). These results were consistent with previous studies, where men use sunglasses less often [16]. This could re- flect a difference in sun protection awareness, or in fash- ion customs, between males and females.
In the multiple regression analysis, a higher use of sun- screen was associated with female sex. This result is similar to other studies [13, 16], and could be explained by differences in cultural roles between young males and females. Women are more concerned with personal care and skin rotection than men [23].
Attending a sunscreen workshop in the last year was also associated with increased sunscreen use. Other studies found that adequate educational campaigns could eradi- cate myths and improve the quality of sunscreen use among young people [15, 17].
Other protective factor was having a person who has re- minded them to use to use sunscreen in the last three months. In general, it seems that one of the biggest barri- ers hindering sunscreen use is forgetting to apply it [24] and lack of habit [14].
Our findings suggest that it is necessary to organize sunscreen educational activities for middle class urban children and adolescents. These activities should include information concerning the correct sunscreen use, and sex-specific recommendations, such as avoid tanning for women and use of photoprotective methods for men. These activities could be implemented in schools, uni- versities, and recreational settings [25].
Although not all young people have somebody to re- mind them about this topic, there are new methods to inform youth about sun protection (i.e., text messages or Smartphone applications) , which have already been used effectively [24]. These methods should be tested and implemented in young Peruvian population.
Nevertheless, the participants of this study are urban middle-class medical students. Therefore, our findings cannot be extrapolated to populations of lower socioeco- nomic status or rural dwellers who probably have dif- ferent challenges in accessing educational and reminder activities that help to reinforce healthy habits.
The present study has some limitations: first, it is pos- sible that participants, well-educated medical students, have a greater interest and knowledge-fund than the general Peruvian population. Moreover, the use of sun- screen as well as other variables were collected through an electronic survey, which are subjected to recall bias, as participants surveyed are in their first years of study, so we believe that their knowledge is not very different from that of other university freshmen.
In conclusion, our findings show that the main factors related to a higher sunscreen use in our population are being female, having attended safe-sun workshops, and having a person who reminds them to use sunscreen. Moreover, perceptions and practices related solar ex- posure and photoprotective methods differ according
to sex. These results should be taken into consideration when developing educational programs aimed at young middle class urban populations.
Acknowledgements
Authors wish to thank Elizabeth Abbs for her assistance in the manuscript redaction. Also, we would like to thank the Universidad de San Martín de Porres staff that kindly allowed us to collect data through their virtual database.
Authors declared they have no conflicts of interest re- garding the content of this article.
The present study was self-funded. ORCID
PR-G: orcid.org/0000-0002-6660-059X MGM-P: orcid.org/0000-0001-9518-4241 AT-R: orcid.org/0000-0001-8758-0463
PR-G and AT-R contributed to the conception and design of this study. PR-G planned and performed data collec- tion and prepared the first manuscript draft. AT-R and MGM-P provided feedback for all the manuscript ver- sions. MGM-P and AT-R performed the statistical analy- ses. All authors revised and approved the final version of the manuscript.
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n Received on March 6 , 2016. Accepted on June 21, 2016.
n Correspondence: Alvaro Taype-Rondan, CRONICAS Center of Excellence for Chronic Diseases, Universidad Peruana Cayetano Heredia, Lima, Peru, Avenida Armendáriz 497, Miraflores, Lima 18, Peru - Tel. +51 970001517 - E-mail: alvaro.taype.r@upch.pe