Kiến thức, thái độ và hành vi sử dụng kem chống nắng của bệnh nhân sạm da tại Việt Nam

Một đề tại lạ và độc về kiến thức sử dụng kem chống nắng của bệnh nhân sạm da tại Việt Nam. Đề tài cho thấy: The study showed that patients with melasma had low knowledge on sun exposure and sunscreen use. On the contrary, attitude and behavior of sunscreen use were relative high. Gender play an important role in determining knowledge, attitude and behavior of patients. Other factors including sunexposed occupation, educational, family history of melasma and recurrence of melasma were also have influences on knowlegde, attitude and behavior of participants. Thus, a education program on sunscreen use should be implimented in the near future to improve knowledge, attitude and enhance behavior of patients with melasma.

Meiho University Graduate Institute of Health Care

Thesis

KNOWLEDGE, ATTITUDE AND SUNSCREEN USE BEHAVIOR AMONG PATIENTS WITH MELASMA IN VIETNAM

Graduate student: Phạm Hoài Thu Supervisor: Dr Neoh Choo Aun

July 2015 美美美美美美 Meiho University

美美美美美美美 Graduate Institute of Health care

美美美美 Master Thesis

KNOWLEDGE, ATTITUDE AND SUNSCREEN USE BEHAVIOR AMONG PATIENTS WITH MELASMA IN VIETNAM

研研研研Phạm Hoài Thu

研研研研研Dr Neoh Choo Aun

2015 美 06 美

KNOWLEDGE, ATTITUDE

AND SUNSCREEN USE BEHAVIOR AMONG PATIENTS WITH MELASMA IN VIETNAM

Meiho University

In partial fulfillment of the requirement for the degree of

Master of Health Care

July 2015

Abstract

Background: Melasma, a localized hyperpigmentation, affects millions of

people worldwide The Dermatology Hospital in Ho Chi Minh city is thebiggest hospital specializing in treatment of dermatological conditions,including melasma After a course of laser therapy, patients were counseled touse sunscreen to prevent the recurrence of melasma and revisit the hospital afterone-month use of sunscreen to check their conditions Although no official dataabout the rate of recurrence among affected patients, many recurrent cases havebeen documented in practice Such situation raises questions involving whether

or not patients used sunscreen after laser therapy, how they applied sunscreen intheir daily life and to what extent they are knowledgeable about melasma andproper use of sunscreen to protect their body from recurrence of melasma

Objective: The aim of the study was to find out the knowledge, attitude and

behavior related to sunscreen application among melasma patients who hadreceived laser therapy

Methods: A cross-sectional hospitalized-based study is undertaken between

April and May 2015 in Ho Chi Minh city, Vietnam A sample of 123 patients

questionnaire The significance of the results was assessed by t-test, ANOVAtest and Chi-Square test at p-value of 0.05 using SPSS version 16.

Results: There were 123 participants enrolled in the study; of which,

80.49% was female There were 60.61% female patients had a history ofpregnancy Most of participants in the study had the age from 20 to 49 years ofage (87.81%) and only 1.63% of participants aged over 60 There were 63.41%patients had married, while 32.52% were unmarried Kinh was the predominantethnic in this study (93.5%)

The total knowledge mean score of participants was relative low, yielding1.96 ± 1.09 (0-4) The total attitude score among patients was relative high(30.53 ± 4.16) The proportion of using sunscreen among participants was78.05% The analysis showed that gender and occupation had significantassociations with knowledge about sunscreen use among patients with melasma(p< 0.05) Male had lower attitude score than female and this deference wasstatistical significant (p< 0.001) Patients who were illiterate and finishedelementary school, high school, university gain the highest score compared toother education groups (p=0.03) Between gender and sunscreen use had asignificant association (p< 0.001) in which female patients practiced sunscreenuse higher than male patients elative with melasma and recurrence of melasma

were two factors those had statistical significant associations with behavior ofsunscreen use among patients (p=0.04 and p =0.005).

Conclusion: The study showed that patients with melasma had low

knowledge on sun exposure and sunscreen use On the contrary, attitude andbehavior of sunscreen use were relative high Gender play an important role indetermining knowledge, attitude and behavior of patients Other factorsincluding sun-exposed occupation, educational, family history of melasma andrecurrence of melasma were also have influences on knowlegde, attitude andbehavior of participants Thus, a education program on sunscreen use should beimplimented in the near future to improve knowledge, attitude and enhancebehavior of patients with melasma

First and foremost, I would like to send from bottom of my heart my thanks

to my supervisor, Dr Neoh Choo Aun., for all encouragement, support andfeedback you gave to me Secondly, I would like acknowledge the endeless andprecious supports from other Meiho professors, who always facilitate mecomplete this thesis

I also would like to thank a lot to valuable supports by The Director Board

of Demartology Hospital during my studying and my thesis implimentation Forall patients who had participants in this study I send my special thanks to all ofyou for accepting me to use your information

Page

Appendix 1: The questionnaire

Appendix 2: The informed consent

Appendix 3: the Ethical Committee of certification

List of tables

Page

List of figure

Page

Chapter 1: Introduction

1.1 Statement of this research

Melasma, a localized hyperpigmentation, affects millions of peopleworldwide Although there are no global data about the prevalence of melasma,studies showed a wide variation in prevalence among countries worldwide Astudy in Brazil where high sun exposure is common showed that the prevalence

of melasma ranged from 5.9% to 9.1% in the different regions of the country(Sociedade Brasileira de Dermatologia SBD, 2006) Other studies in Nepal andSaudi Arabia reported melasma is one of the most frequent pigmentarydermatosis (Alakloby, 2005; Walker, Shah, Hubbard, Pradhan, & Ghimire,

2008) In United States, Halder et al (1983) confirmed melasma is a frequentpost-inflammatory hyperpigmentation among black population

Melasma has a significant impact on appearance, causing psychosocial andemotional distress, and reducing the quality of life of the affected patients.Studies indicated that patients with melasma experienced many distresses such

as frustration, dissatisfaction, low self-esteem, and embarrassment in their dailylife (Cestari, Hexsel, Viegas, Azulay, Hassun, Almeida, & et al, 2006; Purim &

Avelar, 2012) In addition, there are high expenditures related to medicaltreatments and procedures whose results do not always meet the expectations ofpatients (Handel, Miot, & Miot, 2014)

There are various treatment modalities of melasma have been establishedfor years including sunscreen products (Grimes, 2007; Pathak, Fitzpatrick, &Kraus, 1986; Scheinfeld, 2007), hydroquinone (Abramovits, Gover, & Gupta,

2005; Grimes, 1995; Gupta, Gover, Nouri, & et al, 2006; Lynde, Kraft, &Lynde, 2006; Victor, Gelber, & Rao, 2004), azelaic acid (Baliña & Graupe,

1991; Kakita & Lowe, 1998; Lowe, Rizk, Grimes, & et al, 1998; Sarkar, Bhalla,

& Kanwar, 2002) and other chemical therapies (Nerya, Musa, Khatib, & et al,

2004; Nerya, Vaya, Musa, & et al, 2003) However, with its recurrent andrefractory nature, the possibility of recurrence of melasma makes it become adifficult-to-treated pigmentary dermatosis Laser therapy is currently applied inmelasma treatment as a potential therapy since evidence showed itseffectiveness in decline of melasma recurrence (Jang, Lee, Kim, & Kim, 2011 ;

Kroon, Wind, Beek, van der Veen, Nieuweboer-Krobotová, Bos, &Wolkerstorfer, 2011 ; Wattanakrai, Mornchan, & Eimpunth, 2010) To optimalthe effectiveness of laser therapy, the combination of proper chemical treatmentand laser procedure is a recommended strategy for treatment of melasma

(Arora, Sarkar, Garg, & Arya, 2012 ).

1.2 Significance of this research

The Dermatology Hospital in Ho Chi Minh city is the biggest hospitalspecializing in treatment of dermatological conditions, including melasma It isestimated that about 1,200 patients with pigmentation disorders visited thehospital in 2013, of those 34% experienced melasma (Dermatology Hospital,

2013) Currently, laser treatment with subsequent sunscreen has been appliedfor three years and become a standard procedure in melasma treatment in thehospital After a course of laser therapy, patients were counseled to usesunscreen to prevent the recurrence of melasma and revisit the hospital afterone-month use of sunscreen to check their conditions Although no official dataabout the rate of recurrence among affected patients, many recurrent cases havebeen documented in practice Such situation raises questions involving whether

or not patients used sunscreen after laser therapy, how they applied sunscreen intheir daily life and to what extent they are knowledgeable about melasma andproper use of sunscreen to protect their body from recurrence of melasma.Surprisingly, there are not any studies explore this issue in the hospital setting

To answer all of these questions, I conduct this study

1.3 Aim of this research

The main aim of this study to find out the awareness and behavior related tosunscreen application among melasma patients who had received laser therapy.The specific objectives of this study therefore include:

1. Identify knowledge, attitude and behavior regarding sunscreen use among

1.5 Chapter summary

Melasma, a localized hyperpigmentation, affects millions of peopleworldwide Melasma has a significant impact on appearance, causingpsychosocial and emotional distress, and reducing the quality of life of theaffected patients The Dermatology Hospital in Ho Chi Minh city is the biggesthospital specializing in treatment of dermatological conditions, including

sunscreen to prevent the recurrence of melasma and revisit the hospital afterone-month use of sunscreen to check their conditions Although no official dataabout the rate of recurrence among affected patients, many recurrent cases havebeen documented in practice Surprisingly, there are not any studies explore thisissue in the hospital setting To answer all of these questions, this study isconducted.

Chapter 2: Literature Review

2.1 Introduction

In this chapter, definition of melasma was decribed firstly The second partintroduced epidemiology of melasma including prevalence and risk factors ofmelasma worldwide Management of melasma was the third part mentioned inthis chapter The final part focused on knowledge, attitude and behavior ofsunscreen use and factors that influence those interested variables

2.2 Definition of melasma

Melasma is a human melanogenesis dysfunction that results in localized,chronic acquired hypermelanosis of the skin It occurs symmetrically onsunexposed areas of the body, and affects especially women in menacme (Miot,Miot, Silva, & Marques, 2009)

The word melasma originates from the Greek root “melas”, which meansblack, and refers to its brownish clinical presentation The designations: “mask

of pregnancy”, liver spots, uterine chloasma, chloasma gravidarum, andchloasma virginum do not fully characterize the disease, nor are semanticallyappropriate, although the term “chloasma” (derived from the Latin chlóos and

the Greek cloazein: greenish) is still used in the medical literature (Bolanca,Bolanca, Kuna, Vuković, Tuckar, Herman, & et al, 2008; Miot, et al., 2009).

2.3 Epidemiology of melasma

2.3.1 Prevalence and incidence of melasma

Although there are no data about the global prevalence of melasma, studiesshowed a wide variation in prevalence among countries worldwide A studyfrom Brazil showed that melasma accounted from 5.9% to 9.1% ofmelanodermias in the different regions of the country (Sociedade Brasileira deDermatologia SBD, 2006) Another study conducted in Nepal with 546dermatological patients evidenced melasma as the fourth most frequentdiagnosis and the first most commonly reported pigmentary dermatosis (Walker,

et al., 2008) In addition, a retrospective study conducted in Saudi Arabia, whichanalyzed data from 1076 dermatology patients, also described melasma as thefourth most common dermatosis (Alakloby, 2005) Another study conductedwith 2,000 dermatological patients of black origin in Washington, DC, revealedthat the third most commonly-cited skin disorders were pigmentary problemsother than vitiligo Of these patients, the majority had a diagnosis ofpostinflammatory hyperpigmentation, followed in frequency by melasma(Halder, et al., 1983)

The incidence of melasma is not precisely known Changes occurred inrecent decades due to the increase in sun exposure time spent by the populationduring leisure and daily activities were not substantiated in studies (Souza,Fischer, & Souza, 2004).

2.3.2 Risk factors for melasma

It is believed that melasma occurs in all ethnic and population groups;however, epidemiological studies have reported higher prevalence among morepigmented phenotypes Melasma is common among Hispanic-Americans andBrazilians who live in inter-tropical areas, where there is greater exposure toultraviolet radiation (UVR) (Perez, Luke, & Rossi, 2011; Sheth & Pandya,

2011; S C Taylor, 2003) Among a Latino population resident in USA,prevalence of melasma was 8.8%, and 4.0% of respondents reported pastoccurrence of melasma (Werlinger, Guevara, González, Rincón, Caetano, Haley,

& et al, 2007)

A clear female predominance was observed in the reports of the disease AnIndian study found a less significant prevalence (6:1), whereas in Brazil andSingapore, there was also a clear female predominance: 39:1 and 21:1,respectively (Achar & Rathi, 2011; Goh & Dlova, 1999; Hexsel, Lacerda,Cavalcante, Machado Filho, Kalil, Ayres, & et al, 2013) In another study

conducted in India, an even greater discrepancy between men and women wasidentified: among 120 patients with melasma, 25.8% were men (Sarkar, Jain, &Puri, 2003).

Melasma occurs more frequently in pregnancy period A population-basedsurvey of 855 Iranian women reported among 39.5% respondents withmelasma, 9.5% were pregnant women (Edalatkhah, Amani, & Rezaifar, 2004)

A cross-sectional study in Southern Brazil identified melasma in 10.7% of 224pregnant women (Hexsel, Rodrigues, Dal'Forno, Zechmeister-Prado, & Lima,

2009) In about 40-50% of the female patients the disease is triggered bypregnancy or by the use of oral contraceptive 8% to 34% of women takingCOC (combined hormonal oral contraceptive) develop melasma, which wasalso reported after hormone replacement therapy (Wu, Lambert, Lotti,Hercogová, Sintim-Damoa, & Schwartz, 2012)

Intensity of sun expose may have an impact on the risk of development ofmelasma A study in India showed that the prevalence of melasma among paddyfield workers reached up 41% (Shenoi, Davis, Rao, Rao, & Nair, 2005).Scheinfeld et al (2007) also concluded that intensity of sun expose plays animportant role in the development of the disease

Since melasma results from a local change in pigmentation, it preferably

affects more strongly melanized phenotypes, and is mainly present inintermediate skin types III-V (Fitzpatrick classification) In a sample of 302Brazilian patients, 34.4% had skin type III, 38.4% had skin type IV and 15.6%had skin type V (Tamega Ade, Miot, Bonfietti, Gige, Marques, & Miot, 2013).

In Tunisia, a survey of 188 women showed that 14% had skin type III, 45% hadskin type IV and 40% had skin type V (Guinot, Cheffai, Latreille, Dhaoui,Youssef, Jaber, & et al, 2010) It is theorized that individuals with skin type Ifail to produce additional pigmentation, and individuals with skin type VIalready produce it at maximum efficiency; thus, skin types I and VI characterizephenotypes of stable pigmentation

2.4 Management of melasma

Melasma has been described as refractory to treatment because there is nocure and the condition tends to recur in susceptible individuals The standardmedical management of melasma includes broad-spectrum sunscreens typicallyused for prevention and various depigmenting agents, such as hydroquinone(HQ), tretinoin, azaleic acid, topical corticosteroids, kojic acid, and chemicalpeels (Grimes, 1995; Lynde, et al., 2006; Prignano, Ortonne, Buggiani, & et al,

2007)

2.4.1 Sunscreen application

Because solar radiation, particularly UVA and UVB, is known to increasethe risk of developing melasma or exacerbating existing disease, sunscreenproducts are essential for both prevention and management of melasma(Grimes, 2007; Pathak, et al., 1986; Scheinfeld, 2007) A broad-spectrum agent,containing both zinc and titanium (which have peaks of absorption in the UVAand UVB ranges, respectively), is recommended The sunscreen should alsohave a sun protection factor (SPF) higher than 45 Patients with melasma orthose who are at risk for melasma should be advised to use sunscreen daily,particularly under conditions of exposure (Grimes, 2007; Lynde, et al., 2006;

Scheinfeld, 2007)

Data from a number of recent trials indicate that corrective use of sunscreenmay also play a role in the management of melasma by improving the patient’squality of life and self-image while he or she is undergoing what may be aprotracted course of treatment Boehncke et al (2002) conducted a pilot study inwhich 20 female patients with a range of facial dermatoses (eg, acne, rosacea,vitiligo) were instructed by a cosmetician in the use of a corrective cosmetic.The mean index score of quality of life (reduced score indicates improvedquality of life) decreased from 9.2 at baseline to 5.5 at the end of 2 weeks ofmakeup use A similar outcome was observed in a study of 73 women with

severe facial pigmentary disorders (eg, melasma, acne, hypopigmentation,rosacea) (Balkrishnan, McMichael, Hu, & et al, 2005) These patients received

an application of a corrective cosmetic at the initial visit, along with a supply ofthe product and instructions on its use Assessments were conducted at baselineand at 2-week, 4-week, and 3-month follow-up visits on 63 patients using theSkindex-16, an evaluative instrument measuring self-reported burden of disease

At the 3-month end point, there was a 30% improvement in mean Skindex-16score (P < 001) The corrective cosmetic was well tolerated

2.4.2 Hydroquinone

Hydroquinone (1,4-dihydroxybenzene) is a hydroxyphenol; itspharmacodynamic action in the context of melasma appears to involvedisruption of melanin synthesis By inhibiting the action of the tyrosinaseenzyme, HQ prevents the enzymatic oxidation of tyrosine to dopa and, thus, thesubsequent conversion of dopa to melanin Other proposed effects of HQ inmelasma involve interference with DNA and RNA synthesis, local degradation

of melanosomes, and destruction of proliferating melanocytes (Abramovits, etal., 2005; Grimes, 1995; Gupta, et al., 2006; Lynde, et al., 2006; Victor, et al.,

2004)

Therapy with HQ at various concentrations (2%, 4%, and 5%) has been

described as the gold standard for melasma therapy Multiple clinical studieshave evaluated the efficacy and safety of HQ (Eespinal-Perez, Moncada, &Castanedo-cazares, 2004; Glenn, Grimes, Pitt, & et al, 1993; Sanchez, Pathak,Sato, & et al, 1981) However, side effects can be a concern with HQ, especially

at higher concentrations and particularly because dermatologists may prescribehigher, extemporaneously compounded concentrations of the agent Side effectsassociated with HQ include erythema, dermatitis, nail bleaching,postinflammatory hyperpigmentation, hypopigmentation of normal skin, andochronosis, which has been associated with prolonged use of highconcentrations of HQ (Findlay, Morrison, & Simson, 1975; Grimes, 1995;

Jordaan & Van Niekerk, 1991)

2.4.3 Alternative treatments for melasma

Azelaic Acid

Azelaic acid (AzA) is a naturally occurring nontoxic C9 dicarboxylic acidthat has demonstrated substantial biologic activity and pharmacodynamicproperties Beneficial results have been shown in a range of hyperpigmentationdisorders, including melasma and lentigo maligna, primarily through AzA’santiproliferative effects on hyperactive melanocytes and its inhibition oftyrosinase activity (Glenn, et al., 1993; Grimes, 2007; Gupta, et al., 2006) The

efficacy and safety of AzA for the treatment of melasma have been investigated

in randomized clinical trials (Baliña & Graupe, 1991; Kakita & Lowe, 1998;

Lowe, et al., 1998; Sarkar, et al., 2002)

Tretinoin

Tretinoin (retinoic acid) is an agent with activity in the regulation of celldifferentiation (Draelos, 2006) In the context of melasma treatment, tretinoinappears to interfere with tyrosinase induction and melanocyte differentiationleading to melanogenesis Depigmentary effects include dispersal ofkeratinocyte granules, interference with pigment transfer of melanosomes tokeratinocytes, and acceleration of epidermal turnover, shortening transit timefrom the basal layer (Grimes, 1995; Gupta, et al., 2006; Lynde, et al., 2006;

Menter, 2004) Tretinoin at various strengths (eg, 0.1%, 0.01%, 0.05%) has beenreported to be efficacious in melasma and is often a component in combinationtherapy regimens (Griffiths, Finkel, Ditrec, & et al, 1993; Grimes, 1995; Tadaki,Watanabe, Kumasaka, & et al, 1993)

2.4.4 Other chemical therapies

Topical corticosteroids have sometimes been used in the treatment ofmelasma, particularly when combined with HQ, tretinoin, or both (Torok,

2006) It has been hypothesized that corticosteroids may affect melanin

synthesis by inhibiting prostaglandin and cytokine production in the epidermis.Such a mechanism would suppress biosynthetic and secretory functions ofmelanocytes, thereby downregulating melanin production but not destroying themelanocytes, resulting in an outcome that could explain the rather short-livedbenefit of corticosteroid monotherapy (Abramovits, et al., 2005; Gupta, et al.,

2006) Chronic topical corticosteroid use is not encouraged because of theunfavorable side effect profile associated with even diluted concentrations ofthese agents Side effects attributable to topical corticosteroids include skinatrophy, telangiectasia, itching, acne and acneform eruptions, erythema, andperioral dermatitis (Abramovits, et al., 2005)

Chemical peels, such as glycolic acid and kojic acid, have also been used totreat hyperpigmentation disorders, particularly in those with lighter skin; the use

of chemical peels in darker-skinned patients has been associated withdepigmentation and hypopigmentation of normal adjacent skin (Grimes, 1995).The efficacy of glycolic acid (an α-hydroxy acid) may be mediated by a number

of mechanisms, such as stratum corneum thinning, melanin dispersal in thebasal layer of the epidermis, and enhancement of epidermolysis (Victor, et al.,

2004) Kojic acid, or 5-hydroxy-2-(hydroxymethyl)-4-pyrone, has alsodemonstrated efficacy in the treatment of melasma and other hyperpigmentary

disorders Kojic acid appears to work by inhibiting production of free tyrosinase(Garcia & Fulton, 1996; Halder, et al., 1983) However, kojic acid has also beenassociated with a relatively high incidence of contact dermatitis (Nakagawa,Kawai, & Kawai, 1995; Serra-baldrich, Tribó, & Camarasa, 1998).

Licorice extracts such as isoliquiritigenin (a chalcone) and glabrene areknown to inhibit tyrosinase; they may also disperse melanin and haveantioxidant/anti-inflammatory properties (Nerya, et al., 2004; Nerya, et al.,

2003) However, clinical trial data on the use of these agents in the treatment ofmelasma are scarce because licorice extract is expensive and the concentrationsused in most products are low (Amer & Metwalli, 2000)

2.4.5 Laser for treatment of melasma

Although many treatment modalities have been developed for melasma, itsmanagement still remains a challenge due to its recurrent and refractory nature.With the advent of laser technology, the treatment options have increasedespecially for dermal or mixed melasma

Various lasers that have been used for melasma (Goldberg, 1997) includeGreen light (flashlamp-pumped pulsed dye laser (PDL) (510 nm), frequencydoubled QS Nd:YAG (Q Switched Neodymium: Yttrium Aluminium Garnet-

532 nm), Red light (QS Ruby (694 nm), QS Alexandrite (755 nm)), and

Near-infrared: QS Nd:YAG (1064 nm) The green light lasers do not penetrate asdeeply into the skin as the other two groups owing to their shorter wavelengths.They are therefore effective only in the treatment of epidermal melasma Redlasers have longer wavelengths and thus may penetrate deeper into the dermis.Near-infrared laser has more advantages in its ability to penetrate more deeply

in the skin In addition, it may prove to be more useful in the treatment oflesions in individuals with darker skin tones (Goldberg, 1997)

2.5 Knowledge, attitudes and behavior related to sunscreen use

To my knowledge, there are not any studies investigating sunscreen useamong melasma population, especially patients who experienced laser treatmentfor melasma Instead, most of studies are interested in exploring the knowledge,attitude and behavior of sunscreen use among general population or specificpopulations such as children and their parent, student or young adults

2.5.1 Knowledge about sunscreen use

A Saudi Arab study on healthy adults showed that fifty six percent ofparticipants have an awareness of the relationship between sunburns and the risk

of skin cancer (Al Robaee, 2010) However this knowledge rate is low whencompared with similar surveys carried out in western communities

2.5.2 Sunscreen use behavior among general population

Different studies from many countries demonstrate a variation on sunscreenuse rate A study in Tanzania showed that using sunscreen was the secondpopular choice of sun protection methods among participants (71.9%)(Kagashe, Maregesi, & Mnyenye, 2013) A study in United States showed thatthe most widely used sun protection for children by parents is the use ofsunscreen (Robinson, Rigel, & Amonette, 2000 ) A study in Palestine showedthat the total sunscreen users were 118 (47.2%) (Naserzaid & Al-Ramahi, 2012).

In a survey from Northern Ireland, use of sunscreens was reported by 70% ofrespondents (Gavin, Boyle, Donnelly, Donnelly, Gordon, McElwee, & O'Hagan,

2011 ) However, a study in Saudi Arab showed that only 8.3% of the Saudiadult populations were using sunscreen regularly (Al Robaee, 2010)

A major problem with sunscreen use is the inadequate application by users.Previous studies have recorded poor compliance with recommendations ofregular application and reapplication of sunscreen (Dennis, Beane Freeman, &VanBeek, 2003; S R D Taylor, 2004) When the SPF of a sunscreen is beingtested, the protocol uses 2 mg/cm2 This amount, approximately three grams for

an adult or approximately equal to two finger lengths of sunscreen, is supposed

to be applied to eleven areas on the body, each covering nine percent of bodysurface However, it has been found that the amount that people usually apply to

their bodies is equivalent to only one third of the SPF of the sunscreen used (S.

R D Taylor, 2004) Many parts of the body are skipped when applyingsunscreen, including ears, neck, feet, and legs (Robinson, et al., 2000 )

According to WHO sunscreens should be applied liberally and re-appliedevery two hours, or after working, swimming, playing or exercising outdoors(World Health Organization, 2014) Most of individuals at all age know aboutthe risks of sun exposure such as sunburns, tanning, skin cancer and melasma,but the proper use of sunscreen products was not very clear to them Twostudies in Tanzania on albinism patients showed that although most of patientsknew about the risks of skin cancer as they expose highly to sunshine, theirpractice of sunscreen products are inappropriate (Kagashe, et al., 2013;

McBride & Leppard, 2002)

Females at all age group have been demonstrated that they have bettersunscreen use behavior than male counterparts (Banks, Silverman, Schwartz, &Tunnessen, 1992; Cottrell, McClamroch, & Bernard, 2005; Mermelstein &Riesenberg, 1992; Robinson, Rademaker, Sylvester, & Cook, 1997) According

to a report of NSW Health Department and The Cancer Council NSWA (2001),higher proportion of men (41.7%) than women (24%) rarely or never usedsunscreen Women were much more likely to have reported always wearing

sunscreen when in the sun (37.1%) A recent study in Saudi Arabia showed thatwomen were more likely than men to know about the hazards of sun exposureand were more likely to take protective measures including use of sunscreens(Al Robaee, 2010).

Between skin type and sunscreen use has a strong relationship A study inSaudi Arabia showed that the positive relationship found between sunscreen useand skin type 4 (Al Robaee, 2010) The Sun Smart evaluation in Victoria,Australia, reported that 46% of people who almost always used sunscreen hadbeen sunburned in the previous summer compared with only 31% of those whorarely used sunscreen (Dadlani & Orlow, 2008)

Sunscreen was much more likely to have been used by younger people, andthere was a gradual decline in use from 18 to 24 year olds to those aged 75years and over

Education also has strong relationship with use of sunscreen Past researchhas found that people of higher education levels and higher socio-economicstatus are more likely to use sunscreen (Robinson, et al., 2000 ) A study withparent to their children’s use of sunscreen showed that a significant relationshipwith the participants’ education level and always using sunscreen with theirchildren when playing outside (Megargell & Shive, 2006)

2.6 Chapter summary

Melasma is a human melanogenesis dysfunction that results in localized,chronic acquired hypermelanosis of the skin It occurs symmetrically onsunexposed areas of the body, and affects especially women in menacme.Although there are no data about the global prevalence of melasma, studiesshowed a wide variation in prevalence among countries worldwide Melasmahas been described as refractory to treatment because there is no cure and thecondition tends to recur in susceptible individuals The standard medicalmanagement of melasma includes broad-spectrum sunscreens typically used forprevention and various depigmenting agents, such as hydroquinone (HQ),tretinoin, azaleic acid, topical corticosteroids, kojic acid, and chemical peels To

my knowledge, there are not any studies investigating sunscreen use amongmelasma population, especially patients who experienced laser treatment formelasma Instead, most of studies are interested in exploring the knowledge,attitude and behavior of sunscreen use among general population or specificpopulations such as children and their parent, student or young adults

Chapter 3: Research Methodology

3.1 Introduction

In this chapter, research design and other methodological matters will bediscussed A research framework is developed to clarify all variables and theirrelations that will be investigated in the study Sampling issues such as samplesize, sampling criteria, and sampling procedure are also outlined Datamanagement is an important part of the chapter that focus on data collectingtool, data mining technique, and data analysis strategy

3.2 Research design

A cross-sectional hospitalized-based study is undertaken between April andMay 2015 in Demartology Hospital in Ho Chi Minh city

3.3 Research framework and hypotheses

Since the main aim of this study is to investigate sunscreen use behavioramong melasma patients and related factors affecting to their sunscreen use, it isnecessary to apply a behavioral change model to explain the behavior ofpatients Literature showed that numerous models or theories of behaviorchange have been developed in health education and health promotion To

sunscreen use behavior, we also searched literature for behavioral model used toexplain behaviors of certain populations Many studies on sunscreen activitiesapplied the Knowledge, Attitude and Behavior (KAB) or knowledge-attitude-practice (KAP) to describe the sunscreen use behavior It is important therefore

to review about this behavioral model

Knowledge, attitude, and behavior (KAB), also found in literature asknowledge-attitude-practice (KAP), is an important theoretical model of healtheducation, which asserts that behavior change is affected by knowledge andattitude (Schneider & Cheslock, 2003) Understanding the levels of Knowledge,Attitude and Practice will enable a more efficient process of awareness creation

as it will allow program to be tailored more appropriately to the needs of thecommunity In KAB, there are three components including knowledge, attitudeand behavior Knowledge is conceived as a set of understandings, knowledgeand of “science.” It is also one’s capacity for imagining, one’s way ofperceiving Attitude is a way of being, a position This is an intermediatevariable between the situation and the response to this situation It helps explainthat among the possible practices for a subject submitted to a stimulus, thatsubject adopts one practice and not another Practices or behaviors are theobservable actions of an individual in response to a stimulus

The KAB model proposes that behavior changes gradually As knowledgeaccumulates in a health behavior domain, changes in attitude are initiated Oversome period of time, changes in attitude accumulate, resulting in behavioralchange The change in attitude seems to be the motivational force, whileaccumulation of knowledge is the primary source of behavioral change.However, the accumulation of knowledge may also cascade into changes inattitudes, behaviors, or both

Based on the KAB theoretical model and other related studies, I alsoapplied KAB model as study framework to explore the knowledge, attitude andbehavior regarding sunscreen use among melasma patients after laser treatment

In this study framework, three main components including knowledge, attitudeand behavior are investigated Additionally, modifying factors includingdemographic variables are also included in the framework

Knowledge is defined as patients’ perceptions Knowledge investigated inthis study are divided into two groups: (1) knowledge about sun exposureincluding chronic effects and acute effects of sun exposure, time when UVradiations are strongest and (2) knowledge about sunscreen use including sunprotection factor (SPF) meaning, time interval of sunscreen use, time ofapplying sunscreen, and amount of sunscreen use

Attitude refers to what melasma patients think about sunscreen aftermelasma treatment Attitude in this study is made of three aspects includingeconomic, physical and emotional aspects The economic aspect tries to explorewhether or not patients think sunscreen use is affordable to them, while physicalaspect involves questions asking about physical impacts of sunscreen products

on patients’ skin Lastly, emotional aspect includes questions about feeling ofpatients about sunscreen use in their daily life

Sunscreen use behavior is defined as sunscreen use of patients within onemonth after the first laser therapy Patients were asked several questions related

to frequency of sunscreen use, time of applying sunscreen, components ofsunscreen preparations, types of sunscreen preparations, SPF of sunscreenpreparations, and side effects of sunscreen products

Besides knowledge, attitude and behavior, demographic characteristics ofpatients are also added in the study framework There are 12 variables those will

be investigated in this study They consist of gender, history of pregnancy, age,ethnicity, marital status, types of occupation, education, self-reported skin type,family history of melasma, daily sun exposed time, melasma recurrent historyand family income All of these demographic characteristics were included inthe framework as modifiable factors that could have an impact on knowledge,

Sunscreen behavior

Type of sunscreen products Time of applying sunscreen Side effects of sunscreen Frequency of sunscreen use Components of sunscreen SPF of sunscreen

attitude and behavior of sunscreen use

The study framework could be summarized in the following diagram

Firgure 3.1 The KAP and demographic framework in the present study

3.4 Sampling issues

3.4.1 Sample size

All patients with melasma who visited the Demartology Hospital forreexamination after one-month laser treatment between April and May 2015were enrolled in the study

3.4.2 Sampling creteria

Patients that were involved in health care professions or had a highereducation in medical sciences are excluded from the study Additionally,patients who could not take part or do not want to take part in interviews will beexcluded as well

3.4.3 Research instruments

A structured questionnaire is designed to measure the knowledge, attitudesand use of sunscreen behavior The questionnaire included 4 sections with 35question items The first section included 11 items that focused oncharacteristics of study subject such as sex, age, marital status, education,family income per month, indoor or outdoor occupation, self-reported skin type(whether or not skin burns after prolonged exposure to intense sunlight) and thedaily duration of exposure to sun

The second section of the survey included 7 questions about knowledge of

of sun exposure and sunscreen use The knowledge questions were in a multiplechoice format, with one correct answer for each question Knowledge isevaluated using the total scores for each subject on knowledge questions, withone point for each correct answer and zero points for each incorrect answer, to amaximum of 7 potential points if one answers all knowledge questionscorrectly

The third section of the questionnaire included 11 questions about attitude

of participants to sunscreen use The scale of measurement applied for attitudequestions is five-point Likert scale Each item was scored five points for themost positive (favorable to sunscreen) and one point for the most negative(against sunscreen) attitude Attitude toward sunscreen use was measured bysumming obtained scores on attitude items for each subject With a total of 11attitudinal question items, the possible total attitude score for each subjectranged from 11 to 55 These attitudinal question items were in three categories(economic, physical and emotional) ranging from totally agree to totallydisagree The economic aspect of attitude consisted of two items including:

"Using sunscreen is an extra cost"; and "Buying sunscreen is only beneficiaryfor cosmetic industries" The physical aspect of attitude consisted of two items