Japanese
Journalof Community
Pharmacy
Vol.5,toNo.2,28-37 (2017)
Inadaet al.；Factors
influencing
adherence
medication《 Original Article 》

Factors influencing adherence to medication based on questionnaire survey
Manabu Inada , Kazumi Ishitsuka2, Mariko Ueda , Masayoshi Koinuma ,Hitomi Kashiwase2, Masanori Shimada , Yuko Matsuzaki , Kazuhiro Torigoe2,
Shotaro Sakurai2, Tetsuro Yumoto2 and Hajime Ito
Over the past few years, home medical care and chemotherapy on an outpatient basis have beenpromoted, and pharmacists at community pharmacies are being asked to strictly manage patientadherence to their medication. The current study e amined factors that influence adherence tomedication as a potential source of information for use in clinical settings.
Patients visiting community pharmacies were surveyed and their responses were analyzed.
esponses were simply tallied and univariate analysis was performed to e amine factors related tothe attitudes of patients who failed to take their medication. Several significant variables wereidentified, so multiple logistic regression analysis of these significant variables was performed.
Of the respondents,.

answered that they failed to take their medication at least once a month.

esults revealed that dining out, having a job, and the number of medication types one was taking
led to decreased adherence to medication.

esults suggested that pharmacists need to routinely

collect information regarding these factors through interviews or an initial patient questionnaire.
Key words community pharmacies, adherence to medication, questionnaire survey,
multiple logistic regression analysis, dining out
eceived ugust 5, 2

1

ccepted November 25, 2administered during hospitalization to medication

Introduction

administered on an outpatient basis.

ccording toa rough estimate, the cost of medication left by

Over the past few years, home medical care has
thatpatients who forget to take it or who fail to take all

involving oral anticancer drugs is increasinglyof that medication amounts to about 5 billion yen

being administered on an outpatient basis.

per year .

e pandedandchemotherapy

includings aresult, drug therapy has shifted from medication

In order to organize medications andreduce medical e penses, the medical fee that

Innovation of Medical Service, Inc.,2Pharmaceutical education research center, Hoshi University,
epartment of Pharmaceutical Science, Teikyo Heisei University
Corresponding author Tetsuro Yumoto, 2bara, Shinagawa, Tokyo 2 5 , Japan
Phone
5Fa
55
mail t yumoto hoshi.ac.jp

28
28

2 28
Inada et al.；Factors inﬂuencing adherence to medication

22 e plicitly states that patients befailing to take one s medication. Moreover, thisasked about remaining medications as part ofstudy e amined issues with conventional interviews

management of medication history and providingand initial patient questionnaires.

was revised in 2

instructions

ontakingmedication.

Thisstipulation reaffirms the pharmacist s e pert role inaterials andethods

ensuring adherence to medication.
Community pharmacies collect information. Subjects and methods

from customers through interviews or, if this is theata from a survey were used. The survey wascustomer s first visit, an initial patient questionnaire.

conducted atHowever, there is no prescribed form for the initial

Health Insurance throughout Kanagawa Prefecture.

patient questionnaire, and a report have noted thatIn principle, the survey is conducted every months

medication history is not adequately assessed in

to gauge patient satisfaction and to improve thelight of requirements that must be met when

ability

pharmacists charge a fee for management of

instructions on taking medication.

medication history and providing instructions on

2 , 2ssociation has published a sample initial patientquestionnaire .

personneltoprovide. The survey took

hour and wasconducted during non peak hours so as to avoid
interrupting outpatient services. New patientsmong the questions regarding

meals, the sample form only asks

pharmacy

The survey was conducted from February 2 totaking medication. Thus, the Japan Pharmaceutical
2ofpharmacies that take National

would need too you takefill out an initial patientand specific foods e.g. grapefruitquestionnaire given the imposition that the survey

juice, natto, alcohol, and coffee . nd it does not ask

would place on them, new patients were e cluded.

about meal frequency or dining out.

Only returning patients served as potential subjects.

meals regularly

Potential subjects were asked to participate in thisPrevious studies on adherence to medication
have cited several factors that decrease adherence,

study

including adverse reactions, frequent doses, andquestionnaire, which they completed while waiting

taking numerous medications

to have their prescription filled. To ensure.

Moreover,those who consented were given thestudies have also revealed that conditions at work

completelyand meal consumption

questionnaire was anonymous.

or lack thereof

also

voluntarycooperation,

influence adherence to medication .
The aim of this study was conducted to e amine

2. Items studied

the hypothesis that the dietary habits or working

The items studied are shown in Table .

conditions of patients are related to adherence tomedication and to investigate the factors that
influence adherence to medication, i.e. reasons for

229

theJapanese
Journalof Community
Pharmacy
Vol.5,toNo.2,
28-37 (2017)
Inadaet al.；Factors
influencing
adherence
medication

30

2 28
Inada et al.；Factors inﬂuencing adherence to medication.

2

serving as e planatory variables. The significanceamining factors related to the attitudes oflevel was less than . 5.

patients who failed to take their medication

JMP

In order to e amine factors related to the attitudesof patients who failed to take their medication,.2

S SInstitutewasusedto

statistically analyze data in this study.

patients were classified depending on the frequency
or infrequency of adherence to their medication.

. Identifying factors related to the attitudes ofPatients whoproperly took their medication,

patients who failed to take their medication

those who failed to take their medication once aConfounding factors were e cluded.

year,

henand those whofailed to take theirunivariate analysis identified several significant

medication once every 2months were classified

variables, procedures were followed to identify

patients who adhered to their medication.

trends common to patients who often failed to take

Patients who frequently failed to take their

their medication. Multiple logistic regression

medication including those who failed to take theiranalysis using a stepwise procedure

medication

selectionas

2 times a month

were classified as

selection

criterion

pforward.25

waspatients who failed to adhere to their medication.

performed with significant variables serving as

This classification was based on the calculation thate planatory variables.

showed that achieving adherence to medication
5or higherJMP

in patients taking anti HIV.2

S SInstitutewasusedtostatistically analyze data in this study.

agents , which typically require a high level of
5. Privacy considerations

adherence to medication. t the lowest daily dosageof once a day, a patient is allowed to forget to takeIn order to safeguard the personal information of

his or her medication once a month. Patients wererespondents to this survey, the questionnaire wasscored fromanonymous. Moreover, a confidentiality agreement

points based onage groupss,

was concluded when information was disclosed toor older . The frequency distribution of

joint research institutions. Subjects were informed

scores was tested for normality. If it was not normal,

in writing that they could not be individuallythen scores were converted into binary data, i.e.

identified from their responses and that theirscores above and below the median score, and those

responses would not be disclosed to their primarydata were analyzed. The number of times one dined

physician.

under the age of 2 , 2 s,
and ages,s, 5 s,s,out per week was analyzed as the presence orabsence of dining out.

ata were statisticallyesultsprocessed in accordance with the following
procedures.

. Tallying of responses

Univariate analysis was performed with theThree hundred and eighty four questionnaires

attitudes of patients who often failed to take theirwere distributed andmedication serving as a response variable andresponse rate of

respondent characteristics and other responses

shown in Table , Fig.

31

were returned, for a. Tallies of questionnaires areand Fig. 2.

espondents

Japanese
Journalof Community
Pharmacy
Vol.5,toNo.2,28-37 (2017)
Inadaet al.；Factors
influencing
adherence
medicationconsisted of an almost even number of males andfemales. The median score for the age group waspoints

s , so the frequency distribution was notnormal.

espondents who were working almost

equaled those who were not working. espondents
were taking a median ofminimum
five tomedication types

types, ma imum 2 types . Twenty
5of respondents were taking 2 5

medication types, and the mode was 2 medication
types. Kurtosis was 5.

so it e ceeded

andskewness was . . Outliers were present at higher
values, and the distribution may have been biased.
Of thetotal respondents,.

25

respondents were patients who adhered to theirmedication.

The

most

frequent

reasonor

circumstance for failing to take one s medication
was forgetting to take medications inadvertently
2 .

,respondents , followed by forgetting

to bring medications.

,

respondents , andputting off taking medications.

,2respondents .
hen asked about how well they understood thedosing and dose of the medication they were taking,the vast majority of respondents
respondents

answeredmemorized

while 2 .

thatthey.

esults of e amining factors related to the,have

attitudes of patients who failed to take theiritmedication are shown in Table 2 and Fig.

respondents

Significant differences in responses toanswered that they refer to drug envelope . Thirty

nominalseven percent of respondents

presence or absence of working p

2 respondents

scalesage

groupwere taking medication three times a day while

medication before bed p

2 .

or absence of dining out p

respondents were taking medication.

p

items with.

.

.

5,the2 , taking, and the presence.

5

were noted

once a day . The timing of medication was mostTable

often in the morning , and medication was mostmedication types on a continuous scale yielded aoften taken after meals .

regression equation as shown in Fig.

2.

esponses regarding numberof. The

regression coefficient was negative, so patients
2.

amining factors related to the attitudes oftaking numerous medication types were less likely

patients who failed to take their medication

to fail to take their medication. Testing of the model
overall resulted in p
232.

, so the regression

2 28
Inada et al.；Factors inﬂuencing adherence to medication

2equation was significant.

individuals who realized that they had failed to takeIn other words, univariate analysis revealed that

their medication tended to be younger, they tended

233

Japanese
Journalof Community
Pharmacy
Vol.5,toNo.2,28-37 (2017)
Inadaet al.；Factors
influencingadherence
medication

to work, they tended to take fewer number ofnegative slope had on results was determined. In

medication types, they tended to take that

addition, the values represented the degree ofmedication before bed, and they tended to dining

influence. stimates for dining out more than onceout at least once a week.

weekly and working were positive, so individuals
who dining out at least once a week, individuals
who worked, failed to take their medication. In. Identifying factors related to the attitudes ofpatients who failed to take their medication

contrast, the estimate for the number of medication

Univariate analysis identified 5 significant

types was negative, so individuals taking fewer

variables age group, the presence or absence of

number of medication types failed to take theirworking, number of medication types, taking

medication.

medication before bed, and the presence or absence

Odds ratios revealed that individuals who diningof dining out . In order to identify factors

out at least once a week were about 2.2 times odds

related to the attitudes of patients who failed to takeratio 2.

their medication, multiple logistic regression

more likely to fail to take their medication than wereanalysis using a stepwise procedure was performed

individuals who did not dining out. Individuals whowith those 5 variables as e planatory variables, andworked were about 2. times odds ratio

results are shown in Table . Significant differences

confidence intervalin the presence or absence of dining out result of a

to take their medication.

chi squared test
p.

.

. ,p.

.2.2.

. 2

. , 5

more likely to fail, andnumber of medication types result of a chi squared.

confidence interval

iscussion, the presence or absence of working. ,p5,

result of a chi squared test
test,

dherence to medication has previously been

were noted. The slope of theassessed through methods such as measurement ofregression equation for estimates was determineddrug concentration in the blood or urine, directly

and the direction of the influence that a positive orobserving patients take medication, self reports,

34

2 28
Inada et al.；Factors inﬂuencing adherence to medication

factors were the presence or absence dining out, thesurveys of family members, and counting the, 2.

2

The current

presence or absence of working, and number ofstudy assessed adherence to medication based on

medication types. Completely forgetting to takecertain attitudes of patients who failed to take their

one s medication ,forgetting to bring one s

medicationa

medication , andputting off taking one sofmedication were leading reasons or circumstances

patients failed to adhere to their medication , while

for failing to take one s medication. Individuals did

most patients adhered to their medication. That said,

not take their medication at a time that suited them.

some respondents might have limited awareness oforking, being busy, and forgetting to bring

the need to take their medication despite failing to

one s medication can readily decrease adherence totake their medication.

small proportion ofmedication. Making a habit of taking one srespondents answered that they failed to adhere tomedication is crucial, regardless of e ternal reasons

their medication since may answered that theyor circumstances. To that end, pharmacists need toproperly took their medication.

be involved. The presence or absence regular meals

amount of remaining medication

basedonself reports

usingquestionnaire. esults indicated that about

wasesults of univariate analysis indicated that

believed, 5toinfluenceadherence

toindividuals who realized that they had failed to takemedication

their medication tended to be younger, they tended

the presence or absence dining out influences

to be working, they tended to take fewer number ofadherence to medication. The presence or absence

medication types, they tended to take medication

regular meals and the presence or absence dining

before bed, and they tended to dining out at leastout are items that need to be determined.

once a week.

, but the current study revealed thatased on the aforementioned findings, questions

Patients tend to be prescribed more medications

about dining out need to be included in initial visit

as they grow older , so adherence presumably

questionnaires and interviews, and information

becomes a habit.

Nationalneeds to be routinely collected from patients.

penditures by thePatients may be taking prophylactic medication for

Statistics ureau of the Ministry of Internal ffairs

a chronic condition such as hypertension, diabetes

and Communications revealed that the proportion of

mellitus, or a lipid abnormality even though theye penditures on dining out tended to decrease as

have no subjective symptoms . The disappearance

families grew older .

large proportion ofof symptoms or improved laboratory results canyounger age individuals work, they allocate little

lead to decreased adherence to medication. Intime for household chores, they become hungry

addition, involvement in treatment , awareness ofwhen they finish work, and they dine out for social

one s condition, and one s attitudes towards

reasons. Such factors presumably lead to decreased

treatment

adherence to medication.

patient s view on the significance of his or her

esults of the 2

Survey of Family Income andinfluence adherence to medication, so a

Multiple logistic regression analysis of theadherence to medication needs to be ascertained,

aforementioned factors was performed using aand adherence to medication needs to be e plained

stepwise procedure. esults revealed that principal

to the patient. Forgetting to take medication while35

Japanese
Journalof Community
Pharmacy
Vol.5,toNo.2,28-37 (2017)
Inadaet al.；Factors
influencing
adherence
medication

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5need to take an increased dose or take additional

Ikuo Saito, Medication compliance and blood

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Hiroko Tani, Hirokazu Misawa, Masumi Suyama,

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