Validation of a Questionnaire for Assessing …

1 PEDIATRIC ASTHMA, ALLERGY & IMMUNOLOGYV olume 20, Number 4, 2007 Mary Ann Liebert, : of a Questionnaire for Assessing Adherence toMetered-Dose Inhaler Use in Asthmatic ChildrenCARLOS E. RODRIGUEZ MARTINEZ, , MSc.,1 MONICA PATRICIA SOSSA, , MSc., 2and CYNTHIA S. RAND, therapies for asthma are vulnerable to low adherence. Clinicians would bene-fit from having a validated Questionnaire to assess adherence to metered-dose inhaler use inchildren with asthma. The objective of this study was to design and validate a questionnaireassessing adherence to metered-dose inhaler use, to be filled out by the parents and/or care-givers of children with asthma. The six questions on the Pediatric Inhaler Adherence Ques-tionnaire were obtained from reviewing the literature, from carrying out focus group dis-cussions, and from the researchers professional experience.

2 We assessed concurrentcriterion validity using canister weight change as the gold standard and also assessedtest retest reliability. The Questionnaire was administered to the parents/caregivers of 64children aged years. Questionnaire scores correlated positively with the absolutevalue of the difference between 100 and percent taken of prescribed (Spearman correlationcoefficient rho , p ). The sensitivity of the Questionnaire in detecting nonad-herent patients ranged from 50% to 75%; positive predictive value ranged from ; and likelihood ratio ranged from to for the detection of nonadherent Pediatric Inhaler Adherence Questionnaire is a valid, reliable, quick, inexpensive, andeasy-to-use instrument that allows quantitative assessment of metered-dose inhaler adherencein children with asthma, and may be useful across a range of clinical and research settings.

3 (Pediatr Asthma Allergy Immunol 2007; 20[4]:243 253.)INTRODUCTIONTREATMENT ADHERENCEis generally defined as the degree to which a person s conduct with regard todrug therapy approaches the physician s treatment adherence is an everydayconcern in clinical practice, and has been widely reviewed in the literature, both for adults and to suggested asthma treatments varies from 15% to 67%.3 7 This depends on many issues,including their long duration, fears that inhalers might cause dependency or addiction, fear of the side ef-fects of inhaled steroids, disbelief in the need for daily treatment, cost of medication, the use of multiplemedications, administration schedules, and the symptom-free periods of the ,2,8 Low treatment ad-2431 Department of Pediatric Respiratory Medicine, Clinica Colsanitas, Clinica Infantil Colsubsidio, Bogota, of Internal Medicine, Clinica Colsanitas, Bogota, of Pulmonary and Critical Care Medicine, Johns Hopkins School of Medicine, Baltimore, can cause therapeutic failure, need to increase medication dosage or add other medications, needfor costly diagnostic testing, and unnecessary morbidity and even.

4 2 Self-report of asthma medication use by the patient (or by parents or caregivers in the case of children)is a widespread measurement of adherence used in both clinical and research is quick, inex-pensive, and easily available in everyday clinical ,9 Some asthma management questionnaires in-clude items related to asthma medication in children9 11but do not include assessment of adherence to thesemedications. To our knowledge, no validated Questionnaire has been reported in the literature that can as-sess adherence to metered-dose inhaler (MDI) use in children with asthma, as reported by parents or main objective of this study was to design and validate a Questionnaire Assessing adherence to MDIuse in young children with asthma, to be filled out by their parents or caregivers. A secondary objectivewas to determine the leading causes of low MDI adherence in young AND METHODSP atientsThis prospective cohort study was conducted at Cl nica Infantil Colsubsidio, a third-level, multidiscipli-nary teaching hospital located in Bogot , Colombia.

5 All children (and their parents/caregivers) under 8 yearswho were diagnosed with persistent asthma, prescribed daily treatment with an MDI, and whose first visitto our outpatient Pediatric Pulmonary Unit took place between November 2005 and March 2006 were in-cluded. Parents/caregivers of participating children were native Spanish speakers, with widely varied edu-cational background (at least 5 years of formal education) and socioeconomic status, but with an accept-able reading speed and ability. This unit usually conducts an individual educational intervention for theparents of all children with asthma, the purpose of which is to increase adherence to MDI use by educat-ing parents about asthma as a chronic inflammatory condition. Families were part of this educational in-tervention while doing the study. All patients were instructed to use a spacer with their MDI.

6 Patients whoused MDI without adult supervision and those who depended on more than one adult for their MDI ad-ministration were excluded. Study methods were approved by the Clinic s Ethics Committee, and childrenwere enrolled after informed consent was obtained from their development and scoringWe designed the Pediatric Inhaler Adherence Questionnaire (PIAQ) for this study based on a literaturereview,9 14answers and observations given by parents of children with asthma in four focus groups, andthe professional experience of the researchers. The same experienced facilitator conducted the four focus group session lasted 2 hours; all were tape-recorded and transcribed. The focus group facil-itator used a standardized script of open-ended questions. The questions posed to the parents in the focusgroups were What things have made it difficult to follow the physician s recommendations about the in-haler use for your asthmatic child?

7 And Of these things, which are most significant to you and your childwith asthma? Each comment by a parent was reviewed and grouped with other comments that had a sim-ilar subject matter. Two independent raters reviewed the transcripts and classified parents comments asbarriers or nonbarriers to and content validity were assessed by a multidisciplinary group with ample experience in the treat-ment of children with asthma two pediatric pulmonologists, one pediatrician, one physical therapist, andone clinical psychologist. Each member of the team was asked to evaluate the Questionnaire by assigningto each item a number from 0 to 2, 0 indicating the item had no importance and 2 indicating it had greatimportance and needed to be kept on the final instrument. Later, each item s average score was calculatedand items were ranked.

8 Those with the lowest scores were considered candidates for , the Questionnaire was piloted in four groups of parents of asthmatic children. Each group consistedof the parents of 10 to 15 asthmatic children; the population was a convenience sample enrolled sequen-RODRIGUEZ MARTINEZ ET in the same institution where the study was carried out. The pilot studies evaluated item comprehen-sion, ambiguous wording, floor and ceiling effects, the presence of questions with affective loading, andtime needed to complete the ,16 Items with responses in a certain direction more than 95%of the time were considered candidates for removal. Items were added, modified, or removed based on in-formation collected, until the final Questionnaire had the six items shown in Table the Questionnaire inquires about behaviors that could be considered undesirable and thus mightbe underreported ( , failure to use MDI according to medical recommendations), the Questionnaire s in-troduction encourages parents to report those behaviors or attitudes candidly17 (Table 1).

9 The Questionnaire inquires about possible missed and/or additional doses of controller MDI during thepreceding 15 days. The questions following those asking about missed/additional doses explore the possi-ble causes of these two types of low adherence. Since individual patients may use different controller MDIs,the Questionnaire leaves a blank space to provide the name of the prescribed medication. Because all thestudy participants were patients from the Plan Obligatorio de Salud (Compulsory Health Insurance Plan),which provided the medication, however, all patients used the same controller MDI (beclomethasone dipro-prionate).The Questionnaire s final two questions ask about any potential causes of apparently greater MDI use(MDI use by a person other than the patient or, MDI discharges in the air) (Table 1).Answers to questions 1 and 3 were scored from 1 to 5, with lower scores corresponding to greater ad-herence.

10 Item scores for these two questions were then added for a total score ranging from 2 to 10, withhigher scores indicating lesser adherence to MDI. In order to carry out statistical analysis, the answers toquestions 1, 3, 5, and 6 were not only collected as ordinal categorical variables, but also as continual vari-ables. The PIAQ was defined as positive for nonadherence to MDI use if a score of 3 or higher was ob-tained, and negative for nonadherence if a score of 2 was of the psychometric characteristics of the Questionnaire and study developmentIn order to assess the PIAQ s concurrent criterion validity, adherence to MDI use inferred from answersto the Questionnaire was compared with adherence determined by weighing inhaler canisters. In order tocalculate this adherence metric as our study s objective gold standard, inhaler canisters were weighed intriplicate on a digital electronic precision scale (Ohaus Portable Advanced Electronic Scale) ontwo different occasions separated by 15 days.