Treatment Adherence Among Low-Income Children With Asthma

Transcription

1 Journal ofpediatric Psychology, Vol. 23, No. 6, 1998, Treatment Adherence Among Low-Income Children With Asthma Marianne Celano, 1 PhD, Robert /. Geller, 1 MD, Keith M. Phillips, 1 MD, and Robin Ziman, 2 MPH 'Emory University School of Medicine and 2 Emory University School of Public Health Objective: To investigate the adherence behaviors (MDI use, MDI/spacer technique, appointment attendance, smoking in the home) of low-income, urban, primarily African American children with asthma. Method: Participants were 55 children ages 6 to 17 with moderate to severe asthma. Adherence to MDI anti-inflammatory agents was estimated primarily from canister weight at the follow-up appointment. Results: The mean use of MDI medication was 44% of prescribed use, with 27% of subjects demonstrating MDI/spacer technique likely to prevent drug delivery. Almost half reported that household members smoked cigarettes, and 21% missed scheduled follow-up appointments. Conclusions: These findings have implications for how clinicians should assess and improve adherence. Key words: adherence; asthma; children; metered-dose inhalers; low-income; socioeconomic status. African American children from low-income urban families are disproportionately afflicted by pediatric asthma and show higher rates of morbidity and mortality (Schwartz et al., 1990). Adherence may pose a significant challenge to these families due to their limited access to routine medical care and to the difficulty of limiting exposure to environmental triggers beyond parents' control (e.g., pollution, cockroaches). Despite the imperfect relationship between adherence and health outcome in asthma, children who do not take their asthma medications as prescribed are at increased risk for mortality from asthma (Strunk, Mrazek, Fuhrmann, & LaBrecque, 1985). Conceptualized as a multidimensional construct (La Greca & Schuman, 1995), adherence refers to a domain of discrete behaviors corresponding to multiple components of treatment. The current treat- This study was supported by a grant from the Emory Medical Care Foundation. Portions of this article were presented at the Fifth Florida Conference on Child Health Psychology. All correspondence should be sent to Marianne Celano, Department of Psychiatry, Box 26064, Grady Health System, Atlanta, Georgia mcelano@emory.edu. ment approach for asthma includes two broad components: medication and avoidance of substances known to trigger exacerbations. In general, anti-inflammatory agents are prescribed to be used daily for prophylaxis, whereas bronchodilators (e.g., albuterol) are prescribed for use before exercise and as needed for symptom relief. Estimates of adherence to asthma medications vary widely, depending on medication, method of assessment, research setting, population, and asthma severity (Lemanek, 1990). Although bronchodilator and anti-inflammatory agents delivered by metered dose inhaler (MDI) are the most commonly prescribed medications for school-age children with moderate to severe asthma, relatively few studies have examined children's adherence to these agents. Further, there is no "gold standard" for measuring adherence in pediatric asthma; the varying severity and the intermittent nature of the disease have impeded reliable assessment (Lemanek, 1990). Several investigators have attempted to assess 1998 Society of Pediatric Psychology

2 346 Celano, Geller, Phillips, and Ziman MDI use by weighing canisters. Zora, Lutz, and Tinkelman (1989) used canister weights to estimate the adherence of a sample of 17 children over 2 to 4 weeks. Three (18%) of the children used their MDI as directed; most of the remaining children used their MDI less frequently than prescribed. Furthermore, only one child's diary of medication use matched within 10% MDI use as determined by canister weight. Using a different formula for determining adherence from canister weight, Smith, Seale, and Shaw (1984) found poor adherence to MDI agents among a sample of children followed over 2 to 6 weeks. For example, 28% of 74 children using beclomethasone attained 50% adherence or less as determined by canister weight. However, there was no significant difference between the children's selfreported adherence to MDIs and their estimated adherence. Although canister weight may provide a more valid estimate of actual MDI use than patient's or parents' self-report, it has been argued that multiple methods of assessment are needed, particularly when the demand characteristics of the study setting emphasize adherence (Rand & Wise, 1994). In the present study, both canister weight and selfreport (children's and parents') were used to estimate MDI adherence. The canister weight method was chosen over the Nebulizer Cronolog device (which stores the date and time of each actuation; Spector, 1985) to minimize demand characteristics as well as expenses. That is, canisters can be weighed periodically without patients' knowledge, whereas the Nebulizer Cronolog is attached to the MDI while the patient uses it. The main purpose of the study was to determine the levels, distributions, and interrelationships of four adherence behaviors: (1) use of an anti-inflammatory agent between two consecutive appointments, (2) the child's observed technique using an MDI with a spacer device, (3) attendance at routine appointments for follow-up of asthma treatment, and (4) absence of cigarette smoke in the home. Method Procedure Participants were recruited from the pediatric asthma/allergy clinic at a large urban hospital. Eligible participants were those 6 to 17 years of age with moderate to severe asthma according to established criteria (U.S. Department of Health and Human Services, 1992). Participants were excluded if they were currently receiving immunotherapy because this treatment required weekly appointments. Participants also were excluded if they were prescribed oral steroids for a significant period (i.e., more than a total of four weeks in the past year, or longer than two weeks on a daily basis) due to the potentially confounding effect of oral steroids on measures of psychological adjustment used for another study at this site. Parents of eligible children were invited by a research assistant to participate in a study of pediatric asthma and told of the incentive ($5 food certificate) for bringing their child's asthma medications to the next appointment. Parents gave informed consent and children (over 12 years) gave written or verbal assent. The parent and child were then each interviewed separately by a research assistant or psychologist not involved in the clinical care of the child. The next asthma clinic visit was scheduled at their convenience, usually 4 to 12 weeks later, depending on the child's medical needs. Parent and child were again interviewed separately, and the child's canisters were weighed without his or her or the parent's knowledge. Participants Sixty-one children and their parents were successfully recruited to participate in the study. Four eligible families refused participation, and 6 families never returned for a follow-up appointment, leaving a sample of 55 families. Most of these children (98%) were African American; 57% were males. They ranged in age from 6 to 17 years (M = 10.8, SD = 2.7), had been diagnosed with asthma for a mean of 7.3 years (range = 1 to 13), and were currently prescribed a mean of 2.6 asthma medications (range = 1 to 7). All children were prescribed an albuterol MDI and at least one anti-inflammatory agent delivered by MDI and a spacer. The interval between study entry and follow-up ranged from 2 to 20 weeks, with a mean of 10 weeks. Although the follow-up appointment was usually scheduled for 4 to 12 weeks later, several families missed one or more follow-up appointments and were rescheduled for a later time. Participating caregivers were mothers (91%) ranging in age from 25 to 63, with a mean of 37 (SD = 7.9). Most caregivers (79%) were either single,

3 Treatment Adherence Among Children With Asthma 347 separated or divorced, and 28% shared parenting of the target child with a caregiver in a separate household. Over three quarters (77%) had completed high school, and 75% were receiving Medicaid, AFDC, and/or SSI. Hollingshead Four Factor scores ranged from 11 to 48, with a mean of 25 (SD = 8.4), corresponding to the social strata occupied by semiskilled workers. Measures Estimated MDI Adherence. Estimated adherence was operationalized as the ratio of the number of puffs used over the study period to the number of puffs prescribed. The number of puffs utilized by the patient was estimated from two criteria: the weight of the canister(s) brought in to the follow-up visit, and the child's report of how many canisters he or she completed, supported by pharmacy records. The latter criterion was needed because many children were prescribed more than one canister over the study period, and few brought in empty canisters. Canisters were weighed on an Ohaus CT200 digital scale with stated linearity to.01 grams. Prior to use, the scale was calibrated using.01 and 200 gram weights calibrated to National Bureau of Standards (NBS) weight standards. To calculate the number of puffs used from canister weight, we weighed six "test" canisters from two to three lots of each agent at intervals of 10% of the labeled number of puffs in each canister (e.g., 240 for Azmacort). These data yielded a graph of the mean amount used for each agent by canister weight, which we used to determine the number of puffs corresponding to the weight of a partially used canister. If the canister was reported to be completely used (empty), we used the mean number of puffs in the six "test" canisters (e.g., 263 puffs for Azmacort), as the actual number of puffs per canister varied and always exceeded the labeled amount. For example, a child prescribed Azmacort 4 puffs BID for 70 days (560 puffs) brings one canister weighing grams, corresponding to 27% use (65 puffs), and reports that she finished one more canister (263 puffs), supported by pharmacy records. Her estimated use is 328 puffs; her estimated adherence is calculated as 328/560, or 59%. Self-Reported Adherence. Children and parents were individually asked how many days per week (on average) they had used each agent. All children who reported missing their MDI medication on at least one day were also asked why they missed their medication. They were shown a poster with eight illustrations and matching titles (forgot to bring it with me, forgot to take it, don't know how to use it, don't like the taste, medicine doesn't help my asthma, don't need it every day, embarrassed to take it, ran out of medicine) and asked to select those corresponding to their reason for missing the medication. Metered-Dose Inhaler Checklist (MDIC). This observational rating scale was developed by Boccuti and colleagues (Boccuti, Celano, Geller, & Phillips, 1996) to measure children's technique in using their MDI with a spacer. The MDIC has acceptable internal consistency reliability. The dichotomous scoring system (Boccuti et al., 1996) was used to facilitate comparisons among the three spacers utilized in this study. The MDIC was completed at the follow-up appointment by the nurse or physician involved in the child's care; all five practitioners had previously been trained until they achieved 100% agreement on all MDIC items. Results Of the 55 children seen at follow-up, two were dropped from all analyses because of contradictory or unavailable information in the medical chart about the prescribed treatment regimen. Adherence Variables Estimated MDI Adherence. Only 34 subjects had complete data to evaluate their MDI adherence. Despite incentives and telephone reminders, 12 subjects did not bring canisters to the follow-up visit; an additional 7 did not report sufficient information about their MDI use to estimate adherence. Twenty-seven (79%) brought Azmacort, three (9%) brought a beclomethasone MDI agent, three brought Intal, and one brought Tilade. Estimated MDI adherence for the 34 subjects with canister weight data ranged from 0% to 100%, with a mean of 44%. The distribution of estimated adherence was skewed, with a mode of 0% (four cases) and only 12% with adherence rates higher than 75%. The correlations between estimated adherence and parent reports of adherence were nonsignificant and minimal. In contrast, estimated adherence was found to be positively but not significantly correlated with the child's report of the number of days per week that he or she used the MDI (r =.31,

4 348 Celano, Geller, Phillips, and Ziman Table I. Correlations Among Adherence Behaviors Reasons Given for not Taking Medications 1. Smoking in the home 2. MDIC score 3. Missed appointments 4. MDI use estimated from canister weight 5. Child's reported MDI use: days per week (1) (2).12 *p <.05, one-tailed planned comparison. **p <.01, one-tailed planned comparison. (3) (4) * (5) ".31* "Forgetting" was the top reason given for failing to take Azmacort and albuterol, endorsed by more than half of the sample. For Azmacort, the next most frequently given reasons were "don't like the taste" (21%) and "forgot to bring it with me" (16%). None of the other five reasons were endorsed by more than 10% of the sample. Despite the fact that over a quarter of the children obtained MDIC scores of zero, none stated that they failed to take their medication because they didn't know how to use it. n = 33). A r test between the more adherent (estimated adherence greater or equal to 50%) and less adherent (estimated adherence less than 50%) groups yielded a significant difference, r(31) = -1.67, p <.05, with the more adherent children reporting MDI use a greater number of days per week. MDI/Spacer Technique. The 53 study subjects had been taught proper MDI/spacer use, and their technique had been rated and corrected at study entry. At follow-up, 25 subjects (47%) were using the Azmacort spacer, 12 (23%) were using Optihaler, and 13 (25%) were using Inspirease. MDIC data is available for 49 of the subjects seen at follow-up. Thirteen subjects (27%) obtained a score of zero, indicating technique so poor as to minimize the likelihood of any delivery of the agent to the lung. The remaining 73% of the subjects demonstrated varying technique, but achieved minimum criteria to assure at least some drug delivery. Smoking; Missed Appointments. Almost half of the caregivers (48%) reported that household members smoke cigarettes. Forty percent indicated that they allow visitors to smoke in the home. Forty-two (79%) did not miss any scheduled follow-up appointments during the study period, and 11 (21%) did not show for one or more follow-up appointments. Correlations among Adherence Behaviors Table I shows the correlations among the five measured adherence behaviors. Children with poor adherence as estimated from canister weight were more likely to miss one or more appointments (r =.28, n = 34, p =.05). Similarly, children who reported poor medication adherence were more likely to miss appointments (r =.35, n = 50, p <.01). However, there was no significant relationship between the MDI adherence variables and the MDIC score or smoking in the home. Discussion Adherence to multiple components of asthma treatment was poor for our sample of urban, lowincome, primarily African American children with moderate to severe asthma. Almost half of the total sample reported that household members smoke cigarettes, and 21% missed one or more follow-up appointments made at their convenience. Despite instruction on how to use their medications, more than a quarter of the children demonstrated MDI/ spacer technique so poor as to make drug delivery to the lower airway improbable. For the 34 subjects who brought canisters to the follow-up appointment, the average use of anti-inflammatory MDI agents was estimated to be only 44% of prescribed use. These data suggest that adherence to asthma treatment among urban, low-income children may be even lower than the compliance rates reported previously (e.g., Smith et al., 1984; Zora et al., 1989), putting these children at increased risk for morbidity and mortality. Although the validity of the children's selfreported adherence is supported by the canister weight-based estimates, the correspondence between the two sources of information is far from perfect, and may not be clinically meaningful. For example, 14 children reported using their MDI every day at the dose they believe was prescribed, but only one child had 100% adherence and one child had 97% adherence according to canister weight data. These data suggest that children may overestimate their MDI adherence, even when reporting in confidence to a researcher. Nevertheless, health care providers may obtain a more accurate measure of a child's adherence if they question the child independently of his or her parents. Periodic weighing of canisters can be used to monitor the validity of self-reported adherence.

5 Treatment Adherence Among Children With Asthma 349 The correlational analyses showed that most of the measured adherence behaviors were not significantly interrelated. This is not surprising given that the various adherence tasks make different kinds of demands on different family members; for example, it is primarily the parents' responsibility to prohibit cigarette smoke and to keep appointments, and the child's responsibility to take medication as prescribed. The data suggest that children's accuracy in using their MDI/spacer should be assessed directly rather than inferred from information about the child's medication adherence. Because the MDIC identifies specific, sequential steps in MDI/spacer technique, it could be used by physicians and nurses to monitor the accuracy and consistency of children's MDI/spacer technique across health care settings (e.g., inpatient unit and outpatient clinic), and by parents to supervise their children's MDI/spacer use at home (Boccuti et al., 1996). Efforts to improve children's MDI adherence should be based on a thorough understanding of the developmental and family context of children's self-care. For example, children may have "forgotten" to take their medication because a parent neglected to supervise medication administration. Asked in individual follow-up interviews what parents could do to get their children to take their asthma medications, most children and parents said that parents should "watch" their child use his or her MDI and spacer. Adherence improvement strategies might include education about how parents can better supervise medication administration and/or how they can help their children to take more responsibility for asthma management. Given that over a quarter of the caregivers in our sample shared parenting with an adult in a separate household, interventions to improve adherence should include the direct participation of all of the child's caregivers. The current study is limited by the methodology used to assess MDI adherence, the relatively small sample size, and the variable interval over which adherence was measured. These limitations are related in part to the poor adherence in our clinic setting; for example, many patients did not return for a.follow-up visit or bring required medicines. Although pharmacy records were used to document that parents obtained medicines, there is no proof that the children used unweighed inhalers as prescribed. Similarly, although all the children denied using "old" (previously prescribed) inhalers or inhalers prescribed to others, there is no guarantee that they were not trying to use unauthorized medications. Future research should include low-income samples across sites to improve the generalizability of findings. Given the risks posed by poor adherence among urban, low-income children with asthma, greater and coordinated efforts should be made to improve their adherence to multiple components of their treatment regimens. Received April 10, 1997; accepted April 18, 1998 References Boccuti, L., Celano, M., Geller, J. R., & Phillips, K. M. (1996). Development of a scale to measure children's metered-dose inhaler and spacer technique. Annals of Allergy, Asthma, & Immunology, 77, La Gteca, A. M., & Schuman, W. B. (1995). Adherence to prescribed medical regimens. In M. Roberts (Ed.), Handbook ofpediatric psychology (2nd ed., pp ). New York: Guilford. Lemanek, K. (1990). Adherence issues in the medical management of asthma. Journal ofpediatric Psychology, IS, 437^57. Rand, C. S., & Wise, R A. (1994). Measuring adherence to asthma medication regimens. American Journal of Respiratory Critical Care Medicine, 149, Schwartz, J., Gold, D., Dockery, D. W., Weiss, S. T., & Speizer, F. E. (1990). Predictors of asthma and persistent wheeze in a national sample of children in the United States. American Review of Respiratory Diseases, 142, Smith, N. A., Seale, J. P., & Shaw, J. (1984). Medication compliance in children with asthma. Australian Paediatric Journal, 20, Spector, S. L. (1985). Is your asthmatic patient really complying? Annals of Allergy, 55, Strunk, R. C, Mrazek, D. A., Fuhrmann, G. S. W., & La- Brecque, J. F. (1985). Deaths from asthma in childhood. Can they be predicted? Journal of the American Medical Association, 2S4, U.S. Department of Health and Human Services, Public Health Service, National Institutes of Health. (1992). International Consensus Report on Diagnosis and Management of Asthma (Pub. No ). Zora, J. A., Lutz, C. N., & Tinkelman, D. G. (1989). Assessment of compliance in children using inhaled beta adrenergic agonists. Annals of Allergy, 62,