Psychosocial Factors Associated with Medical Treatments and Outcomes 109mortality, and urgent/emergent medical care. There are dif-
ferent methods to describe adherence: in terms of the overall
percentage of prescribed medication that is taken, or as a per-
centage of a sample that takes an adequate amount of med-
ication, with a criterion for adequacy de“ned as a proportion
of the total prescribed (e.g., 70%). Using the former method,
a recent review estimated that patients take about 50% of pre-
scribed medication (Bender, Milgrom, & Rand, 1997), but
single studies suggest that the problem with nonadherence
may be even more signi“cant. For example, one study
reported that 30% of their participants took 50% of more of
prescribed medications (F. Dekker, Dieleman, Kapstein, &
Mulder, 1993). Adherence with reliever medications is typi-
cally better than with controller medications (e.g., Kelloway,
Wyatt, DeMarco, & Adlis, 2000). There are a number of rea-
sons why patient use of reliever medications is more than
controller medications, such as the fast-acting effects of the
former being more reinforcing than the use of the latter, de-
spite the greater importance of controller medications in on-
going asthma management.
Researchers have cast a broad net in their efforts to under-
stand adherence dif“culties and identify predictors of nonad-
herence. There are methodological challenges inherent in the
study of adherence, ranging from the evidence that such re-
search is reactive (that participants change their medication-
taking behavior when they know it is monitored), that assays
for levels of common asthma medications in body ”uids
(serum, urine, saliva, etc.) do not exist, to ethical considera-
tions in the covert monitoring of medication use (with covert
monitoring methodology, deception may be involved in
which participants do not receive full disclosure regarding the
purposes of the research: see Levine, 1994). Recent efforts to
understand better the perspective of the patient through qual-
itative research (Adams, Pill, & Jones, 1997) and the devel-
opment of self-report measures to assess patients• reasons for
and against taking their asthma medications as prescribed
(Schmaling, Afari, & Blume, 2000) may lead to effective
patient-centered interventions to improve adherence. For ex-
ample, a pilot trial with patients with asthma comparing edu-
cation with education plus a single session of motivational
enhancement therapy (MET) (W. Miller & Rollnick, 1991),
a structured client-centered psychotherapy, found that MET
improved attitudes toward taking medications among patients
initially unwilling to or ambivalent about taking medications
as prescribed (Schmaling, Blume, & Afari, 2001).
Research on predictors of adherence has revealed that speci“c
sociodemographic variables are linked to adherence, includ-
ing age and gender. Older age (Bosley, Fosbury, & Cochrane,
1995; Laird, Chamberlain, & Spicer, 1994; Schmaling, Afari, &
Blume, 1998), female gender (Gray et al., 1996; Jones, Jones, &
Katz, 1987), more education (Apter, Reisine, Af”eck, Barrows,
& ZuWallack, 1998), Caucasian ethnicity (Apter et al., 1998),
and higher socioeconomic status (Apter et al., 1998) have been
associated with better adherence to medication regimens among
patients with asthma.
Adherence with medications is only one component of
treatment adherence. Research has yet to focus on other
components of treatment adherence, such as adherence with
allergen avoidance and environmental control. Indeed, a
prerequisite for patient adherence with such measures would
be receiving information and education on allergen avoid-
ance and environmental control from providers. Yet, despite
practice guidelines that mandate allergy evaluations, provider
adherence is low„among 6,703 patients with moderate or
severe asthma across the United States, less than two-thirds
of patients reported ever having had an allergy evaluation
(Meng, Leung, Berkbigler, Halbert, & Legorreta, 1999).
There may be a number of pragmatic barriers to the consis-
tent implementation of practice guidelines. For example,
with increasing pressure for treatment providers to see more
patients in less time, relatively time-consuming interventions
(such as education) may be curtailed or skipped. In a man-
aged care setting, referrals for allergy evaluations may be
avoided for “nancial reasons. Or, limited dissemination may
result in some treatment providers being unaware of current
practice guidelines. Patients who receive their asthma care
from a specialist rather than a general practitioner have self-
care practices more consistent with treatment guidelines
(Legoretta et al., 1998; Meng et al., 1999; Vollmer et al.,
1997). The extent to which practitioners• behavior is consis-
tent with practice guidelines should be determined before
assessing patients• behavior; patients should not be consid-
ered nonadherent if the appropriate evaluations and treat-
ments have not been “rst established by the practitioner.
However, these steps have not been taken consistently in the
studies to date. Investigations on factors associated with
atopic patients• adherence with allergen avoidance or control
(e.g., regular cleaning and washing to decrease dust mite
exposure) would be a useful area for future research.PSYCHOSOCIAL FACTORS ASSOCIATED WITH
MEDICAL TREATMENTS AND OUTCOMESPsychiatric DisordersPsychiatric disorders impede the ability of patients with
asthma to perceive accurately their pulmonary status, and
to respond appropriately. Both poor perceivers, whose per-
ceived breathlessness is less than actual air”ow limitation,