Handbook of Psychology

100 Asthma

psychosocial variables may be implicated in the initiation,
course (exacerbations versus quiescence) and outcomes
(morbidity, mortality) of asthma; psychological interven-
tions have a role in the treatment of asthma as a complement
to the use of medications.

EPIDEMIOLOGY AND HEALTH CARE COSTS
RELATED TO ASTHMA

Approximately 7.5% of the U.S. population reports having
asthma, or about 17 million persons (Centers for Disease Con-
trol, 2001). (The estimated lifetime rate for asthma is 10.5%.)
Approximately one third of persons with asthma are children
under the age of 18. Although most but not all asthma is iden-
ti“ed in childhood, asthma does not resolve in puberty or
adulthood for the majority of cases. Asthma has been reported
to be more common among women (9.1% versus 5.1% among
men), persons with less family income (9.8% among persons
with family incomes of less than $15,000 per year versus 3.9%
among those with more than $75,000 per year), and among
persons of African American ethnicity (8.5% versus 7.1% for
Whites and 5.6% for persons of other racial/ethnic back-
grounds) (Centers for Disease Control and Prevention, 2001).
The cause for gender differences in self-reported asthma is
unknown; greater body mass (Camargo, Weiss, Zhang,
Willett, & Speizer, 1999) and/or use of exogenous hormones
(Troisi, Speizer, Willett, Trichopoulos, & Rosner, 1995) may
contribute to higher rates of asthma among women.
Prevalence and mortality rates have been steadily in-
creasing in recent decades. According to the National
Health Interview Survey the age-speci“c prevalence rate for
self-reported asthma increased 58.6% between 1982 and

1996. In particular, the prevalence rate increased 123.4%
      during these 14 years (1982...1996)for young adults aged 18
      to 44 years (American Lung Association, 2001). The age-
      adjusted death rate for asthma increased 55% between 1979
      and 1998, totaling over 5,400 persons per year in 1998
      (American Lung Association, 2001), although such “gures
      based on reviews of death certi“cates may underestimate
      the actual mortality attributable to asthma (Hunt et al.,
      1993). Environmental factors such as pollution only par-
      tially explain the increase in asthma prevalence and mor-
      tality. Of interest is the psychosocial factors that may
      contribute directly or indirectly to the increasing prevalence
      and mortality related to asthma. Purely biological explana-
      tions are believed to be insuf“cient to explain asthma onset,
      exacerbation, or its rising prevalence, as a •paradigm shiftŽ
      (Wright et al., 1998). A conceptualization of asthma as hav-
      ing emotional and psychosocial components is not novel,

however. From the early twentieth century, asthma was con-

sidered a prototypical •psychosomaticŽ disease (Groddeck,

1928). Developments in psychoneuroimmunology may be

contributing to a new synthesis and appreciation for how bi-

ological and psychological systems interact to produce and

maintain asthma.

Asthma is costly. In 2000, U.S. asthma care totaled

$12.7 billion in direct and indirect costs, including costs

associated with premature death and time away from work

because of asthma (see http://www.lungusa.org/data/asthma/

ASTHMA1.pdf). In the United States, approximately 3 mil-

lion days of work and 10.1 million days of school are lost

each year due to asthma. Of particular interest to persons in-

terested in psychosocial factors associated with asthma might

be the costs associated with adherence and nonadherence to

self-care regimens (we address psychosocial factors associ-

ated with adherence in a later section). For example, persons

who are adherent with their medication regimens may incur

more direct costs in medications and scheduled outpatient

of“ce visits. By contrast, persons who are less adherent with

their medication regimens may incur less direct costs for

medications and outpatient of“ce visits, but incur more costly

occasional unscheduled visits, such as urgent care or emer-

gency room visits. While we are unaware of data that report

costs associated with groups of patients differentiated by

their behavior, psychiatric comorbidities, or other variables

of interest, the “nancial (and other) ef fects of optimal and

nonoptimal behavioral self-management is an issue worthy

of further exploration (and a potential source of information

that would motivate patients to be more adherent with their

medications).

EVIDENCE BASIS FOR PSYCHOLOGICAL

THEORIES APPLIED TO MECHANISMS

INVOLVED IN ASTHMA

Classical and Operant Conditioning

It would be possible for asthma to be a classically condi-

tioned response if allergens and irritants that caused bron-

choconstriction were repeatedly linked to a novel stimulus,

thereby creating a conditioned stimulus. There are case stud-

ies in the literature that describe conditioned visual stimuli

(E. Dekker & Groen, 1956) and other stimuli (the experi-

mental setting: a provocative inhaled substance given in the

experimental setting produced asthma, the substance was

omitted in subsequent experimental trials) (E. Dekker, Pelser,

& Groen, 1957) that provoke asthma attacks in participants

with asthma. Respiratory resistance has been classically