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Original Research: CYSTIC FIBROSIS |

Impact of Socioeconomic Status, Race, and Ethnicity on Quality of Life in Patients With Cystic Fibrosis in the United States FREE TO VIEW

Alexandra L. Quittner, PhD; Michael S. Schechter, MD, MPH, FCCP; Lawrence Rasouliyan, MPH; Tmirah Haselkorn, PhD; David J. Pasta, MS; Jeffrey S. Wagener, MD
Author and Funding Information

From the Department of Psychology and Pediatrics (Dr Quittner), University of Miami, Coral Gables, FL; the Department of Pediatrics (Dr Schechter), Emory University School of Medicine, Children’s Healthcare of Atlanta, Atlanta, GA; ICON Clinical Research (Messrs Rasouliyan and Pasta), San Francisco, CA; EpiMetrix, Inc (Dr Haselkorn), Sunnyvale, CA; and the Department of Pediatrics (Dr Wagener), University of Colorado School of Medicine, Aurora, CO.

Correspondence to: Alexandra L. Quittner, PhD, University of Miami, Department of Psychology, PO Box 248185, Coral Gables, FL 33124-0751; e-mail: aquittner@miami.edu


Reproduction of this article is prohibited without written permission from the American College of Chest Physicians (www.chestpubs.org/site/misc/reprints.xhtml).


© 2010 American College of Chest Physicians


Chest. 2010;137(3):642-650. doi:10.1378/chest.09-0345
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Published online

Background:  Patient-reported outcomes are increasingly used in clinical trials to assess the natural history of chronic diseases and the efficacy of new treatments. Understanding the effects of socioeconomic and minority status on health-related quality of life (HRQOL) will facilitate interpretation of the results of clinical trials and suggest targets for interventions to improve patient care and outcomes. The objective of this study was to examine the effects of socioeconomic and minority status on HRQOL in patients with cystic fibrosis (CF) from childhood through adulthood in a large, comprehensive database containing medical and HRQOL data for patients with CF.

Methods:  A cross-sectional study was performed using data obtained from the Epidemiologic Study of Cystic Fibrosis on 4,751 patients and 1,826 parents who were non-Hispanic white, African-American, or Hispanic and who completed the Cystic Fibrosis Questionnaire-Revised (CFQ-R), a disease-specific HRQOL measure, during a stable clinic visit.

Results:  Multivariate models assessed the main effects of socioeconomic and minority status on clinical and HRQOL outcomes. Regression models that controlled for disease severity identified the contributions of these two variables to HRQOL. Low socioeconomic status was associated with significantly lower CFQ-R scores for children, parents, and adults on the majority of domains. After controlling for disease severity and socioeconomic status, African-American and Hispanic patients reported worse emotional and social functioning.

Conclusions:  Low socioeconomic and minority status may affect important clinical and patient-reported outcomes for patients with CF across their life span.

Figures in this Article

Patients with cystic fibrosis (CF) exhibit significant variability in the clinical course of their disease. Both minority status (race and ethnicity) and socioeconomic status (SES) contribute to this variability, possibly because of increased family stress, exposure to environmental toxins (eg, pollution, tobacco smoke), differences in disease self-management, and cultural perceptions of chronic illness.1-3 Hamosh et al1 controlled for genotype, but not SES, when they reported that African-American patients with CF had worse nutritional outcomes than non-Hispanic white patients. A CF Foundation National Patient Registry analysis using Medicaid status to control for SES found a marginal decrease in pulmonary function, but no difference in mortality, in African-Americans compared with whites.4 A second analysis using median family income by zip code as a marker for SES found that nonwhites and Hispanics had an increased mortality rate compared with white Americans5

Although health outcomes research has typically focused on biologic end points, greater attention is now being paid to patient-reported outcomes, such as health-related quality of life (HRQOL).6-10 We used data from the Epidemiologic Study of CF (ESCF),11 which contains both medical information and a disease-specific HRQOL measure, to examine the relationship between HRQOL and SES, race, and ethnicity. Four hypotheses were tested: (1) patients with low SES have worse health outcomes than patients with higher SES; (2) patients from ethnic and racial minorities have worse health outcomes than non-Hispanic white patients; (3) respondents from low SES backgrounds and racial and ethnic minorities report lower HRQOL scores than higher SES and nonminority respondents; and (4) in a multivariate analysis controlling for disease severity, low SES and minority status are associated with lower HRQOL scores.

ESCF is a multicenter, longitudinal, encounter-based study of CF care practices and outcomes in the United States.11 SES and HRQOL data, using the Cystic Fibrosis Questionnaire-Revised (CFQ-R), were added in 2003.12,13 The study was approved by local institutional review boards, and participants or their guardians provided informed consent.

Patients were included in the analysis the first time they completed a CFQ-R between February 2003 and November 2005 during a “well-visit” with an associated pulmonary function test (PFT; between 28 days before and 14 days after the visit). A visit was considered a well-visit if both the visit form and PFT form were not marked as “sick.”

SES was initially evaluated using three indicators: (1) median family income for zip code of residence (2000 US Census); (2) maternal education; and (3) Medicaid or state health insurance coverage. Because all three indicators yielded similar results, in the interest of brevity only SES by Medicaid status is reported here. This SES measure was selected in part because presentation is simpler using a two-category measure.

Patients were categorized as non-Hispanic white, African-American, or Hispanic according to health-care provider identification. A small number of patients classified as “other” were not included in these analyses.

The CFQ-R has generic (Physical Functioning, Social Functioning) and disease-specific (Treatment Burden, Respiratory Symptoms) domains.13 Four versions of the CFQ-R include: (1) CFQ-R Child, an interviewer-administered questionnaire with 35 items for children aged 6 to 11 years; (2) CFQ-R Child for children aged 12 to 13 years, a self-report version of the questionnaire described above; (3) CFQ-R Parent, a proxy measure of HRQOL completed by parents of children aged 6 to 13 years that includes 44 items; and (4) CFQ-R Teen/Adult, a self-report measure for patients aged ≥ 14 years that includes 50 items. Scores are standardized on a 100-point scale, with higher scores indicating better HRQOL.

Statistical Analysis

Data from adolescents (aged 14-17 years) and adults (aged ≥ 18 years) were analyzed separately to evaluate differences between these two developmental ages. Demographic and clinical characteristics were assessed at the univariate level by race/ethnicity and by Medicaid status. Differences among race/ethnicity groups and between Medicaid groups were evaluated using the χ2 test and one-way analysis of variance F-test for categorical and continuous variables. Tukey-adjusted least-squares mean differences in CFQ-R scores among race/ethnicity categories were calculated before and after controlling for SES. A series of multivariate models (base + SES, base + race/ethnicity, and base + SES + race/ethnicity) were used to evaluate the contribution of SES and minority status to HRQOL outcomes after controlling for a base model of CF-specific clinical variables. The base model included gender, FEV1 percent predicted, weight-for-age z score, height-for-age z score, BMI, presence of Pseudomonas aeruginosa (Pa) in airway culture, and pancreatic enzyme use. Centers for Disease Control growth chart means and standard deviations for 20-year-olds were used to calculate z scores for patients ≥ 20 years of age. To estimate the effect size of Medicaid status on CFQ-R, differences in scores between SES groups were calculated three ways: unadjusted, adjusted for the base model, and adjusted for the base model + race/ethnicity. Statistical analyses were performed using SAS Version 9.1 (SAS Institute Inc., Cary, NC).

Of the 32,585 patients enrolled in ESCF, 8,590 completed a CFQ-R. Limiting data to well-visits yielded 2,102 adults, 930 adolescents, and 1,719 children with CFQ-R forms. Parents completed 1,826 forms.

Demographic and medical information showed few differences between well-visit patients who completed the CFQ-R (n = 4,751) and similarly selected ESCF patients who did not complete questionnaires (n = 4,945). Patients completing the CFQ-R had a higher average weight-for-age z score, were less likely to be Hispanic, and if children, were less likely to be Medicaid recipients.

Univariate and Bivariate Analyses

Medicaid patients at all ages had worse lung function and lower height-for-age z scores (Table 1). Younger children on Medicaid were more likely to have positive Pa cultures during the previous year. Adolescents and adults on Medicaid had lower weight-for-age z scores. African-American and Hispanic children and teens generally had worse lung function and lower height than their non-Hispanic white counterparts, but these disparities were not observed in the adult group (Table 2). African-American or Hispanic patients of all ages were more likely to be poor, as indicated by all three SES indicators.

Table Graphic Jump Location
Table 1 —Demographic and Clinical Characteristics by Medicaid Status

Values are mean ± SD except where noted otherwise. z scores for patients > 20 y of age were calculated using the Centers for Disease Control growth chart means and standard deviations for 20-y-olds. P values were derived from χ2 test and Student t test for categorical and continuous variables, respectively, and are provided for descriptive purposes.

a 

P < .001.

b 

P < .05.

c 

P < .01.

Table Graphic Jump Location
Table 2 —Demographic and Clinical Characteristics by Race/Ethnicity

Values are mean ± SD except where noted otherwise. z scores for patients > 20 y of age were calculated using the Centers for Disease Control growth chart means and standard deviations for 20-y-olds. P values were derived from χ2 test and one-way analysis of variation F-test for categorical and continuous variables, respectively, and are provided for descriptive purposes.

a 

P < .001.

b 

P < .05.

c 

P < .01.

Children from low vs high SES families reported worse CFQ-R scores across all domains except Eating and Digestion (Table 3). Similarly, parents in the low vs high SES groups reported lower scores for their children on all scales except eating and weight. Although fewer differences were found for low SES adolescents, they reported worse functioning on six of 12 scales: physical, social functioning, treatment burden, respiratory functioning, health perceptions, and role functioning. Adults with low SES reported worse HRQOL across all domains except Digestion.

Table Graphic Jump Location
Table 3 —Cystic Fibrosis Questionnaire-Revised Score by Respondent Group and Medicaid Status

Values are mean ± SD. P values were derived from Student t test and are provided for descriptive purposes. CFQ-R 5 Cystic Fibrosis Questionnaire-Revised; NI 5 not included in CFQ-R for respondent group.

a 

P < .001.

b 

P < .05.

Comparisons of children’s CFQ-R scores by race/ethnicity revealed worse scores for Hispanic children on the body image and eating scales than non-Hispanic white children (P < .05); after accounting for SES, these Tukey-adjusted comparisons remained statistically significant. African-American children reported worse physical and social functioning than non-Hispanic white children; however, after adjusting for SES, differences in physical functioning were no longer statistically different (Table 4, online supplement).

Table Graphic Jump Location
Table 4 —CFQ-R by Race

Values are mean ± SD except where otherwise noted. See Table 3 for expansion of abbreviations.

a 

Significantly different (Tukey-adjusted P < .05) from white (non-Hispanic) when not controlling for Medicaid status.

b 

Significantly different (Tukey-adjusted P < .05) from white (non-Hispanic) after controlling for Medicaid status.

c 

Hispanic was significantly different (Tukey-adjusted P < .05) from African-American (non-Hispanic) after controlling for Medicaid status.

Parents of Hispanic children reported worse physical functioning and respiratory symptoms than parents of non-Hispanic white children, but better Digestion than parents of non-Hispanic white and African-American children (Table 4, online supplement). After controlling for SES, these differences remained. Parents of African-American children reported worse HRQOL on the physical and school functioning scales than non-Hispanic white parents; however, after controlling for SES, these differences were no longer statistically significant.

Compared with non-Hispanic whites, Hispanic teens reported significantly worse HRQOL on the physical, social, body image, health perceptions, and role functioning scales (Table 4, online supplement). After controlling for SES, these differences remained statistically significant. African-American teens reported significantly worse scores on the social scale than non-Hispanic white teens and these scores remained statistically different after controlling for SES.

Compared with non-Hispanic whites, Hispanic adults reported worse scores on the physical functioning, emotional functioning, and social scales; however, only the emotional functioning scale remained statistically significant after controlling for SES. Hispanic adults also reported better weight scores than African-American adults after controlling for SES. After controlling for SES, African-American adults reported worse scores on the social functioning and weight scales than non-Hispanic whites and worse weight scores than Hispanic adults (Table 4).

Multivariable Models
Child:

The proportion of variance explained by our models (R2) for the CFQ-R scales ranged from 1% to 11% (Fig 1). As expected, the base model of clinical variables (including gender, FEV1, weight-for-age z score, height-for-age z score, BMI, presence of Pa in airway culture, and pancreatic enzyme use) accounted for a substantial proportion of the explained variance across all CFQ-R scales, but provided a lower contribution for digestion (47%), vitality (47%), social functioning (37%), and treatment burden (33%). Clinical variables were strongly associated with the body image (93%), respiratory (93%), and eating (92%) scales. SES accounted for relatively high proportions of the explained variance (range 21% to 63%) and children reported lower HRQOL scores in all domains except eating, body image, and respiratory symptoms. After accounting for SES, Tukey-adjusted comparisons indicated that African-American children reported worse social functioning than both non-Hispanic white and Hispanic children (online supplement).

Figure Jump LinkFigure 1. Overall R2 values (percentage of variance explained) from multivariate linear models for each CFQ-R scale for parent/child (at the bottom of each bar). Stacked bars represent percentage of explained variance associated with base variables (FEV1% predicted, nutritional indices, gender, presence of Pseudomonas, and use of pancreatic enzymes), Medicaid status, race/ethnicity, and the overlap between Medicaid status and race/ethnicity. CFQ-R 5 Cystic Fibrosis Questionnaire-Revised.Grahic Jump Location
Parent:

The R2 values for the CFQ-R scales ranged from 2% to 22% (Fig 1). The base model of clinical variables accounted for a substantial proportion of the explained variance across all CFQ-R scales, but provided a lower contribution for emotional functioning (42%) and school functioning (45%). Clinical variables were strongly associated with weight (100%), body image (99%), eating (96%), respiratory symptoms (87%), and physical functioning (82%). Parents from low SES backgrounds reported lower HRQOL scores for their children across all domains, except eating and weight (Table 3). After controlling for SES, parents of Hispanic children with CF reported worse physical functioning but better digestion than parents of non-Hispanic white and African-American children (Table 4, online supplement).

Adolescent:

The R2 values for the CFQ-R scales ranged from 3% to 22% (Fig 2). The base model of clinical variables accounted for a substantial proportion of the explained variance across all CFQ-R scales, but provided a lower contribution for social functioning (36%). Clinical variables were strongly associated with weight (98%), physical functioning (91%), respiratory symptoms (97%), body image (94%), emotional functioning (94%), health (94%), and eating (94%). Low SES was significantly associated with worse HRQOL scores on the physical and role functioning scales (P < .001, Table 3). After controlling for SES, both Hispanic and African-American teens reported worse social functioning; Hispanic teens also reported worse role functioning than African-American and non-Hispanic white teens (Table 4, online supplement).

Figure Jump LinkFigure 2. Overall R2 values (percentage of variance explained) from multivariate linear models for each CFQ-R scale for adult/teen (at the bottom of each bar). Stacked bars represent percentage of explained variance associated with base variables (FEV1% predicted, nutritional indices, gender, presence of Pseudomonas, and use of pancreatic enzymes), Medicaid status, race/ethnicity, and the overlap between Medicaid status and race/ethnicity. See Figure 1 legend for expansion of abbreviations.Grahic Jump Location
Adult:

The R2 values for the CFQ-R scales ranged from 2% to 21%. The base model of clinical variables accounted for a substantial proportion of the explained variance across all CFQ-R scales, but provided a lower contribution for emotional functioning (41%). Clinical variables were strongly associated with weight (97%), body image (96%), respiratory symptoms (96%), treatment burden (95%), and physical functioning (91%). Low SES was associated with significantly worse scores on all CFQ-R scales except digestion (Table 3). After controlling for SES, Hispanic adults reported worse HRQOL scores on the emotion scale than non-Hispanic white adults, and African-American adults reported lower perceptions of Weight than either Hispanic or non-Hispanic white adults (Table 4, online supplement).

This study examined the effects of SES and race/ethnicity on HRQOL in patients with CF. Clinically stable patients were selected to provide an opportunity to study the effects of SES and minority status on HRQOL. As expected, the base model of clinical measures accounted for a substantial proportion of the explained variance in most CFQ-R domains (physical functioning, respiratory, body image, and weight) across all ages. For adolescents and adults, respiratory symptoms were explained almost entirely by these markers. Low SES and minority status were strongly associated with worse patient-reported outcomes before and after controlling for the base model.

These results extend the findings of Schechter et al2 and O’Connor et al3 regarding the relationship between demographic factors and outcomes for patients with CF. We confirm that low SES was associated with worse pulmonary function, lower height and weight, and greater likelihood of Pa. Worse clinical outcomes were also found in minority children and adolescents but not adults. Patient-reported outcomes were also worse in this vulnerable population, but surprisingly, low SES and minority status were associated with lower HRQOL scores across a number of domains even when controlling for the disparities in clinical outcomes. Furthermore, the effects of SES and minority status were largely independent and additive. To our knowledge, this is one of the few studies in the literature that has attempted to disentangle the effects of economic disadvantage and minority status.

In general, low SES was associated with worse HRQOL scores for children, parents, and adults for all domains except those related to eating and weight, whereas for adolescents, low SES was mainly associated with worse physical and role domain scores. As adolescents become more independent, the effects of parental SES may diminish, whereas the effects of minority status may increase, as seen in the large differences (ie, generally more than 10 points) in areas of functioning that are influenced by peer relationships (eg, social and role functioning).

The effects of minority status on HRQOL were more complex. In general, after accounting for the effects of disease severity and SES, membership in a racial or ethnic minority was associated with worse social and emotional functioning. Hispanic patients tended to report worse HRQOL than African-American patients, particularly in adulthood, with one exception: African-American adults reported worse Weight scores. These negative effects of minority status on social functioning may be due to the relative rarity of CF among African-Americans and its more recent recognition among Hispanic families. A lack of familiarity with the disease may lead to social stigma, isolation, and reduced community support. There may also be cultural differences in families’ views of chronic illness, and they may face unique challenges when interacting with the health-care system.1

The reasons patients from low SES backgrounds experience more severe consequences of their disease are unclear, but it is possible that both poverty and less education are associated with detrimental environmental influences, health behaviors, and difficulties accessing optimal health care.14 Prior studies have failed to show that patients with CF from low SES backgrounds experience barriers in access to care or deficiencies in care.15,16 However, SES and education may exert their effects through other mechanisms, such as increased family stress, exposure to pollution and tobacco smoke, and less well-developed disease management skills.2,3

The most appropriate measure of SES is controversial,17,18 and although we initially tested our hypotheses using three different indicators of SES, the trends were similar for all three measures. Medicaid insurance status was selected for the report because it was available for almost all patients in the ESCF database. All available SES measures have some weaknesses, including this one. Although Medicaid eligibility is linked to federal guidelines and family income, different states may use different criteria. Medical expenses are typically considered in determining eligibility19; hence, sicker patients are more likely to be covered.

This study had several limitations. The African-American and Hispanic groups were small, possibly limiting our ability to detect some effects. A larger sample might have revealed an even greater number of negative effects for race and ethnicity. Only stable patients who were willing to complete the CFQ-R questionnaire were included. Finally, we tested only cross-sectional associations between poverty, minority status, health, and quality-of-life outcomes. These analyses cannot determine the causal ordering of these effects.

In conclusion, low SES and minority status were associated with worse health outcomes and lower HRQOL scores for patients with CF. These results should heighten awareness of the greater health and social risks faced by patients who are economically disadvantaged and/or members of a minority community. Although BMI did not differ significantly between the groups based on SES or minority status, adolescents and adults from low SES backgrounds had lower weight-for-age z scores, and SES also appeared to affect the body image, eating, and weight scores on the CFQ-R. Children and adolescents with CF from Hispanic backgrounds also had worse Body Image scores than white children and adolescents with CF, and Hispanic children with CF reported worse eating disturbances than white children with CF. Thus, interventions focusing on better nutrition, adherence to treatment regimens, and greater social support appear to be critical.5 The CFQ-R revealed effects that were consistent with those observed for patients’ clinical outcomes and exposed effects in the psychosocial domain that have not been previously identified (eg, concerns about body image, and social and role functioning).

Author contributions:Dr Quittner: contributed to the study concept and design, analysis and interpretation of data, drafting of the manuscript, and final approval of the manuscript.

Dr Schechter: contributed to the study concept and design, analysis and interpretation of data, drafting of the manuscript, and final approval of the manuscript.

Mr Rasouliyan: contributed to the study concept and design, analysis and interpretation of data, drafting of the manuscript, and final approval of the manuscript.

Dr Haselkorn: contributed to the study concept and design, analysis and interpretation of data, drafting of the manuscript, and final approval of the manuscript.

Mr Pasta: contributed to the study concept and design, analysis and interpretation of data, drafting of the manuscript, and final approval of the manuscript.

Dr Wagener: contributed to the study concept and design, analysis and interpretation of data, drafting of the manuscript, and final approval of the manuscript.

Financial/nonfinancial disclosures: The authors have reported to CHEST the following conflicts of interest: Drs Quittner, Schechter, and Wagener have received honoraria from Genentech during the last 3 years to attend meetings as members of the North American Scientific Advisory Group for the Epidemiologic Study of Cystic Fibrosis (ESCF) and their respective institutions previously received grant support from Genentech, Inc., for participating in the study. No honoraria, grant, or other form of payment was given to any of these authors to produce this manuscript. Messrs Rasouliyan and Pasta are employees of ICON Clinical Research. ICON Clinical Research was paid by Genentech for providing biostatistical and analytical services for ESCF. Dr Haselkorn is an employee of EpiMetrix, which was paid by Genentech to participate in the interpretation of the data and writing of the manuscript. The decision to submit the manuscript was made by the authors and was approved by Genentech, Inc.

Other contributions: The ESCF is fully supported by Genentech, Inc., South San Francisco, CA. The authors gratefully acknowledge the participation of the more than 400 site investigators and coordinators in ESCF in collecting this comprehensive database.

CF

cystic fibrosis

CFQ-R

Cystic Fibrosis Questionnaire-Revised

ESCF

Epidemiologic Study of Cystic Fibrosis

HRQOL

health-related quality of life

Pa

Pseudomonas aeruginosa

PFT

pulmonary function test

SES

socioeconomic status

Hamosh A, FitzSimmons SC, Macek M Jr, Knowles MR, Rosenstein BJ, Cutting GR. Comparison of the clinical manifestations of cystic fibrosis in black and white patients. J Pediatr. 1998;1322:255-259. [CrossRef] [PubMed]
 
Schechter MS, Shelton BJ, Margolis PA, Fitzsimmons SC. The association of socioeconomic status with outcomes in cystic fibrosis patients in the United States. Am J Respir Crit Care Med. 2001;1636:1331-1337. [PubMed]
 
O’Connor GT, Quinton HB, Kahn R, et al; Northern New England Cystic Fibrosis Consortium Northern New England Cystic Fibrosis Consortium Case-mix adjustment for evaluation of mortality in cystic fibrosis. Pediatr Pulmonol. 2002;332:99-105. [CrossRef] [PubMed]
 
Britto MT, Kotagal UR, Hornung RW, Atherton HD, Tsevat J, Wilmott RW. Impact of recent pulmonary exacerbations on quality of life in patients with cystic fibrosis. Chest. 2002;1211:64-72. [CrossRef] [PubMed]
 
Quittner AL, Barker DH, Marciel KK, et al;Roberts M. Cystic fibrosis: a model for drug discovery and patient care. Handbook of Pediatric Psychology. 2009;4th ed New York, NY Guilford Press:271-286
 
Goss CH, Quittner AL. Patient-reported outcomes in cystic fibrosis. Proc Am Thorac Soc. 2007;44:378-386. [CrossRef] [PubMed]
 
Turner RR, Quittner AL, Parasuraman BM, Kallich JD, Cleeland CS.Mayo/FDA Patient-Reported Outcomes Consensus Meeting GroupTurner RR.Quittner AL.Parasuraman BM.Kallich JD.Cleeland CS. Mayo/FDA Patient-Reported Outcomes Consensus Meeting Group Patient-reported outcomes: instrument development and selection issues. Value Health. 2007;10suppl 2:S86-S93. [CrossRef] [PubMed]
 
Morgan WJ, Butler SM, Johnson CA, et al. Epidemiologic study of cystic fibrosis: design and implementation of a prospective, multicenter, observational study of patients with cystic fibrosis in the U.S. and Canada. Pediatr Pulmonol. 1999;284:231-241. [CrossRef] [PubMed]
 
Modi AC, Quittner AL. Validation of a disease-specific measure of health-related quality of life for children with cystic fibrosis. J Pediatr Psychol. 2003;288:535-545. [CrossRef] [PubMed]
 
Quittner AL, Buu A, Messer MA, Modi AC, Watrous M. Development and validation of The Cystic Fibrosis Questionnaire in the United States: a health-related quality-of-life measure for cystic fibrosis. Chest. 2005;1284:2347-2354. [CrossRef] [PubMed]
 
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Schechter MS, Pasta D, Morgan WJ, et al. Socioeconomic status and the likelihood of antibiotic treatment for pulmonary exacerbations [abstract]. Pediatr Pulmonol. 2005;28suppl:331
 
Schechter MS, Silva SJ, Morgan WJ, et al. Association of socioeconomic status with outpatient monitoring and the use of chronic CF therapies [abstract]. Pediatr Pulmonol. 2005;28suppl:330
 
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Schechter MS. Non-genetic influences on cystic fibrosis lung disease: the role of sociodemographic characteristics, environmental exposures, and healthcare interventions. Semin Respir Crit Care Med. 2003;246:639-652. [CrossRef] [PubMed]
 
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Holahan J, Rowland D, Feder J, Heslam D. Explaining the recent growth in Medicaid spending. Health Aff (Millwood). 1993;123:177-193. [CrossRef] [PubMed]
 

Figures

Figure Jump LinkFigure 1. Overall R2 values (percentage of variance explained) from multivariate linear models for each CFQ-R scale for parent/child (at the bottom of each bar). Stacked bars represent percentage of explained variance associated with base variables (FEV1% predicted, nutritional indices, gender, presence of Pseudomonas, and use of pancreatic enzymes), Medicaid status, race/ethnicity, and the overlap between Medicaid status and race/ethnicity. CFQ-R 5 Cystic Fibrosis Questionnaire-Revised.Grahic Jump Location
Figure Jump LinkFigure 2. Overall R2 values (percentage of variance explained) from multivariate linear models for each CFQ-R scale for adult/teen (at the bottom of each bar). Stacked bars represent percentage of explained variance associated with base variables (FEV1% predicted, nutritional indices, gender, presence of Pseudomonas, and use of pancreatic enzymes), Medicaid status, race/ethnicity, and the overlap between Medicaid status and race/ethnicity. See Figure 1 legend for expansion of abbreviations.Grahic Jump Location

Tables

Table Graphic Jump Location
Table 1 —Demographic and Clinical Characteristics by Medicaid Status

Values are mean ± SD except where noted otherwise. z scores for patients > 20 y of age were calculated using the Centers for Disease Control growth chart means and standard deviations for 20-y-olds. P values were derived from χ2 test and Student t test for categorical and continuous variables, respectively, and are provided for descriptive purposes.

a 

P < .001.

b 

P < .05.

c 

P < .01.

Table Graphic Jump Location
Table 2 —Demographic and Clinical Characteristics by Race/Ethnicity

Values are mean ± SD except where noted otherwise. z scores for patients > 20 y of age were calculated using the Centers for Disease Control growth chart means and standard deviations for 20-y-olds. P values were derived from χ2 test and one-way analysis of variation F-test for categorical and continuous variables, respectively, and are provided for descriptive purposes.

a 

P < .001.

b 

P < .05.

c 

P < .01.

Table Graphic Jump Location
Table 3 —Cystic Fibrosis Questionnaire-Revised Score by Respondent Group and Medicaid Status

Values are mean ± SD. P values were derived from Student t test and are provided for descriptive purposes. CFQ-R 5 Cystic Fibrosis Questionnaire-Revised; NI 5 not included in CFQ-R for respondent group.

a 

P < .001.

b 

P < .05.

Table Graphic Jump Location
Table 4 —CFQ-R by Race

Values are mean ± SD except where otherwise noted. See Table 3 for expansion of abbreviations.

a 

Significantly different (Tukey-adjusted P < .05) from white (non-Hispanic) when not controlling for Medicaid status.

b 

Significantly different (Tukey-adjusted P < .05) from white (non-Hispanic) after controlling for Medicaid status.

c 

Hispanic was significantly different (Tukey-adjusted P < .05) from African-American (non-Hispanic) after controlling for Medicaid status.

References

Hamosh A, FitzSimmons SC, Macek M Jr, Knowles MR, Rosenstein BJ, Cutting GR. Comparison of the clinical manifestations of cystic fibrosis in black and white patients. J Pediatr. 1998;1322:255-259. [CrossRef] [PubMed]
 
Schechter MS, Shelton BJ, Margolis PA, Fitzsimmons SC. The association of socioeconomic status with outcomes in cystic fibrosis patients in the United States. Am J Respir Crit Care Med. 2001;1636:1331-1337. [PubMed]
 
O’Connor GT, Quinton HB, Kahn R, et al; Northern New England Cystic Fibrosis Consortium Northern New England Cystic Fibrosis Consortium Case-mix adjustment for evaluation of mortality in cystic fibrosis. Pediatr Pulmonol. 2002;332:99-105. [CrossRef] [PubMed]
 
Britto MT, Kotagal UR, Hornung RW, Atherton HD, Tsevat J, Wilmott RW. Impact of recent pulmonary exacerbations on quality of life in patients with cystic fibrosis. Chest. 2002;1211:64-72. [CrossRef] [PubMed]
 
Quittner AL, Barker DH, Marciel KK, et al;Roberts M. Cystic fibrosis: a model for drug discovery and patient care. Handbook of Pediatric Psychology. 2009;4th ed New York, NY Guilford Press:271-286
 
Goss CH, Quittner AL. Patient-reported outcomes in cystic fibrosis. Proc Am Thorac Soc. 2007;44:378-386. [CrossRef] [PubMed]
 
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Modi AC, Quittner AL. Validation of a disease-specific measure of health-related quality of life for children with cystic fibrosis. J Pediatr Psychol. 2003;288:535-545. [CrossRef] [PubMed]
 
Quittner AL, Buu A, Messer MA, Modi AC, Watrous M. Development and validation of The Cystic Fibrosis Questionnaire in the United States: a health-related quality-of-life measure for cystic fibrosis. Chest. 2005;1284:2347-2354. [CrossRef] [PubMed]
 
Brown R, Fuemmeler B, Forti E.Roberts M. Racial and ethnic health disparities and access to care. Handbook of Pediatric Psychology. 2003;3rd ed New York, NY Guilford Press
 
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Schechter MS, Silva SJ, Morgan WJ, et al. Association of socioeconomic status with outpatient monitoring and the use of chronic CF therapies [abstract]. Pediatr Pulmonol. 2005;28suppl:330
 
Modi A, Quittner AL. Utilizing computerized phone diary procedures to assess health behaviors in family and social contexts. Child Health Care. 2006;351:29-45. [CrossRef]
 
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NOTE:
Citing articles are presented as examples only. In non-demo SCM6 implementation, integration with CrossRef’s "Cited By" API will populate this tab (http://www.crossref.org/citedby.html).
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