Comparing discriminative validity between a disease-specific and a general health scale in patients with moderate asthma

Cannabidiolic acid exhibits entourage-like improvements of anticonvulsant activity in an acute rat model of seizures

OBJECTIVES

Cannabidiolic acid (CBDa) is pharmacologically unique from cannabidiol (CBD), but its chemical instability poses challenges for potential clinical utility. Here, we used magnesium ions to stabilize two cannabidiolic acid-enriched hemp extracts (Mg-CBDa and Chylobinoid, the latter of which also contains minor cannabinoid constituents) and compared their anticonvulsant activities with CBD in the maximal electroshock seizure test (MES) in rats.

METHODS

Sprague-Dawley rats received intraperitoneal (i.p.) injections of Chylobinoid, Mg-CBDa, or CBD at varying doses at discrete time points. Rats were challenged with a 0.2 s, 60 Hz, 150 mA corneal stimulation and evaluated for resultant hindlimb tonic extension. Dose-response relationships were calculated using Probit analysis and statistical significance was assessed with a two-sample z-test.

RESULTS

Median effective doses (ED₅₀) and 95 % confidence intervals were calculated for each compound and adjusted according to percentage of CBDa (w/w): Chylobinoid: 76.7 (51.7-109.2) mg/kg. Mg-CBDa: 115.4 (98.8-140.9) mg/kg. CBD: 68.8 (56.6-80.0) mg/kg.

SIGNIFICANCE

CBDa-enriched hemp extracts exhibited dose-dependent protection in the MES model at doses comparable, but not more effective than, CBD. Chylobinoid was more effective than Mg-CBDa despite lower CBDa content. Test compounds should be compared by sub-chronic dosing in the MES test in order to assess safety and pharmacokinetic profiles. CBDa should be evaluated in pharmacoresistant and chronic animal models of epilepsy.

Validation of the short-form Health Literacy Scale in patients with stroke

OBJECTIVE

We aimed to validate a Mandarin version of the short-form Health Literacy Scale (SHEAL) in patients with stroke.

METHODS

Each patient with stroke was interviewed with the SHEAL. The Public Stroke Knowledge Quiz (PSKQ) was administered as a criterion for examining the convergent validity of the SHEAL. The discriminative validity of the SHEAL was determined with age and education level as independent grouping variables.

RESULTS

A total of 87 patients with stroke volunteered to participate in this prospective study. The SHEAL demonstrated sufficient internal consistency reliability (alpha=0.82) and high correlation with the PSKQ (r=0.62). The SHEAL scores between different age groups and education level groups were significantly different. The SHEAL, however, showed a notable ceiling effect (24.1% of the participants), indicating that the SHEAL cannot differentiate level of health literacy between individuals with high health literacy.

CONCLUSION

The internal consistency reliability, convergent validity, and discriminative validity of the SHEAL were adequate. However, the internal consistency reliability and ceiling effect of the SHEAL need to be improved.

PRACTICE IMPLICATIONS

The SHEAL has shown its potential for assessing the health literacy of patients with stroke for research purposes. For clinical usage, however, the SHEAL should be used with caution.

Abbreviated World Health Organization Quality of Life questionnaire (WHOQOL-Bref) in north Indian patients with bronchial asthma: an evaluation using Rasch analysis

BACKGROUND

There is no disease-specific instrument to describe health-related quality of life (HRQoL) in Indian patients with asthma. However, an abbreviated World Health Organization Quality of Life questionnaire (WHOQOL-Bref), a generic Hindi HRQoL measure, has been developed and validated in India.

AIMS

To evaluate the WHOQOL-Bref in adult patients with asthma and to test possible modifications to the instrument to improve its psychometric adequacy.

METHODS

Sixty-seven patients with asthma completed the WHOQOL-Bref. Rasch analysis was used to explore the psychometric performance of the four domains (physical, psychological, social relationships and environment) of the scale. Overall fit of data to model expectations, appropriate category ordering, presence of differential item functioning, individual item fit and targeting of item difficulty to patient ability were explored for each domain. Item deletion and rescoring were applied to misfitting items to improve overall performance.

RESULTS

The overall fit of the WHOQOL-Bref data was adequate. Item 3 (pain prevents doing work) displayed a large positive fit residual value (indicating violation of unidimensionality), resulting in poor construct validity for the physical domain. No item exhibited differential item functioning. Ten items had disordered thresholds. The WHOQOL-Bref was modified by dropping item 3 and rescoring category structures of 16 items. The modified scale had good construct validity for all domains, ordered thresholds for all items and good targeting of items to persons.

CONCLUSIONS

The WHOQOL-Bref performed inadequately in describing HRQoL in the asthma patients studied. However, when modified by Rasch analysis, the scale proved better than the original scale.

Asthma outcomes: quality of life

BACKGROUND

"Asthma-related quality of life" (QOL) refers to the perceived impact that asthma has on the patient's QOL.

OBJECTIVE

National Institutes of Health institutes and other federal agencies convened an expert group to recommend standardized measures of the impact of asthma on QOL for use in future asthma clinical research.

METHODS

We reviewed published documentation regarding the development and psychometric evaluation; clinical research use since 2000; and extent to which the content of each existing QOL instrument provides a unique, reliable, and valid assessment of the intended construct. We classified instruments as core (required in future studies), supplemental (used according to the study's aims and standardized), or emerging (requiring validation and standardization). This work was discussed at an National Institutes of Health-organized workshop convened in March 2010 and finalized in September 2011.

RESULTS

Eleven instruments for adults and 6 for children were identified for review. None qualified as core instruments because they predominantly measured indicators of asthma control (symptoms and/or functional status); failed to provide a distinct, reliable score measuring all key dimensions of the intended construct; and/or lacked adequate psychometric data.

CONCLUSIONS

In the absence of existing instruments that meet the stated criteria, currently available instruments are classified as either supplemental or emerging. Research is strongly recommended to develop and evaluate instruments that provide a distinct, reliable measure of the patient's perception of the impact of asthma on all of the key dimensions of QOL, an important outcome that is not captured in other outcome measures.

Determinants of Quality of Life Among People with Asthma: Findings from the Behavioral Risk Factor Surveillance System

Asthma is a major contributor to impaired quality of life in the U.S. population. Little is known about population-based determinants of quality of life among people with asthma, however. Using data from the 2000 Behavioral Risk Factor Surveillance System, we examined the associations between selected sociodemographic, behavioral, and other determinants and quality of life among 12,111 participants with current asthma. In multiple logistical regression models, three variables--employment status, smoking status, and physical activity--were significantly associated with all measures of impaired quality of life (poor or fair health, > or = 14 physically unhealthy days, > 14 mentally unhealthy days, > or = 14 activity limitation days, or > or = 14 physically or mentally unhealthy days). Education was significantly and inversely related to impaired quality of life for all measures except activity limitation days. Men were less likely than women to report having > or = 14 physically unhealthy days, > or = 14 mentally unhealthy days, or > or = 14 physically or mentally unhealthy days. Compared with whites, Hispanics were more likely to report being in poor or fair health, and African Americans were less likely to report having > or = 14 physically unhealthy days or > or = 14 physically or mentally unhealthy days. In addition, participants with lower incomes were more likely to report impaired quality of life for three measures (general health status, > or = 14 physically unhealthy days, and activity limitation days). The heaviest participants were more likely to be in poor or fair health or to report having more > or = 14 physically unhealthy days, or > or = 14 physically or mentally unhealthy days. Insurance coverage and the time since their last routine checkup were not significantly associated with any of the quality-of-life measures. These results show that three potentially modifiable factors (smoking status, physical activity, body mass index) are associated with quality of life among persons with asthma. Furthermore, among people with asthma, the elderly, women, poorly educated, and low-income participants are especially likely to experience impaired quality of life.

The linkage between pediatric quality of life and health conditions: establishing clinically meaningful cutoff scores for the PedsQL

OBJECTIVE

To link pediatric health-related quality of life (HRQOL) and health conditions by establishing clinically meaningful cutoff scores for an HRQOL instrument, the Pediatric Quality of Life Inventory (PedsQL).

METHODS

We conducted telephone interviews with 1745 parents whose children were between 2 and 18 years old and enrolled in the Florida KidCare program and Children's Medical Services Network in 2006. Two anchors, the Children with Special Health Care Needs (CSHCN) Screener and the Clinical Risk Groups (CRGs), were used to identify children with special health-care needs or chronic conditions. We established cutoff scores for the PedsQL's physical, emotional, social, school, and total functioning using the areas under the curves (AUCs) to determine the discriminative property of the PedsQL referring to the anchors.

RESULTS

The discriminative property of the PedsQL was superior, especially in total functioning (AUC > 0.7), between children with special health-care needs (based on the CSHCN Screener) and with moderate and major chronic conditions (based on the CRGs) as compared to healthy children. For children <8 years, the recommended cutoff scores for using total functioning to identify CSHCN were 83, 79 for moderate, and 77 for major chronic conditions. For children ≥8 years, the cutoff scores were 78, 76, and 70, respectively.

CONCLUSIONS

Pediatric HRQOL varied with health conditions. Establishing cutoff scores for the PedsQL's total functioning is a valid and convenient means to potentially identify children with special health-care needs or chronic conditions. The cutoff scores can help clinicians to conduct further in-depth clinical assessments.

A qualidade de vida de pessoas com deficiência mental leve

Não é prática comum dar voz a pessoas com deficiência, mesmo quando se trata da investigação de sua própria qualidade de vida. Assim, este estudo teve por objetivo conhecer a opinião de 15 adultos com deficiência mental leve em relação a sua qualidade de vida e a opinião de seus cuidadores também a esse respeito, por meio de um instrumento que avalia a qualidade de vida (WHOQOL-Bref). Os dados foram analisados estatisticamente e comparados. Os resultados mostram que a diferença entre as avaliações foi pequena nas questões referentes à satisfação com os domínios físico, psicológico, das relações sociais e do meio ambiente. A avaliação feita pelas pessoas com deficiência foi apenas ligeiramente superior àquela feita por seus cuidadores. Não houve diferença estatisticamente significativa entre as avaliações, do que se conclui que as pessoas com deficiência mental são capazes de falar de suas próprias vidas de maneira positiva e bastante realista.

Discriminative aspects of SF-36 and QQL-EPM related to asthma control

AIM

To study any discriminative properties of SF-36 and QQL-EPM in stable and non-controlled moderate asthmatic patients.

METHODS

A total of 63 asthmatic patients were assessed regarding asthma symptoms, FEV1 % predicted value, PEF, ED visits and hospitalizations, QQL-EPM and SF-36 questionnaires.

RESULTS

QQL-EPM highlighted significance in all domains to distinguish stable from non-controlled patients (p = 0.0001) while SF-36 was only significant in 3 of its 7 domains (p = 0.009).

CONCLUSION

The study showed that the specific quality of life questionnaire for asthma (QQL-EPM) demonstrates better discriminative properties that characterize asthma control when compared with the more generic SF-36 questionnaire.

Impact of comorbidities on the measurement of health in patients with ankle osteoarthritis

BACKGROUND

Investigators seeking to understand the impact of musculoskeletal disorders commonly use validated outcome instruments to assess the effect of diseases on physical function and quality of life. However, the influence of concomitant systemic or musculoskeletal comorbidities on these scores has not been widely considered in orthopaedic research. The purpose of this study was to determine how morbidity unrelated to the ankle influences the perception of physical function and pain by patients with ankle osteoarthritis.

METHODS

Short Form-36 (SF-36) Physical Component Summary (PCS) and Mental Component Summary (MCS) scores, Ankle Osteoarthritis Scale (AOS) pain scale scores, demographic data, and systemic and musculoskeletal comorbidities were determined prospectively for 195 patients with ankle osteoarthritis and ninety-five age and gender-matched controls. The effect of systemic and musculoskeletal comorbidities on each of the scores was determined.

RESULTS

On the average, patients with ankle osteoarthritis had a relatively normal MCS score (47 +/- 13 points) and a markedly diminished PCS score (32 +/- 8 points). Both of these scores averaged 50 +/- 9 points in the control group. The AOS pain score averaged 61 +/- 23 points in the group with ankle osteoarthritis, whereas it averaged 10 +/- 15 points in the control group. We found the perception of ankle pain by patients with ankle osteoarthritis to be significantly and linearly associated with the number of other musculoskeletal problems (not related to the foot or ankle).

CONCLUSIONS

The degree of physical impairment associated with ankle osteoarthritis, as measured with the SF-36, is equivalent to that reported to be associated with severely disabling medical problems including end-stage kidney disease and congestive heart failure. The perception of ankle health status as measured with a validated, patient-oriented, anatomically specific instrument is influenced by the patients' perception of their overall musculoskeletal comorbidity status. The authors of clinical studies using these instruments should adjust for concomitant musculoskeletal disease.

Long-term follow-up of patients with clubfeet treated with extensive soft-tissue release

BACKGROUND

Although long-term follow-up studies have shown favorable results, in terms of foot function, after treatment of idiopathic clubfoot with serial manipulations and casts, we know of no long-term follow-up studies of patients in whom clubfoot was treated with an extensive surgical soft-tissue release.

METHODS

Forty-five patients (seventy-three feet) in whom idiopathic clubfoot was treated with either a posterior release and plantar fasciotomy (eight patients) or an extensive combined posterior, medial, and lateral release (thirty-seven patients) were followed for a mean of thirty years. Patients were evaluated with detailed examination of the lower extremities, a radiographic evaluation that included grading of osteoarthritis, and three independent quality-of-life questionnaires, including the Short Form-36 Medical Outcomes Study.

RESULTS

At the time of follow-up, the majority of patients in both treatment groups had significant limitation of foot function, which was consistent across the three independent quality-of-life questionnaires. No significant difference between groups was noted with regard to the results of the quality-of-life measures, the range of motion of the ankle or the position of the heel, or the radiographic findings. Six patients who had been treated with only one surgical procedure had better ranges of motion of the ankle and subtalar joints (p < 0.004) than those who had had multiple surgical procedures.

CONCLUSIONS

Many patients with clubfoot treated with an extensive soft-tissue release have poor long-term foot function. We found a correlation between the extent of the soft-tissue release and the degree of functional impairment. Repeated soft-tissue releases can result in a stiff, painful, and arthritic foot and significantly impaired quality of life.

Reliability of AOFAS diabetic foot questionnaire in Charcot arthropathy: stability, internal consistency, and measurable difference

BACKGROUND

The development of Charcot changes is known to be associated with a high rate of recurrent ulceration and amputation. Unfortunately, the effect of Charcot arthropathy on quality of life in diabetic patients has not been systematically studied because of a lack of a disease-specific instrument. The purpose of this study was to develop and test an instrument to evaluate the health-related quality of life of diabetic foot disease.

METHODS

Subjects diagnosed with Charcot arthropathy completed a patient self-administered questionnaire, and clinicians completed an accompanying observational survey. The patient self-administered questionnaire was organized into five general sections: demographics, general health, diabetes-related symptoms, comorbidities, and satisfaction. The scales measured the effect in six health domains: 1) general health, 2) care, 3) worry, 4) sleep, 5) emotion, and 6) physicality. The psychometric properties of the scales were evaluated and the summary scores for the Short-Form Health Survey (SF-36) were compared to published norms for other major medical illnesses.

RESULTS

Of the 89 enrolled patients, 57 who completed the questionnaire on enrollment returned a second completed form at 3-month followup. Over the 3-month followup period most of the patients showed an improvement in the Eichenholtz staging. The internal consistency of most was moderate to high and, in general, the scale scores were stable over 3 months. However, several of the scales suffered from low-ceiling or high-floor effects. Patients with Charcot arthropathy had a much lower physical component score on enrollment than the reported norms for other disease conditions, including diabetes.

CONCLUSIONS

Quality of life represents an important set of outcomes when evaluating the effectiveness of treatment for patients with Charcot arthropathy. This study represents an initial attempt to develop a standardized survey for use with this patient population. Further studies need to be done with larger groups of patients to refine the tool and to begin the validation process. The instrument developed could be used for comparing treatment strategies for Charcot arthropathy.

Different methods to assess quality of life from multiple follow-ups in a longitudinal asthma study

BACKGROUND AND OBJECTIVE

Serial measurements obtained during observational longitudinal studies offer the opportunity to describe the effects of chronic diseases on patient-centered outcomes such as quality of life. The purpose of this study was to assess serial Asthma Quality of Life Questionnaire (AQLQ) and SF-36 scores against a transition item using three methods of data analysis-final minus initial scores, maximum minus minimum scores, and regression line slopes through all scores.

METHODS

Using receiver operating characteristic (ROC) curves, each method of analysis was compared against patients' responses to a global transition question about change in asthma status with responses dichotomized as "stayed the same or got worse" or "improved." A total of 185 patients, mean age 41+/-11 years, 83% women, completed the AQLQ and SF-36 three to seven times at approximately 8-month intervals over a mean of 24.8+/-3.9 months. For the AQLQ, all three methods of data analysis performed well against the transition item with ROC areas highest for the symptoms, activities, and the summary AQLQ scores (0.74-0.78).

RESULTS

Overall, ROC areas increased as the number of observations increased, ranging from 0.78 to 0.93 for the AQLQ summary score for patients with three to six or more assessments, respectively (P =.02). As part of the AQLQ, patients cited specific activities in which they were limited because of asthma. A total of 66 different activities were cited, including limitations in stair climbing, walking, interacting with others, sleeping, and working. In ROC analysis, serial measurements of these items also performed well against the transition item with areas ranging from 0.72 to 0.75 for all three methods of analysis. In contrast, ROC areas for the SF-36 Physical and Mental Component Summary scores were significantly lower, ranging from 0.59 to 0.66 compared to the AQLQ areas, indicating that the generic scale was less responsive than the disease-specific scale (P< or = .01). The three different methods of analysis also provided unique information about the cohort. The final minus initial analysis showed that 63% of patients had clinically important improvements, the maximum minus minimum analysis showed that over 90% of patients had fluctuations in scores that were clinically important, and the slope analysis showed that 79% of patients had an overall trend of improvement.

CONCLUSIONS

This study described possible methods to analyze and present serial data. Additional techniques to assess and interpret serial longitudinal data are needed to comprehensively describe long-term effects of chronic diseases on quality of life.

A comparison of the responsiveness of different generic health status measures in patients with asthma

Generic health status has been recommended to be measured separately from disease-specific health status, because they can yield complementary information. In particular, generic health status can provide comprehensive health ratings across various disorders. However, the weakness with generic measures is that they may be less responsive to clinical changes than disease-specific ones. Therefore, when using generic health status as an endpoint in clinical trials, the instrument to be used is a problem with respect to responsiveness. In the present study, we investigated and compared the responsiveness of health status measures during asthma treatment using three different generic instruments: the Medical Outcomes Study Short Form 36-items Health Survey (SF-36), the Nottingham Health Profile (NHP) and the EQ5D (EuroQoL), as well as one disease-specific instrument, the Asthma Quality of Life Questionnaire (AQLQ). Fifty-four new patients with asthma who consulted our clinic were recruited. The health status measurements were performed on the initial visit, and at 3 and 6 months. All subscales of the SF-36 showed a significant improvement during the first 6 months. Each dimension of the EQ5D showed stronger ceiling effects than the SF-36. With respect to the responsiveness indices, the SF-36 was regarded as more responsive than the NHP or EQ5D utility. The changes in the SF-36 had a weak to moderate correlation with the changes in the AQLQ. In conclusion, the SF-36 had a higher responsiveness for asthma as a generic measure than the NHP or EQ5D, and evaluated different aspects from the AQLQ. The SF-36 can be used effectively in asthma clinical trials.

Construct validity and responsiveness of the Child Health Questionnaire in children with acute asthma

OBJECTIVE

To examine the validity and responsiveness of the Child Health Questionnaire (CHQ-PF28) in the context of acute exacerbation of asthma in children.

DESIGN AND METHODS

This was a prospective cohort study of children age 5 years and older treated for acute asthma at two urban pediatric emergency departments (EDs). At 14 days after the visit, all patients were contacted by telephone and the CHQ-PF28 (modified to have a 2-week recall period) was administered. Poor 14-day outcome was defined as one or more of the following: child or parent missed at least 5 days of school/day care/work; child still having asthma symptoms above baseline at 14 days; or unscheduled care within 7 days after the ED visit.

RESULTS

A total of 732 subjects (median age, 9 years) were enrolled; 622 (85%) had successful follow-up at day 14. At the 14-day follow-up, 254 (43%) were classified as having a poor outcome. The mean physical subscale score of the CHQ-PF28 was 48.2 among those with a good outcome, vs 35.9 among the poor outcome group (difference = 12.3; 95% confidence interval, 10.2 to 14.3). For the psychosocial subscale the average difference between groups was 6.9 (95% confidence interval, 5.1 to 8.7). Among the 146 patients at one site who also had a CHQ score obtained at the initial visit, there was a significant improvement in mean physical subscale score among those with good, but not poor, outcome. However, the relative responsiveness was moderate, with an effect size of only 0.37.

CONCLUSIONS

Both the physical and psychosocial subscales of the CHQ-PF28 administered 14 days after an ED visit for acute exacerbation of asthma are correlated with poor short-term functional outcome, but scores are only moderately responsive to acute changes in functional status.

Self-reported asthma and health-related quality of life: findings from the behavioral risk factor surveillance system

STUDY OBJECTIVES

Few population-based data regarding the impact of asthma on health-related quality of life in the US adult population are available.

DESIGN

Cross-sectional study of participants in 50 states in the United States.

SETTING

Using data from 163,773 adult respondents in the 2000 Behavioral Risk Factor Surveillance System, we examined how self-reported asthma is associated with general self-reported health and four health-related quality-of-life measures.

RESULTS

Participants with self-reported current asthma reported significantly more age-adjusted physically unhealthy days (6.5 days vs 2.9 days, p < 0.001), mentally unhealthy days (5.2 days vs 3.0 days, p < 0.001), days with activity limitation (3.7 days vs 1.6 days, p < 0.001), and unhealthy physical or mental days (10.0 days vs 5.4 days, p < 0.001) in the last 30 days than participants who never had asthma. After adjusting for age, sex, race or ethnicity, educational attainment, employment status, smoking status, physical activity status, and body mass index, the odds ratios among persons with asthma compared with persons who never had asthma, were 2.41 (95% confidence interval [CI], 2.21 to 2.63) for reporting poor or fair self-rated health, 2.26 (95% CI, 2.06 to 2.49) for reporting >or= 14 days of impaired physical health during the previous 30 days, 1.55 (95% CI, 1.40 to 1.72) for reporting >or= 14 days of poor mental health during the previous 30 days, 1.96 (95% CI, 1.73 to 2.21) for reporting >or= 14 activity limitation days, and 1.99 (95% CI, 1.84 to 2.15) for reporting >or= 14 days of physically or mentally unhealthy days during the previous 30 days. Results were consistent for all age groups, for both sexes, and for all race or ethnic groups. Participants who did not currently have asthma, but had it previously, reported having more unhealthy days with all four measures than participants who never had asthma, but fewer than participants who currently had asthma.

CONCLUSIONS

These results provide additional measures to evaluate and monitor the impact of asthma on the health of the US adult population.

Comparison of the responsiveness of different disease-specific health status measures in patients with asthma

BACKGROUND

Disease-specific health status measures are characterized by higher responsiveness than generic measures and may be preferred in clinical trials. However, comparisons of responsiveness between various disease-specific measures have rarely been performed in asthma studies.

STUDY OBJECTIVE

We investigated and compared the responsiveness of health status scores in asthmatic patients during treatment using three different disease-specific measures: the Juniper Asthma Quality of Life Questionnaire (AQLQ), the Living with Asthma Questionnaire (LWAQ), and the Airways Questionnaire 20 (AQ20).

METHODS

We attempted to follow up 170 patients with newly diagnosed asthma over a 6-month period. Patients underwent treatment with inhaled corticosteroids in accordance with the guideline. A health status evaluation using three disease-specific measures, and pulmonary function tests were performed on the initial visit, and at 3 months and 6 months. The effect size and the standardized response mean were used as responsiveness indexes.

RESULTS

A total of 109 patients completed the 6-month follow-up and were then analyzed. All health status scores and FEV(1) measures improved during the first 3 months (p < 0.001). The total of the AQLQ scores showed high responsiveness indexes ranging from 1.28 to 1.46 between baseline and 3 months, and baseline and 6 months. Spearman correlation coefficients were smaller between the change in FEV(1) and the change in the LWAQ. Although the AQ20 also demonstrated high responsiveness, a ceiling effect was indicated.

CONCLUSIONS

The AQLQ was the most responsive measure during asthma treatment. The relationship between the change in airflow limitation and the change in the LWAQ was weaker compared to the AQLQ and the AQ20. Although the AQ20 was also responsive and its simplicity is favorable, the ceiling effect should be considered when using it.

Self-efficacy, depressive symptoms, and patients' expectations predict outcomes in asthma

BACKGROUND

Certain psychosocial variables are relatively unexplored as possible predictors of asthma outcomes.

OBJECTIVE

To determine if asthma self-efficacy, depressive symptoms, and unrealistic expectations predict urgent care use and change in health-related quality of life measured by the Asthma Quality of Life Questionnaire and the SF-36 during 2 years.

RESEARCH DESIGN

Prospective cohort study in a primary care internal medicine practice at a tertiary care center in New York City.

PATIENTS

Adults with moderate asthma who were fluent in either English or Spanish.

MEASUREMENTS

At enrollment patients were interviewed in-person and completed a series of questionnaires including the Asthma Quality of Life Questionnaire (AQLQ), the SF-36, the Asthma Self-efficacy Scale, the Geriatric Depression Scale, and open-ended questions regarding their expectations of treatment. Patients also completed the AQLQ and SF-36 at various time intervals throughout the study and were interviewed by telephone every 3 months to record recent hospitalizations, emergency department visits and nonroutine office visits for asthma.

RESULTS

A total of 224 patients were followed for a mean of 23.8 months. In hierarchical analysis, independent predictors of lower AQLQ scores were less self-efficacy, more depressive symptoms, expecting to be cured of asthma, requiring methylxanthines, being Hispanic or black, and having difficult or very difficult access to asthma care (all at P <0.05). Similar predictors were found for lower SF-36 scores. Another outcome, use of urgent care, was required by 60% of patients during the study period. Predictors of using urgent care were having more depressive symptoms, expecting a cure, being female, requiring oral beta-agonists, and having a history of prior hospitalizations for asthma (all at P <0.05).

CONCLUSIONS

Less asthma self-efficacy, more depressive symptoms, and unrealistic expectations predict worse asthma outcomes. These relatively unexplored patient-centered variables in asthma are potentially modifiable and may offer new ways to intervene to improve asthma outcomes.