Individual Differences in Working Memory and the N2pc.

The lateralized ERP N2pc component has been shown to be an effective marker of attentional object selection when elicited in a visual search task, specifically reflecting the selection of a target item among distractors. Moreover, when targets are known in advance, the visual search process is guided by representations of target features held in working memory at the time of search, thus guiding attention to objects with target-matching features. Previous studies have shown that manipulating working memory availability via concurrent tasks or within task manipulations influences visual search performance and the N2pc. Other studies have indicated that visual (non-spatial) vs. spatial working memory manipulations have differential contributions to visual search. To investigate this the current study assesses participants' visual and spatial working memory ability independent of the visual search task to determine whether such individual differences in working memory affect task performance and the N2pc. Participants (n = 205) completed a visual search task to elicit the N2pc and separate visual working memory (VWM) and spatial working memory (SPWM) assessments. Greater SPWM, but not VWM, ability is correlated with and predicts higher visual search accuracy and greater N2pc amplitudes. Neither VWM nor SPWM was related to N2pc latency. These results provide additional support to prior behavioral and neural visual search findings that spatial WM availability, whether as an ability of the participant's processing system or based on task demands, plays an important role in efficient visual search.

Asthma Control Questionnaire in children: validation, measurement properties, interpretation.

The Asthma Control Questionnaire (ACQ) has been validated in adults to measure the primary goal of management (minimisation of symptoms, activity limitations, short-acting ß2-agonist use and airway narrowing). The present study evaluated the validity, measurement properties and interpretability of the ACQ in children aged 6-16 yrs. 35 children attended clinic on three occasions (0, 1 and 4 weeks) and completed the ACQ, Mini Paediatric Asthma Quality of Life Questionnaire and the Royal College of Physicians' "Three Questions". Parents completed the Paediatric Asthma Caregiver's Quality of Life Questionnaire. Between visits, children completed the Asthma Control Diary and measured peak expiratory flow. At weeks 1 and 4, clinicians and parents completed Global Rating of Change Questionnaires. All patients completed the study. 19 children were stable between two assessments and provided evidence of good test-retest reliability (intraclass correlation coefficient 0.79). The ACQ was responsive to change in asthma control (p = 0.026) and the mean ± sd Minimal Important Difference was 0.52 ± 0.45. Both cross-sectional and longitudinal correlations between the ACQ and the other outcomes were close to predicted and provided evidence that the ACQ measures asthma control in children. The ACQ has strong measurement properties and is valid for use in children aged 6-16 yrs. In children aged 6-10 yrs, it must be administered by a trained interviewer.

Validation of an electronic version of the Mini Asthma Quality of Life Questionnaire.

BACKGROUND: The Mini Asthma Quality of Life Questionnaire (MiniAQLQ) is a validated disease-specific quality of life (QOL) paper (p) questionnaire. Electronic (e) versions enable inclusion of asthma QOL in electronic medical records and research databases. PURPOSE: To validate an e-version of the MiniAQLQ, compare time required for completion of e- and p-versions, and determine which version participants prefer. METHODS: Adults with stable asthma were randomized to complete either the e- or p-MiniAQLQ, followed by a 2-h rest period before completing the other version. Agreement between versions was measured using the intraclass correlation coefficient (ICC) and Bland-Altman analysis. RESULTS: Two participants with incomplete p-MiniAQLQ responses were excluded. Forty participants (85% female; age 47.7 +/- 14.9 years; asthma duration 22.6 +/- 16.1 years; FEV(1) 87.1 +/- 21.6% predicted) with both AQLQ scores <6.0 completed the study. Agreement between e- and p-versions for the overall score was acceptable (ICC=0.95) with no bias (difference (Delta) p-e=0.1; P=0.21). ICCs for the symptom, activity limitation, emotional function and environmental stimuli domains were 0.94, 0.89, 0.90, and 0.91 respectively. A small but significant bias (Delta=0.3; P=0.004) was noted in the activity limitation domain. Completion time was significantly longer for the e-version (3.8 +/- 1.9min versus 2.7 +/- 1.1min; P<0.0001). The majority of patients (57.5%) preferred the e-MiniAQLQ; 35% had no preference. CONCLUSION: This e-version of the MiniAQLQ is valid and was preferred by most participants despite taking slightly longer to complete. Generalizabilty may be limited in younger (12-17) and older (>65) adults.

Development and validation of an electronic version of the Rhinoconjunctivitis Quality of Life Questionnaire.

BACKGROUND: As clinicians and pharmaceutical companies move from paper versions of health status questionnaires to electronic versions, it cannot be assumed that adaptations to other media will produce valid data. AIMS: The aims of this study were to (1) adapt the Rhinoconjunctivitis Quality of Life Questionnaire [RQLQ(S); standardized version], for the Palm Treo 650, (2) test the device for ease and accuracy of understanding and (3) examine the validity of the electronic version by comparing it with the original paper version of the RQLQ(S). METHODS: Seventy adults with current rhinoconjunctivitis symptoms completed the electronic and paper versions of the RQLQ(S). They were randomized to complete either the paper or the electronic version first. After a 2-h break, they completed the other version. RESULTS: Concordance between paper and electronic versions for the overall RQLQ(S) score was acceptable with an intraclass correlation coefficient of 0.95 and there was no evidence of bias (P = 0.13). Concordance for the seven individual domains ranged from 0.86 to 0.94. A small but significant bias was observed in the activity and sleep domains (P = 0.02). Completion times were quicker with paper (4.1 vs 4.9 min, P < 0.0001). About 51% of patients preferred electronic, 17% preferred paper and 31% had no preference. CONCLUSIONS: This electronic version of the RQLQ(S) was easy for patients to use and the concordance between paper and this version on the Palm Treo 650 provides evidence of the validity of this electronic version.

Internet and written respiratory questionnaires yield equivalent results for adolescents.

This study compared results from Internet and written questionnaires about respiratory symptoms in order to find out if both forms of the survey yielded the same answers. One thousand seventy-one students, ages 13 to 17, were asked to complete either an Internet or a written questionnaire. The demographic characteristics of the participants equalled those of the general Dutch adolescent population. Participants were randomly assigned to fill out an electronic or written questionnaire. In addition to eight items from the International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire, two items on doctor visits (medical attention) regarding asthma or allergic disease during the past 12 months were included. The participation rate was 87%. The Internet version of the questionnaire showed fewer missing answers than the written version, but this was not statistically significant. The respiratory items did not show statistically significant score differences between the Internet and written modes of administration, and there was no visible trend for higher respectively lower scores by either mode of questionnaire administration. From these results, we conclude that respiratory questionnaires may be provided to adolescents electronically rather than on paper, since both approaches yielded equal results. To generalize these findings, we recommend repeated studies in other settings.

Responsiveness, longitudinal- and cross-sectional construct validity of the Pediatric Asthma Quality of Life Questionnaire (PAQLQ) in Dutch children with asthma.

OBJECTIVE: Health-related quality of life is an important measure in evaluations of the management of childhood asthma. In this study, we assessed psychometric properties, responsiveness, and longitudinal and cross-sectional construct validity of the Dutch version of the 23-item Pediatric Asthma Quality of Life Questionnaire (PAQLQ). METHODS: The study group consisted of 238 6-18-year olds with asthma, with complete respiratory symptom diaries in the course of one winter season; each child had one (or more) PAQLQ measurement(s) concerning one (or more) week(s) with relatively many symptoms (n = 238). Each child also had one PAQLQ measurement concerning another week with relatively few symptoms (n = 238). The PAQLQ scores of the 238 children for a week with few symptoms (the symptom diary scores remained below a predefined level everyday) were compared with their PAQLQ scores for another week with many symptoms (on day 1 of that week, symptom diary scores had been above the predefined level). Additionally, in a subgroup of the study group that had experienced two or more 'weeks with many symptoms' (n = 101), we compared the PAQLQ-scores for two different weeks with many symptoms of these children. RESULTS: Only the domain Emotions showed a ceiling effect (>25% had the maximum score). All Cronbach's alpha's of the PAQLQ total score and domains were >0.70, except for Activities (alpha = 0.54). Mean PAQLQ-scores were significantly different (p < 0.01; n = 238) between one week with few symptoms and another week with many symptoms. Contrary, in the subgroup of children with PAQLQ-measurements regarding more than one week with many symptoms (n = 101), mean PAQLQ-scores did not differ significantly (p > or = 0.05) between 1 week with many symptoms and another week with many symptoms. These results indicate responsiveness. (Changes in) lower respiratory tract symptoms, indicative of asthma severity, correlated better with (changes in) PAQLQ scores than (changes in) upper respiratory tract symptoms, which supports the longitudinal and cross-sectional construct validity. CONCLUSION: The assessed properties of the PAQLQ linguistic validation into Dutch were similar to those originally established for the PAQLQ in Canada. This study showed that the Dutch PAQLQ has adequate psychometric properties, excellent responsiveness, and that the longitudinal and cross-sectional construct validity is supported.

Relationship between quality of life and clinical status in asthma: a factor analysis.

Many studies have shown that correlation between clinical asthma status and asthma-specific quality of life is only weak to moderate. However, this relationship has never been explored to determine whether the weakness is due to noise of measurement or whether quality of life is a distinct component of asthma health status. With a database from three clinical trials (n = 763), factor analysis was used to explore the relationships between quality of life, measured by the Asthma Quality of Life Questionnaire (AQLQ), and conventional measures of asthma clinical status (symptoms, airway calibre and rescue beta2-agonist use). The analysis revealed that although patients with severe, poorly controlled asthma tend to have worse quality of life than milder, well-controlled patients, overall asthma health status has four components (factors): asthma-specific quality of life; airway calibre; daytime symptoms and daytime beta2-agonist use, and night-time symptoms and night-time beta2-agonist use. The clean loading of all 21 outcomes onto four distinct and clinically identifiable factors suggests that, although some weakness of correlation between clinical indices and quality of life may be due to noise of measurement, it is mainly attributable to asthma health status being composed of distinct components.

Health-related quality of life in asthma studies. Can we combine data from different countries?

The aim was to compare health-related quality of life (HRQL) in patients with asthma from 4 countries, and to investigate the correlations between HRQL and clinical indices.341 patients; 140 (Sweden), 54 (Norway), 65 (the Netherlands) and 82 (Greece) were treated with formoterol fumarate 4.5 microg or with terbutaline sulphate 0.5mg for 12 weeks inhaled 'on demand' via Turbuhaler. The Asthma Quality of Life Questionnaire (AQLQ) and clinical indices were assessed. The mean baseline AQLQ overall scores in Sweden (4.97), in the Netherlands (5.04), in Norway (4.68) and in Greece (4.68) were in the same range, however, with a significant difference between the four countries (p=0.038). When comparing AQLQ, activity limitation and symptoms domains, the differences between the countries were not statistically significant. The cross-sectional correlations between AQLQ overall score and the clinical indices were similar in all four countries. The magnitude of change in AQLQ was consistent with the other clinical variables. The correlations between change in AQLQ overall score and change in clinical indices were low to medium in all countries. In conclusion, the consistency of cross-sectional correlations between the AQLQ overall and clinical indices across countries supports the validity of translations of the AQLQ used in this study. There were differences in baseline values between the countries. The treatment response in AQLQ differed to the same extent as other clinical indices. When combining HRQL data from different countries, there might be cultural, gender and socio-economic differences, explaining different responses to treatment.

Can the standard gamble and rating scale be used to measure quality of life in rhinoconjunctivitis? Comparison with the RQLQ and SF-36.

BACKGROUND: With interest in health economics growing, it is important to know whether utilities may be used to measure health-related quality of life in patients with rhinoconjunctivitis. The objective was to compare the validity and measurement properties of disease-specific versions of the standard gamble and rating scale with those of the Rhinoconjunctivitis Quality of Life Questionnaire (RQLQ) and the Short-Form 36 (SF-36). METHODS: One hundred adults with symptomatic rhinoconjunctivitis participated in a 5 week observational study, completing the standard gamble, rating scale, RQLQ and SF-36 at baseline and after 1 and 5 weeks. Symptom diaries were completed for 1 week before each follow-up visit. RESULTS: Reliability was highest for the RQLQ (intraclass correlation coefficient = 0.97), followed by the rating scale (0.75), the SF-36 physical (0.75), the SF-36 mental (0.74) and the standard gamble (0.12). The responsiveness index was highest for the RQLQ (0.76), followed by the rating scale (0.56) and the SF-36 mental (0.28). Both cross-sectional and longitudinal validity were strongest for the RQLQ and the rating scale. CONCLUSIONS: Both the rating scale and the RQLQ have strong evaluative and discriminative properties. The SF-36 has acceptable discriminative properties but its evaluative properties are poor. All measurement properties for the standard gamble are inadequate. Poor correlation between the standard gamble and the rating scale indicates that utilities cannot be derived from rating scale data.

Using humanistic health outcomes data in asthma.

One of the aims of treatment of asthma is to improve patient well-being, which incorporates the concept of patients' perceptions of how they feel and their ability to function in their everyday life [health-related quality of life (HR-QOL)]. The weak association between conventional measures of clinical status in asthma and asthma-specific quality of life means that quality of life must be measured directly--it cannot be inferred from clinical measures. HR-QOL is measured using instruments which elicit information from patients about the impact of the disease and its treatment on both their physical and emotional functioning. Such instruments may be generic (used for all diseases) or specific to a particular group of patients, function or disease. Disease-specific quality-of-life questionnaires are useful in clinical trials and practice because they are more responsive to small but clinically important changes than generic instruments. Generic instruments provide an estimate of the patients' burden of illness that can be compared with the burden experienced by patients with other medical conditions. Consequently, HR-QOL should be included as an outcome measure in all assessments of asthma.

Comparison of the standard gamble, rating scale, AQLQ and SF-36 for measuring quality of life in asthma.

With interest in health economics growing, there is a demand for valid methods for measuring health-related quality of life (HRQL) in asthma using utilities. The aims of this study were to develop disease-specific versions of the standard gamble and rating scale, to compare their measurement properties with those of the Asthma Quality of Life Questionnaire (AQLQ) and the Medical Outcomes Survey Short-Form 36 (SF-36), as well as to determine their validity for assessing asthma-specific quality of life. Forty adults with symptomatic asthma participated in a 9-week observational study. Participants completed the standard gamble, rating scale, AQLQ, SF-36 and other measures of clinical asthma status at baseline and after 1, 5 and 9 weeks. In patients whose asthma was stable between assessments, reliability was good for the rating scale (intraclass correlation coefficient (ICC)=0.89) and the AQLQ (ICC=0.95) but more modest for the SF-36 mental score (ICC=0.68), SF-36 physical score (ICC=0.65) and standard gamble (ICC=0.59). The responsiveness index was highest in the AQLQ (1.35), followed by the rating scale (0.74), the physical score of the SF-36 (0.61) and the standard gamble (0.31). Construct validity (correlation with other indices of health status) was strongest for the AQLQ and the rating scale. In conclusion, both the disease-specific rating scale and the Asthma Quality of Life Questionnaire have strong measurement properties for measuring asthma-specific quality of life; the Short-Form 36 health survey physical summary score has more modest properties. Although the disease-specific standard gamble has acceptable discriminative properties, its evaluative properties are too inadequate for it to be used in cost/utility analyses. Poor correlation between the standard gamble and the rating scale indicates that utilities cannot be derived from rating scale data.

Measuring asthma control in group studies: do we need airway calibre and rescue beta2-agonist use?

Collection of airway calibre and beta2-agonist data in large clinical trials and epidemiological surveys is sometimes difficult and may be an inefficient use of resources. The aim of this study was to determine whether the omission of the forced expiratory volume in 1 sec (FEV1) and beta2-agonist questions from the seven-item Asthma Control Questionnaire (ACQ) alters its measurement properties and validity. In an observational study, 50 adults with symptomatic asthma attended the clinic at 0, 1, 5 and 9 weeks to complete the ACQ and other measures of asthma status. All patients completed the study and provided complete data sets. Omission of the FEV1 and beta2-agonist questions from the ACQ made minimal difference to the reliability, responsiveness, and both cross-sectional and longitudinal validity of the instrument. Omission of the FEV1 question significantly lowered the summary score (P<0.001) but omission of the beta2-agonist question did not alter it (P>0.05). In group studies, both the FEV1 and beta2-agonist questions may be omitted from the ACQ without changing the validity or the measurement properties of the instrument. Lowering of the summary score by the omission of the FEV1 question means that data from this abbreviated form cannot be combined with or compared to data collected using the full questionnaire.

Olopatadine ophthalmic solution adjunctive to loratadine compared with loratadine alone in patients with active seasonal allergic conjunctivitis symptoms.

BACKGROUND: Olopatadine ophthalmic solution 0.1% (Patanol, Alcon Laboratories, Fort Woth, TX) is approved for the treatment of the signs and symptoms of allergic conjunctivitis. Loratadine 10 mg (Claritin, Schering-Plough, Madison, NJ) is a nonsedating oral antihistamine approved for the treatment of the signs and symptoms of allergic rhinitis. OBJECTIVE: To compare the efficacy of olopatadine used adjunctively with loratadine versus loratadine alone in patients with seasonal allergic conjunctivitis. METHODS: This three-center, observer-masked, treatment-controlled, randomized, parallel-group study involved patients aged 7 to 74 years with seasonal allergic conjunctivitis. Patients were treated for 7 days with either olopatadine twice daily adjunctive to loratadine once daily or only loratadine once daily. Efficacy variables (ocular itching and redness, physician's impression, patient's impression, patient diary ratings of ocular redness and itching), and safety parameters were evaluated during the screening visit and on days 0, 3, and 7. Patients completed the rhinoconjunctivitis quality of life questionnaire on days 0 and 7. RESULTS: Ninety-four patients received study drug. Patients receiving olopatadine twice daily in addition to loratadine once daily exhibited less ocular itching (P = 0.0436) and rated their ocular condition as more improved compared with those receiving loratadine alone (P < 0.0022). Twenty minutes after initial dosing, olopatadine plus loratadine relieved ocular itching and redness significantly better than loratadine alone (P = 0.001). Both treatment groups showed clinically meaningful improvements in overall quality of life in all but one of the rhinoconjunctivitis quality of life questionnaire domains. Overall, and in most domains, olopatadine plus loratadine also provided significantly better (P < 0.05) quality of life than loratadine alone at day 7. CONCLUSIONS: Compared with loratadine alone, olopatadine adjunctive to loratadine provides greater relief of ocular itching and redness, a better quality of life, and is well tolerated in patients with seasonal allergic conjunctivitis.

Clinical predictors of health-related quality of life depend on asthma severity.

The National Asthma Education and Prevention Program guidelines define asthma severity before treatment by lung function and symptoms. It has been assumed, but not demonstrated, that improvement in these measures would translate into improvement in health-related quality of life (HRQL). Because HRQL is an important outcome in asthma management, we asked what are the determinants of HRQL? To address this question, we retrospectively analyzed HRQL data, as measured by the Juniper Asthma Quality of Life Questionnaire, in subjects with mild versus moderate-severe asthma from two clinical trials. We examined whether these traditional clinical outcomes have different relationships to HRQL depending on asthma severity. We also assessed whether the relationship between clinical outcomes and HRQL in subjects with moderate-severe asthma would change when subjects improved to mild-moderate disease with controller medication treatment. Lung function was not an independent predictor or determinant of HRQL at any level of asthma severity, whereas intensity of shortness of breath predicted HRQL at all levels of asthma severity. Rescue beta-agonist use independently predicted HRQL in subjects with mild asthma, but not in those with moderate-severe asthma. In subjects with moderate-severe asthma who improved to mild-moderate disease with controller treatment, rescue beta-agonist use predicted HRQL. We conclude that the independent determinants of HRQL vary according to asthma severity and change with asthma treatment.

Does electronic implementation of questionnaires used in asthma alter responses compared to paper implementation?

BACKGROUND: Electronic implementation of questionnaires has many advantages, but there may be concerns that it alters versions that were validated on paper. OBJECTIVE: To determine whether electronic implementation alters responses to the SF-36 and asthma quality of life questionnaire (AQLQ), compared to paper implementation. METHODS: Patients with asthma presenting to a pneumologist were asked for consent to participate. Each patient completed both forms of each questionnaire. The order of presentation was alternated sequentially, with the first patient completing the electronic version first. Each patient waited at least 2 hours between completions to minimize recollection of answers. For both the SF-36 and AQLQ, intraclass correlations coefficients were calculated to compare patients' scores, for each scale and overall, on the electronic and paper versions. RESULTS: Sixty-eight patients (mean age: 48 years, 50 females) of 311 contacted were enrolled. Overall intraclass correlation coefficients for the SF-36 and AQLQ were excellent (0.965 and 0.991 respectively). For paper versions, eight questions (AQLQ) and 24 (SF-36) were left blank and nine questions (SF-36) were answered incorrectly by patients selecting more than one answer. Electronic data for one patient could not be retrieved. CONCLUSION: Collecting SF-36 and AQLQ data electronically can decrease the number of spoiled responses without altering the results. Successful implementation depends on proper instruction of the respondent in the handling of the electronic instrument.

Quality of life in patients with allergic rhinitis.

LEARNING OBJECTIVES: Reading this article will familiarize the practitioner with ongoing efforts to measure the effects of allergic rhinitis symptoms and its treatments on the health-related quality of life (HRQOL) of patients. The reader will learn about instruments used to collect HRQOL data, results of studies showing the burden of illness and the effects of treatments on HRQOL, and efforts to interpret the clinical relevance of changes in HRQOL status. DATA SOURCES: Information was gleaned from articles listed in MEDLINE regarding HRQOL in allergic rhinitis between 1966 and 2000 (English language only), and from the personal experiences of the authors. STUDY SELECTION: Questionnaire validation studies and representative controlled trials employing measures to assess the effects of allergic rhinitis symptoms and its treatments on HRQOL are described. RESULTS FROM THIS REVIEW: Allergic rhinitis symptoms can have detrimental effects on the physical, psychologic, and social aspects of patients' lives. Clinical trial data suggest a variety of pharmacologic therapies can significantly improve HRQOL in patients with allergic rhinitis. Validated questionnaires are now available that can easily be used in clinical practice to measure the effects of interventions on HRQOL for individual patients. CONCLUSIONS: Evaluating the effects of interventions on HRQOL may be particularly important in a non-life-threatening condition such as rhinitis. Health-related quality of life measures can be used to indicate the risk/benefit and the cost/benefit ratios of competing treatment options. Clinicians and policy makers are already using HRQOL data to evaluate results of medical interventions to guide patient management and reimbursement decisions.

Measuring asthma control. Clinic questionnaire or daily diary?

Daily symptom, peak expiratory flow rate (PEFR), and medication diaries are often used in clinical trials of treatments for asthma on the assumption that they provide a better estimate of clinical status than does a questionnaire completed in the clinic. We conducted a study with the aim of comparing the measurement properties of the clinic-completed Asthma Control Questionnaire with those of the Asthma Control Diary. The diary is composed of questions and response options almost identical to those of the questionnaire, but uses PEFR instead of FEV(1) as the measure of airway caliber. In an observational study, 50 adults with symptomatic asthma attended a McMaster University asthma clinic at 0, 1, 5, and 9 wk to complete the Asthma Control Questionnaire and other measures of asthma status. For 1 wk before each follow-up visit, patients completed the Asthma Control Diary every morning and evening. Concordance between the questionnaire and diary was high (intraclass correlation coefficient [ICC] = 0.87). Both reliability (ICC: questionnaire = 0.90; diary = 0.86) and responsiveness (responsiveness index: questionnaire = 1.06; diary = 0.90; p = 0.005) were better with the questionnaire than with the diary. Correlations between the two instruments and other measures of clinical asthma status were similar and close to a priori predictions. Both the Asthma Control Questionnaire and the Asthma Control Diary are valid instruments for measuring asthma control, but the questionnaire has slightly better discriminative and evaluative measurement properties than does the diary.