Prediction of the severity of allergic reactions to foods.

BACKGROUND: There is currently considerable uncertainty regarding what the predictors of the severity of diagnostic or accidental food allergic reactions are, and to what extent the severity of such reactions can be predicted. OBJECTIVE: To identify predictors for the severity of diagnostic and accidental food allergic reactions and to quantify their impact. METHODS: The study population consisted of children with a double-blind, placebo-controlled food challenge (DBPCFC)-confirmed food allergy to milk, egg, peanut, cashew nut, and/or hazelnut. The data were analyzed using multiple linear regression analysis. Missing values were imputed using multiple imputation techniques. Two scoring systems were used to determine the severity of the reactions. RESULTS: A total of 734 children were included. Independent predictors for the severity of the DBPCFC reaction were age (B = 0.04, P = .001), skin prick test ratio (B = 0.30, P < .001), eliciting dose (B = -0.09, P < .001), level of specific immunoglobulin E (B = 0.15, P < .001), reaction time during the DBPCFC (B = -0.01, P = .004), and severity of accidental reaction (B = 0.08, P = .015). The total explained variance of this model was 23.5%, and the eliciting dose only contributed 4.4% to the model. Independent predictors for more severe accidental reactions with an explained variance of 7.3% were age (B = 0.03, P = .014), milk as causative food (B = 0.77, P < .001), cashew as causative food (B = 0.54, P < .001), history of atopic dermatitis (B = -0.47, P = .006), and severity of DBPCFC reaction (B = 0.12, P = .003). CONCLUSIONS: The severity of DBPCFCs and accidental reactions to food remains largely unpredictable. Clinicians should not use the eliciting dose obtained from a graded food challenge for the purposes of making risk-related management decisions.

Incomplete and incorrect epinephrine auto-injector training to food-allergic patients by pharmacists in the Netherlands.

BACKGROUND: Successful treatment of anaphylaxis in the community relies on early and correct use of epinephrine auto-injectors (EAI). In the Netherlands, pharmacists supply EAIs to patients and have a crucial role in instructing patients in how and when to use EAI. However, there are currently no data in Europe on the quality of such instruction provided by pharmacists. Therefore, the aims of this study were to investigate the knowledge, attitudes, and beliefs regarding food allergy among pharmacists in the Netherlands and to investigate the quality of EAI instructions and demonstrations to patients by pharmacists. METHODS: Pharmacists were asked to complete an online questionnaire. Quality of instructions and demonstration accuracy were assessed in mystery guest visits to randomly selected pharmacies. For the statistical analysis, descriptive methods were used. RESULTS: In total, 25 of 115 questionnaires were completed. Only two (8%) respondents gave correct answers concerning the proper EAI demonstration. Twenty-one (84%) respondents thought that the provision of instructions was the responsibility of pharmacists. In total, ten pharmacies were included in simulated patient visits. Five of them (50%) demonstrated the EAI. None of them demonstrated the EAI use correctly. CONCLUSION: Food-allergic patients at high risk for anaphylaxis who receive their EAI from a community pharmacy are often not instructed on how to use an EAI or receive incorrect instructions. Pharmacists show considerable gaps in knowledge about food allergy and its management. These data suggest that opportunities exist to improve the quality of care provided by pharmacies to high-risk food-allergic patients.

Late reactions in food-allergic children and adolescents after double-blind, placebo-controlled food challenges.

The time during which children are observed following a double-blind, placebo-controlled food challenge (DBPCFC) varies in clinical practice. There are little data on late reactions (LRs) following DBPCFCs. Therefore, we determined the prevalence, severity and clinical characteristics of late reactions in food-allergic children and adolescents after DBPCFC, and ascertained which factors are associated with, and may predict, LRs. Logistic regression analyses were performed to investigate which factors were associated with LRs and to develop the association and prediction models. A total of 1142 children underwent DBPCFCs (child-test combinations). Of these 1142 child-test combinations, 400 reported LRs following the DBPCFC. LRs in food-allergic children after DBPCFC are poorly predictable and are generally not severe. All LRs, including those on the placebo day, are more frequently reported in younger children. Children who do not experience severe immediate reactions may be safely discharged home 2 h after a DBPCFC.

Patient-reported disease-specific quality-of-life and symptom severity in systemic mastocytosis.

BACKGROUND: Presently, no validated data exist on symptom severity and disease-specific quality-of-life (QoL) for patients with mastocytosis. Simultaneously, clinical trials and drug application processes increasingly mandate reporting patients' perspectives on symptoms and QoL. We report on the development and validation of the mastocytosis quality-of-life questionnaire (MQLQ) and the mastocytosis symptom assessment form (MSAF). METHODS: Both outcome measures were developed in a standardized stepwise method, starting with the identification of items in focus groups (n = 12), item reduction and subsequent cross-sectional validation in a 63% female cohort of 164 adult patients with indolent systemic mastocytosis. RESULTS: The MSAF reveals that fatigue is the severest mastocytosis symptom while the MQLQ indicates that fear of anaphylaxis mostly impacts QoL. Cross-sectional validity was assessed by correlating both individual domains and the total scores of the MQLQ and MSAF with independent measures of mastocytosis. The total scores of both the MQLQ (P < 0.001; Spearman's r: 0.568) and the MSAF (P < 0.001; Spearman's r: 0.559) correlated significantly with the consensus on physician-scored mediator symptoms. The MQLQ domains displayed a high internal consistency (Cronbach's alpha: 0.841-0.958) and the domains 'bones', 'skin symptoms' and 'anaphylaxis' differed significantly between patients with and without osteoporosis, urticaria pigmentosa or anaphylaxis, respectively (P < 0.001). CONCLUSIONS: The MQLQ is the first disease-specific QoL questionnaire for mastocytosis and is complemented by the MSAF, a short and convenient symptom scoring form. Both patient-reported outcome measures are valid, reliable and discriminate between patients with different disease characteristics, making them useful instruments for clinical research.

The compliance and burden of treatment with the epinephrine auto-injector in food-allergic adolescents.

BACKGROUND: Food-allergic patients at high risk of potential fatal anaphylaxis should carry an epinephrine auto-injector (EAI) at all times. This treatment may be perceived as burdensome and this may affect compliance and health-related quality of life (HRQL). The aims of the study were (1) to determine the burden of treatment (BoT) of an EAI, (2) to examine the relationship between this burden and compliance, and (3) to analyze which factors contribute to the BoT of the EAI as perceived by food-allergic adolescents and their parents. METHODS: Dutch food-allergic adolescents prescribed an EAI, and their parents completed a questionnaire package (n = 55). Relationships between BoT and HRQL, illness severity and perception, and anxiety measures were investigated. RESULTS: Food-allergic adolescents and their parents were (extremely) positive about the EAI (54.5%; 72.7%, respectively) (=low BoT). The BoT measure showed a significantly greater burden in food-allergic adolescents prescribed an EAI who reported not carrying the EAI at all times than adolescents who reported they did. The BoT scores of both adolescents and their parents were not associated with HRQL, illness severity and perception, or trait anxiety. CONCLUSIONS: The majority of food-allergic adolescents and their parents were positive about the EAI (=low BoT). However, the BoT was significantly associated with self-reported compliance with carrying the EAI. The BoT was higher in food-allergic adolescents prescribed an EAI who reported not carrying the EAI at all times. The BoT measure seems to be a useful tool to study compliance with carrying an EAI. The BoT of an EAI is not associated with HRQL. The BoT measures a distinct concept related to compliance behavior.

No difference in health-related quality of life, after a food challenge with cashew nut in children participating in a clinical trial.

BACKGROUND: Previous studies showed that health-related quality of life (HRQL) significantly improved after the food challenge, with greater improvements in HRQL after a negative outcome than after a positive outcome. It is currently unknown whether this also occurs in patients undergoing DBPCFCs with cashew nut in the context of a clinical trial. METHODS: Quality of life was studied in children enrolled in a cashew nut study using Food Allergy Quality of Life Questionnaires (FAQLQs). Children, teenagers and parents of the children completed the questionnaires before the challenge test and 6 months after the DBPCFC with cashew nut. The difference in the change in HRQL between the children with a positive and negative DBPCFC outcome was studied by Mann-Whitney U-test. RESULTS: In total, 112 children (67 boys, median age of 9 years) were included. The children, teenagers and parents of the children completed 143 sets of questionnaires in total. There were no significant differences in baseline total and domain scores compared to the follow-up scores in the FAQLQ-CF, FAQLQ-TF and FAQLQ-PF. In children, the delta FAIM score in the negative DBPCFC tested group was significantly better than the delta FAIM score in the positive challenged group (p = 0.026). There were no significant differences in the changes in the scores of the FAQLQ-CF and FAQLQ-PF in the children with a positive challenge outcome, compared to the children with a negative challenge result. However, there was a significant difference in the change in score between the latter groups in the domain 'accidental exposure' of the FAQLQ-TF (p = 0.049). CONCLUSION: This study showed no difference in the change in HRQL scores after a DBPCFC with cashew nut in children participating in a clinical trial. The utility of HRQL as an outcome for clinical trials in food allergy may be limited if participant baseline HRQL is relatively unimpaired.

Loss-of-function variants of the filaggrin gene are associated with clinical reactivity to foods.

The aim of this study was to assess the genetic association of Filaggrin loss-of-function (FLG LOF) genetic variants with food allergy, and to investigate the added value of this test in diagnosing food allergy. Clinical reactivity to foods was diagnosed by the gold standard, the double-blind, placebo-controlled food challenge. Of 155 children, 33 (21.3%) children had at least one FLG LOF variant, and of these, 29 (87.9%) were clinically reactive to at least one food, compared to 73 of 122 children (59.8%) carrying wild-type alleles. The odds ratio for having at least one FLG LOF variant and clinical reactivity to at least one food was 4.9 (CI = 1.6-14.7, P = 0.005), corresponding to a relative risk of 1.5, compared to carriers of wild-type alleles. Prediction of food allergy improved when FLG LOF variants were included in the model. Therefore, genetic markers may be useful as an addition to clinical assessment in the diagnosis of food allergy.

Predictors of health-related quality of life of European food-allergic patients.

BACKGROUND: Although food allergy has universally been found to impair HRQL, studies have found significant differences in HRQL between countries, even when corrected for differences in perceived disease severity. However, little is known about factors other than disease severity which may contribute to HRQL in food-allergic patients. Therefore, the aim of this study was to identify factors which may predict HRQL of food-allergic patients and also to investigate the specific impact of having experienced anaphylaxis and being prescribed an EAI on HRQL. METHODS: A total of 648 European food-allergic patients (404 adults, 244 children) completed an age-specific questionnaire package including descriptive questions. Multivariable regression analyses were performed to develop models for predicting HRQL of these patients. RESULTS: For adults, the prediction model accounted for 62% of the variance in HRQL and included perceived disease severity, type of symptoms, having a fish or milk allergy, and gender. For children, the prediction model accounted for 28% of the variance in HRQL and included perceived disease severity, having a peanut or soy allergy, and country of origin. For both adults and children, neither experiencing anaphylaxis nor being prescribed an epinephrine auto-injector (EAI) contributed to impairment of HRQL. CONCLUSIONS: In this study, food allergy-related HRQL may be predicted to a greater extent in adults than in children. Allergy to certain foods may cause greater HRQL impairment than others. Country of origin may affect HRQL, at least in children. Experiencing anaphylaxis or being prescribed an EAI has no impact on HRQL in either adults or children.

EAACI Food Allergy and Anaphylaxis Guidelines. Food allergy health-related quality of life measures.

Instruments have been developed and validated for the measurement of health-related quality of life in patients with food allergy. This guideline has been prepared by the European Academy of Allergy and Clinical Immunology's (EAACI) Guidelines for Food Allergy and Anaphylaxis Group. It draws on a systematic review of the literature on quality of life instruments for food allergy and the Appraisal of Guidelines for Research & Evaluation (AGREE II) guideline development process. Guidance is provided on the use of such instruments in research, and the current limitations of their use in clinical practice are described. Gaps in current knowledge as well as areas of future interest are also discussed. This document is relevant to healthcare workers dealing with food-allergic patients, scientists engaging in food allergy research and policy makers involved in regulatory aspects concerning food allergy and safety.

Disease-specific health-related quality of life instruments for IgE-mediated food allergy.

This is one of seven interlinked systematic reviews undertaken on behalf of the European Academy of Allergy and Clinical Immunology as part of their Guidelines for Food Allergy and Anaphylaxis, which focuses on instruments developed for IgE-mediated food allergy. Disease-specific questionnaires are significantly more sensitive than generic ones in measuring the response to interventions or future treatments, as well as estimating the general burden of food allergy. The aim of this systematic review was therefore to identify which disease-specific, validated instruments can be employed to enable assessment of the impact of, and investigations and interventions for, IgE-mediated food allergy on health-related quality of life (HRQL). Using a sensitive search strategy, we searched seven electronic bibliographic databases to identify disease-specific quality of life (QOL) tools relating to IgE-mediated food allergy. From the 17 eligible studies, we identified seven disease-specific HRQL instruments, which were then subjected to detailed quality appraisal. This revealed that these instruments have undergone formal development and validation processes, and have robust psychometric properties, and therefore provide a robust means of establishing the impact of food allergy on QOL. Suitable instruments are now available for use in children, adolescents, parents/caregivers, and adults. Further work must continue to develop a clinical minimal important difference for food allergy and for making these instruments available in a wider range of European languages.

No matrix effect in double-blind, placebo-controlled egg challenges in egg allergic children.

BACKGROUND: Diagnostic and accidental food allergic reactions may be modified by the matrix containing the allergenic food. Previous studies of double-blind, placebo-controlled food challenges (DBPCFCs) with peanut found an effect of the fat content of the challenge matrix on the severity of the challenge reactions. OBJECTIVE: The aim of this study was to examine whether the fat content of the food matrix is related to eliciting dose and reaction severity in DBPCFCs with heated hen's egg. METHODS: Sensitized egg allergic children (n = 59) undergoing DBPCFCs with egg as a routine diagnostic procedure in our tertiary care centre were evaluated retrospectively. Three different recipes were used for the food matrix: vanilla pudding, pancake and minced meat, containing 22.8%, 31.9% and 52.7% fat (weighted average), respectively. The eliciting dose (i.e. the highest cumulative dose to which the child reacted) was analyzed by Kaplan-Meier log-rank statistic and by Cox regression. Reaction severity was quantified by using an index (range 1-12) and was analysed by multiple linear regression analysis. RESULTS: The overall influence of type of recipe on eliciting dose was not significant (P = 0.12). The rate of response to minced meat (with the highest fat content) was not significantly different from pudding [HR = 0.61 (0.26-1.45, P = 0.26) or pancake (HR = 1.41 (0.50-3.99), P = 0.52] after adjustment for confounders. The type of recipe did not influence the severity of the challenge reaction. The severity of the challenge reaction for minced meat compared to pudding and pancake was 1.06 (0.52-2.16), P = 0.87 and 0.81 (0.32-2.01), P = 0.64, respectively, after correction for confounders. CONCLUSION AND CLINICAL RELEVANCE: In contrast to similar research with peanut, no significant influence of the fat content of the matrix was found on the eliciting dose or severity of the reaction in 59 DBPCFCs with hen's egg. Matrix fat content differences comparable to those reported here may not be an important co-determinant of reaction severity for all allergenic foods.

Quality of life measures for food allergy.

Food allergy has become an emerging health problem in Western societies. Although food allergy is characterized by a relatively low mortality and an almost continual absence of physical symptoms, food allergic patients are continually confronted with the possibility of potentially severe reactions and the necessity of dietary vigilance. Health-related quality of life (HRQL) may be the only meaningful outcome measure available for food allergy measuring this continuous burden. HRQL may be measured with generic or disease-specific instruments. Generic instruments may be relatively unresponsive to differences or changes in health status, whereas disease-specific instruments are generally more sensitive for relatively subtle problems related to a particular illness. Recently, a number of disease-specific questionnaires have become available to measure the HRQL of food allergic patients. An important area for further research is the interpretation of the outcome of HRQL measures. In this respect, the minimal clinically important difference (MCID) is of special interest. In combination with the numbers needed to treat (NNT), this may give an ultimate insight into the clinical relevance of an intervention. Since there is still no cure for food allergy, the only available treatment is strict avoidance of the culprit food and provision of emergency treatment. The double-blind placebo-controlled food challenge (DBPCFC) is considered to be the gold standard for diagnosing food allergy. A number of studies have investigated the perceptions of parents whose children underwent a DBPCFC. In contrast to the parental perception, there is much currently still unknown about the effects of undergoing a DBPCFC in the perceptions of patients. In addition to the research on MCID and NNT of food allergy HRQL questionnaires, further research should focus on deriving quality-adjusted life years (QALYs) from food allergy HRQL questionnaires and the application of food allergy HRQL questionnaires at the individual patient level in clinical practice.

Online version of the food allergy quality of life questionnaire-adult form: validity, feasibility and cross-cultural comparison.

BACKGROUND: Food-allergic reactions occur in 3-4% of the adult population in Western countries. It has been shown that food allergy may impair health-related quality of life (HRQL). Food allergy quality of life questionnaires (FAQLQs) have been developed and validated, including an adult form (FAQLQ-AF). These questionnaires may be particularly useful for cross-cultural comparisons. OBJECTIVES: The aims of this study were to translate the FAQLQ-AF from Dutch into English and validate an online version in the United States. Additionally, HRQL of American and Dutch food-allergic adults was compared. METHODS: The Dutch FAQLQ-AF was translated into English as set out by the World Health Organization and converted to an electronic online format. Participants (food allergic American adults) were recruited through the 'Food Allergy and Anaphylaxis Network' website and completed the questionnaire online. Construct validity, internal consistency, discriminative ability and feasibility were analysed. A cross-cultural comparison was made using the Dutch FAQLQ-AF scores. RESULTS: Data from 180 American participants were analysed. The online FAQLQ-AF had a good construct validity (correlation with FAIM: ρ=0.72; P<0.001), internal consistency (Cronbach's α=0.95) and was discriminative for 'anaphylaxis' vs. 'no anaphylaxis' and 'number of food allergies'. The most striking finding was a significantly greater impairment in HRQL in the American participants, as compared with their Dutch counterparts (the total FAQLQ-AF scores were 4.3 vs. 3.5, respectively; P<0.001, where 1 signifies no impairment and 7 signifies extreme impairment in HRQL). CONCLUSIONS AND CLINICAL RELEVANCE: The online American FAQLQ-AF is a valid instrument to measure HRQL in food-allergic patients in the United States. Additionally, HRQL of American food-allergic adults may be more impaired than Dutch food-allergic adults. The FAQLQ-AF can now be used to determine the HRQL in American food-allergic adults and can assist clinicians in optimizing management strategies for food-allergic patients.

Parents report better health-related quality of life for their food-allergic children than children themselves.

BACKGROUND: Food allergy affects 5-6% of children and impairs health-related quality of life (HRQL). Children and parents may differ in their views concerning the child's HRQL. In food allergy, child- and parent-proxy-reported HRQL have never been compared using valid disease-specific instruments. OBJECTIVE: The aim of this study was to compare child- and parent-proxy reports on HRQL in food-allergic children (8-12 years). METHODS: The Food Allergy Quality of Life Questionnaire-Child Form (FAQLQ-CF), and -Parent Form (FAQLQ-PF) and the Food Allergy Independent Measure-Child Form and -Parent Form (FAIM-CF and -PF) were completed by Dutch food-allergic child-parent pairs. Child- and parent-proxy reports were correlated and tested for significant differences. Construct validity (Spearman's correlation coefficient between the FAQLQs and FAIMs) and internal consistency (Cronbach's α) were assessed and compared. RESULTS: Seventy-four child-parent pairs were included. The FAQLQ-CF score was significantly higher than the FAQLQ-PF score (3.74 vs. 2.68, P<0.001, where 1 indicates no impairment and 7 indicates extreme impairment). FAIM-CF and -PF scores were almost identical (3.29 vs. 3.33, P=0.594). There was moderate agreement between the FAQLQ-CF and -PF scores (ICC=0.57 [P<0.001]) and good agreement between the FAIM-CF and -PF scores (ICC=0.80 [P<0.001]). Construct validity was confirmed for the FAQLQ-CF (ρ=0.60, P<0.001) and -PF (ρ=0.58, P<0.001). Internal consistency was excellent for the FAQLQ-CF (α=0.95) and -PF (α=0.95). CONCLUSIONS AND CLINICAL RELEVANCE: Parents reported significantly less impact of food allergy on the child's HRQL than children themselves, while reported perceptions of disease severity were nearly identical. This may reflect real differences in perspectives between children and parents and may indicate that parents tend to underestimate their child's HRQL impairment. It is important for clinicians to include both the child's and their parent's perceptions in order to perform a complete assessment of the impact of food allergy on the child's HRQL and to identify areas of disagreement that need special attention in clinical practice.

Adolescent-parent disagreement on health-related quality of life of food-allergic adolescents: who makes the difference?

BACKGROUND: Food-allergic adolescents are at highest risk for food allergy fatalities, which may be partly due to compromised self-management behavior. Such behavior may be negatively influenced by conflictual situations caused by adolescent-parent disagreement on the adolescent's health-related quality of life (HRQL). Comparisons of adolescent-self-reported and parent-proxy-reported HRQL of food-allergic adolescents have never extensively been studied. The aims of this study were to investigate disagreement in adolescent-self-reports and parent-proxy-reports on the HRQL of food-allergic adolescents and to investigate the factors influencing adolescent-parent disagreement. METHODS: Teenager Form (TF) and Parent Form (PFA) of the Food Allergy Quality of Life Questionnaire (FAQLQ), Food Allergy Independent Measure (FAIM), and Brief-Illness Perception Questionnaire (Brief-IPQ) were sent to food-allergic Dutch adolescents (13-17 years) and their parents. ICCs, t-tests, and Bland-Altman plots were used to investigate adolescent-parent disagreement. Participant characteristics, illness expectations, and illness perceptions influencing adolescent-parent disagreement were studied using regression analysis. RESULTS: Seventy adolescent-parent pairs were included. There were a moderate correlation (ICC = 0.61, P < 0.001) and no significant difference (3.78 vs 3.56, P = 0.103) between adolescent-self-reported and parent-proxy-reported HRQL at group level. However, Bland-Altman plots showed relevant differences (exceeding the minimal important difference) for 63% of all adolescent-parent pairs. Adolescent's age (> 15 years), poorer adolescent-reported illness comprehension (Brief-IPQ-TF, coherence), and higher adolescent-reported perceived disease severity (Food Allergy Independent Measure-Teenager Form & -Parent Form) were associated with adolescent-parent disagreement. CONCLUSIONS: Adolescent-parent disagreement on the adolescent's HRQL was mainly associated with adolescents' rather than parents' perceptions and characteristics. Illness comprehension of the adolescent may be an important target for intervention aimed at reducing adolescent-parent disagreement.

Longitudinal validity and responsiveness of the Food Allergy Quality of Life Questionnaire - Parent Form in children 0-12 years following positive and negative food challenges.

BACKGROUND: There are no published studies of longitudinal health-related quality of life (HRQL) assessments of food-allergic children using a disease-specific measure. OBJECTIVE: This study assessed the longitudinal measurement properties of the Food Allergy Quality of Life Questionnaire - Parent Form (FAQLQ-PF) in a sample of children undergoing food challenge. METHODS: Parents of children 0-12 years completed the FAQLQ-PF and the Food Allergy Independent Measure (FAIM) pre-challenge and at 2 and 6 months post food challenge. In order to evaluate longitudinal validity, differences between Group A (positive challenge) and Group B (negative challenge) were expected over time. We computed correlation coefficients between change scores in the FAQLQ-PF and change scores in the FAIM. To determine the minimally important difference (MID), we used distributional criterion and effect size approaches. A logistic regression model profiled those children falling below this point. RESULTS: Eighty-two children underwent a challenge (42 positive; 40 negative). Domains and total score improved significantly at pos-challenge time-points for both groups (all P<0.05). Sensitivity was demonstrated by significant differences between positive and negative groups at 6 months [F(2, 59)=6.221, P<0.003] and by differing improvement on relevant subscales (P<0.05). MID was 0.45 on a seven-point response scale. Poorer quality of life at baseline increased the odds by over 2.0 of no improvement in HRQL scores 6-month time-point. General maternal health (OR 1.252), number of foods avoided (OR 1.369) and children >9 years (OR 1.173) were also predictors. The model correctly identified 84% of cases below MID. CONCLUSION: The FAQLQ-PF is sensitive to change, and has excellent longitudinal reliability and validity in a food-allergic patient population. The standard error of measurement value of 0.5 points as a threshold for meaningful change in HRQL questionnaires was confirmed. The FAQLQ-PF may be used to identify problems in children, to assess the effectiveness of clinical trials or interventions, and to guide the development of regulatory policies.

Health-related quality of life of food allergic patients: comparison with the general population and other diseases.

BACKGROUND: To date no studies have compared generic health-related quality of life (HRQL) of food allergic patients from childhood to adulthood with that of the general population or patients with other chronic diseases. The aim of this study was to compare generic HRQL of food allergic patients with the general population and other diseases. METHODS: Generic HRQL questionnaires (CHQ-CF87 and RAND-36) were completed by 79 children, 74 adolescents and 72 adults with food allergy. The generic HRQL scores were compared with scores from published studies on the general population and patients with asthma, irritable bowel syndrome (IBS), diabetes mellitus (DM) and rheumatoid arthritis (RA). RESULTS: Food allergic children and adolescents reported fewer limitations in school work due to behavioural problems (P < or = 0.013), but food allergic adolescents and adults reported more pain (P = 0.020), poorer overall health (P < 0.001), more limitations in social activities (P < 0.001) and less vitality (P = 0.002) than individuals from the general population. Food allergic patients reported poorer generic HRQL than patients with DM, but better generic HRQL than patients with RA, asthma and IBS. CONCLUSION: HRQL is impaired in food allergic adolescents and adults, compared to the general population, and it is intermediate in magnitude between DM and RA, asthma and IBS. Children show the least impact on generic HRQL from food allergy.

Health-related quality of life of food allergic patients measured with generic and disease-specific questionnaires.

BACKGROUND: Health-related quality of life (HRQL) has never been measured with both generic and disease-specific questionnaires in the same group of food allergic patients. The aim of this study was to compare HRQL of food allergic patients as measured with generic and disease-specific questionnaires. METHODS: Generic questionnaires (CHQ-CF87 and RAND-36) and disease-specific HRQL questionnaires (FAQLQ-CF, -TF and -AF) were completed by 79 children, 74 adolescents and 72 adults with food allergy. Floor and ceiling effects, percentage of agreement and multivariate stepwise regression analysis were used to compare the generic and disease-specific measurements. RESULTS: The Food Allergy Quality of Life Questionnaires (FAQLQs) showed minimal floor or ceiling effects. The CHQ-CF87 and RAND-36 showed minimal floor effects, but remarkable ceiling effects (> 73%) were found for the scales role functioning-emotional (RE), role functioning-behaviour (RB), role functioning-physical (RP) in children and adolescents and the scale RE (> 79%) in adults. Additionally, we found low percentages of agreement between the generic and disease-specific questionnaires to identify the same food allergic patients with the best or worst HRQL. Only patients with the best disease-specific HRQL also tended to have the best generic HRQL. Finally, the explained variance in HRQL by patient characteristics was higher in the disease-specific questionnaires (30.7-62.8%) than in the generic scales (6.7-31.7%). CONCLUSION: Disease-specific HRQL questionnaires may be more suitable to measure clinically important impairments in HRQL or HRQL differences over time in food allergic patients. However, generic HRQL questionnaires are indispensable for the comparison between different diseases and are thus complementary.

Development, validity and reliability of the food allergy independent measure (FAIM).

BACKGROUND: The Food Allergy Quality of Life Questionnaire-Child Form, -Teenager Form and -Adult Form (FAQLQ-CF, -TF and -AF) have recently been developed. To measure construct validity in the FAQLQs, a suitable independent measure was needed with which FAQLQ scores could be correlated. However, in food allergy, no appropriate independent measure existed, which could be used for this purpose. AIMS OF THE STUDY: The aim of this study was to describe the development of a Food Allergy Independent Measure Child-Form, -Teenager Form and -Adult Form (FAIM-CF, -TF and -AF) and to assess their validity and reliability. METHODS: The FAIMs were developed using previously established methodology to capture the patients' expectation of outcome (EO). Face validity was determined by expert opinion. FAIM questions showing no correlation to any potential items in the FAQLQs were considered irrelevant and eliminated. To measure test-retest reliability, one-hundred and one patients were included and completed the FAIM twice with a 10-14 day interval. The intraclass correlation coefficient (ICC), Lin's concordance correlation coefficient (CCC) and Bland-Altman plots were used to assess test-retest reliability. RESULTS: Six FAIM questions were developed and considered relevant for the FAIM-CF and -AF, and five questions were relevant for the FAIM-TF. The FAIMs showed good reliability with ICCs and CCCs above 0.70 and with mean differences all close to zero. CONCLUSIONS: Food allergy independent measures were developed for children, adolescents and adults and were shown to be valid, relevant and reliable. This supports the suitability of the FAIMs for evaluating construct validity.