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food_allergy_definition [2022/07/01 14:20]
laura created
food_allergy_definition [2025/02/05 14:49] (current)
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 ====== Food allergy definition ====== ====== Food allergy definition ======
  
-Researchers from the [[https://​www.rug.nl/​research/​epidemiology/vonk?lang=en|University Medical Center Groningen]] developed a definition of food allergy for all Lifelines participants (adults and children) using the [[allergies|allergy variables]] from [[2A]]. ([[sections]]:​ [[Diseases & symptoms]] ([[Allergies]]) and [[secondary & linked variables]]).\\+Researchers from the [[https://​www.rug.nl/​staff/j.m.vonk/|University Medical Center Groningen]] developed a definition of food allergy for all Lifelines participants (adults and children) using the [[allergies|allergy variables]] from [[2A]]. ([[sections]]:​ [[Diseases & symptoms]] ([[Allergies]]) and [[secondary & linked variables]]).\\
  
-The Food allergy definition can be requested in the Lifelines catalogue or by mail (data@lifelines.nl).\\+The Food allergy definition can be requested in the [[https://data-catalogue.lifelines.nl/|Lifelines catalogue]].\\
 \\ \\
 ===== Background ===== ===== Background =====
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 \\ \\
 ===== Calculation of food allergy definition ===== ===== Calculation of food allergy definition =====
 +The calculation of the food allergy definition consisted of three steps: 1) coding of open text variables, 2) defining and calculating criteria to define food allergy, and 3) creating the overall food allergy variables.
 +\\
 +\\
 +=== 1. Coding of open text variables ===
 +At the start of the process, the responses from participants on "other allergen",​ "other reaction",​ and "other person who diagnosed the food allergy"​ are coded. The allergens and reactions were coded as //common//, //less common//, and //​uncommon//​ using the tables as descibed by [[https://​doi.org/​10.1371/​journal.pone.0231818|Westerlaken-van Ginkel et al. (2020)]]. These original coding tables were slightly changed after reachging consensus. The "other person"​ items have been coded into //​alternative practitioner//,​ //other person//, and //no person mentioned//​.
 +\\
 +\\
  
 +=== 2. Defining and calculating criteria to define food allergy ===
 +For adults, five criteria are included in the questionnaire,​ where the answers to these should not fall in the unlikely category. The unlikely answers are:
 +  * **Criterium 1:** food allergy is only diagnosed by an alternative practitioner
 +  * **Criterium 2:** the onset of symptoms after ingesting the food is after a day or more
 +  * **Criterium 3:** the amount of food that elicits the reaction is a normal portion or more
 +  * **Criterium 4:** the duration of the symptoms is longer than 1 week
 +  * **Criterium 5:** a negative double blind placebo controlled food provocation test
 +\\
 +=== 3. Creating overall food allergy variables ===
 +Food allergy was coded as //no food allergy (0)//, //​indeterminate food allergy (1)//, and //likely food allergy (2)// according to the flow diagram provided in the paper of [[https://​doi.org/​10.1371/​journal.pone.0231818|Westerlaken-van Ginkel et al. (2020)]].
  
-=== 1.  ​=== +For children and adolescents only the two criteria have been asked. As a result, the food allergy definition is based on these two criteria only.For adults, it was decided to include two additional definitions of food allergy: 
 +  - A version without incorporating criterium 3 as there were many participants who reported a likely allergen and a likely reaction while the other four criteria were not unlikely. 
 +  - A version including only criterium 1 and 2, to make the definition comparable to the one for children and adolescents. 
 +\\ 
 +=== Remarks from the UMCG researchers ​=== 
 +  - If a participant has two different questionnaires available, the quetsionnaire with the highest score on food allergy is selected. 
 +  - If a researcher wants to investigate food allergy in both children/​adolescents and adults it is recommended to use //​foodallergy_score_all_c_1//​. If a researcher wants to investigate food allergy in adults only, it is recommended to use //​foodallergy_score_adu_c_2//​ and use the //​foodallergy_score_adu_c_3//​ variable in a sensitivity analysis. 
 +  - In the future the type of foods and the type of reactions will be classified and added. 
 +\\
 \\ \\
 ===== Variables ===== ===== Variables =====
-|**Label English**|**Label Dutch**|**Code**|**Variable**|**Assessment**|**Age**| +| **Label English** ​                                                                                                                                                        ​| **Label Dutch** ​                                                                                                                                                                             | **Code** ​                     | **Variable** ​       | **Assessment** ​ | **Age** ​ 
-|||||||+age at definition of food allergy (based on questionnaire) ​                                                                                                               ​leeftijd ten tijde van definitie voedselallergie (op basis van moment vragenlijst) ​                                                                                                          foodallergy_age_all_c_1 ​      agefa               sec *           all      ​| 
 +| reported product is likely allergenic? ​                                                                                                                                   | gerapporteerd product is waarschijnlijk allergeen? ​                                                                                                                                          | foodallergy_allergen_ach_c_1 ​ | likelyallergen_ach ​ | sec *           | all      | 
 +| reported product is likely allergenic? ​                                                                                                                                   | gerapporteerd product is waarschijnlijk allergeen? ​                                                                                                                                          | foodallergy_allergen_adu_c_1 ​ | likelyallergen_adu ​ | sec *           | all      | 
 +| reported product is likely allergenic? ​                                                                                                                                   | gerapporteerd product is waarschijnlijk allergeen? ​                                                                                                                                          | foodallergy_allergen_chi_c_1 ​ | likelyallergen_chi ​ | sec *           | all      | 
 +| reported reaction is likely allergic? ​                                                                                                                                    | gerapporteerde reactie is waarschijnlijk allergisch? ​                                                                                                                                        | foodallergy_reaction_ach_c_1 ​ | likelyreaction_ach ​ | sec *           | all      | 
 +| reported reaction is likely allergic? ​                                                                                                                                    | gerapporteerde reactie is waarschijnlijk allergisch? ​                                                                                                                                        | foodallergy_reaction_adu_c_1 ​ | likelyreaction_adu ​ | sec *           | all      | 
 +| reported reaction is likely allergic? ​                                                                                                                                    | gerapporteerde reactie is waarschijnlijk allergisch? ​                                                                                                                                        | foodallergy_reaction_chi_c_1 ​ | likelyreaction_chi ​ | sec *           | all      | 
 +| presence of food allergy according to criteria 1 and 2 (excluding criteria 3: amount of food eliciting reaction, 4: duration of symptoms, and 5: result dbpcfc) ​          | aanwezigheid van voedselallergie volgens criteria 1 en 2 (exclusief criteria 3: hoeveelheid voedsel dat reactie uitlokt, 4: duur van symptomen, en 5: resultaat dbpcfc) ​                     | foodallergy_score_ach_c_1 ​    | foodallergy_ach ​    | sec *           | all      | 
 +| presence of food allergy according to criteria 1 and 2 (excluding criteria 3: amount of food eliciting reaction, 4: duration of symptoms, and 5: result dbpcfc) ​          | aanwezigheid van voedselallergie volgens criteria 1 en 2 (exclusief criteria 3: hoeveelheid voedsel dat reactie uitlokt, 4: duur van symptomen, en 5: resultaat dbpcfc) ​                     | foodallergy_score_adu_c_1 ​    | foodallergy3_adu ​   | sec *           | all      | 
 +| presence of food allergy according to criteria 1, 2, 4, and 5 (excluding criteria 3: amount of food eliciting reaction) ​                                                  | aanwezigheid van voedselallergie volgens criteria 1, 2, 4, en 5 (exclusief criteria 3: hoeveelheid voedsel dat reactie uitlokt) ​                                                             | foodallergy_score_adu_c_2 ​    | foodallergy2_adu ​   | sec *           | all      | 
 +| presence of food allergy according to criteria 1, 2, 3, 4, and 5                                                                                                          | aanwezigheid van voedselallergie volgens criteria 1, 2, 3, 4, en 5                                                                                                                           | foodallergy_score_adu_c_3 ​    | foodallergy_adu ​    | sec *           | all      | 
 +| presence of food allergy based on [foodallergy_score_adu_1] and [foodallergy_score_ach/​chi_c_1],​ with the highest score shown in case of multiple scores per participant ​ | aanwezigheid van voedselallergie gebaseerd op [foodallergy_score_adu_1] en [foodallergy_score_ach/​chi_c_1],​ met de hoogste score weergegeven in het geval van meerdere scores per deelnemer ​ | foodallergy_score_all_c_1 ​    | fa3                 | sec *           | all      | 
 +| presence of food allergy based on [foodallergy_score_adu_2] and [foodallergy_score_ach/​chi_c_1],​ with the highest score shown in case of multiple scores per participant ​ | aanwezigheid van voedselallergie gebaseerd op [foodallergy_score_adu_2] en [foodallergy_score_ach/​chi_c_1],​ met de hoogste score weergegeven in het geval van meerdere scores per deelnemer ​ | foodallergy_score_all_c_2 ​    | fa2                 | sec *           | all      | 
 +| presence of food allergy based on [foodallergy_score_adu_3] and [foodallergy_score_ach/​chi_c_1],​ with the highest score shown in case of multiple scores per participant ​ | aanwezigheid van voedselallergie gebaseerd op [foodallergy_score_adu_3] en [foodallergy_score_ach/​chi_c_1],​ met de hoogste score weergegeven in het geval van meerdere scores per deelnemer ​ | foodallergy_score_all_c_3 ​    | fa                  | sec *           | all      | 
 +| presence of food allergy according to criteria 1 and 2 (excluding criteria 3: amount of food eliciting reaction, 4: duration of symptoms, and 5: result dbpcfc) ​          | aanwezigheid van voedselallergie volgens criteria 1 en 2 (exclusief criteria 3: hoeveelheid voedsel dat reactie uitlokt, 4: duur van symptomen, en 5: resultaat dbpcfc) ​                     | foodallergy_score_chi_c_1 ​    | foodallergy_chi ​    | sec *           | all      | 
 + 
 +* The food allergy definition variables are included as assessment '​sec'​ because they link to different questionnaires from assessment [[2A]].
 \\ \\
  
food_allergy_definition.1656678048.txt.gz · Last modified: 2025/02/05 14:49 (external edit)