Psychosocial and sociodemographic predictors of attrition in a longitudinal study of major depression in primary care: the predictD-Spain study

• Published in: Journal of epidemiology and community health (1979) 2010-10, Vol.64 (10), p.874-884
• Main Authors: Bellón, Juan Ángel, de Dios Luna, Juan, Moreno, Berta, Montón-Franco, Carmen, GildeGómez-Barragán, María Josefa, Sánchez-Celaya, Marta, Díaz-Barreiros, Miguel Ángel, Vicens, Catalina, Motrico, Emma, Martínez-Cañavate, María Teresa, Oliván-Blázquez, Bárbara, Vázquez-Medrano, Ana, Sánchez-Artiaga, María Soledad, March, Sebastiá, Muñoz-García, María del Mar, Moreno-Peral, Patricia, Nazareth, Irwin, King, Michael, Torres-González, Francisco
• Format: Article
• Language: English
• Subjects: Adolescent; Adult; Adult and adolescent clinical studies; Age; Aged; Alcohol; bias ME; Biological and medical sciences; Child abuse & neglect; Community health; Depression; Depressive Disorder, Major - diagnosis; Depressive Disorder, Major - epidemiology; Depressive Disorder, Major - psychology; Depressive disorders; Environmental risk; Family physicians; Female; Follow-Up Studies; Gender discrimination; General aspects; Genetic variation; Health Behavior; Humans; Interviews; Logistic Models; Longitudinal Studies; Major depressive disorder; Male; Medical sciences; Mental depression; Middle Aged; Miscellaneous; Modeling; Mood disorders; multilevel models; Outcome Assessment (Health Care); patient dropouts; Patients; Physicians; Polls & surveys; Primary care; Primary health care; primary healthcare; Provinces; Psychology; Psychology. Psychoanalysis. Psychiatry; Psychometrics; Psychopathology. Psychiatry; psychosocial factors; Public health. Hygiene; Public health. Hygiene-occupational medicine; Refusal to Participate - psychology; Refusal to Participate - statistics & numerical data; Research report; Risk Factors; selection bias; Social Class; Sociodemographics; Spain - epidemiology; Studies; Surveys and Questionnaires; Variables; Young Adult
• ISSN: 0143-005X; 1470-2738
• DOI: 10.1136/jech.2008.085290

BackgroundFew data exist on the psychosocial factors associated with attrition in longitudinal surveys. This study was undertaken to determine psychosocial and sociodemographic predictors of attrition from a longitudinal study of the onset and persistence of episodes of major depression in primary care.MethodsA systematic random sample of general practice attendees was recruited in seven Spanish provinces between October 2005 and February 2006. Major depression was diagnosed using the Composite International Diagnostic Interview and a set of 39 individual and environmental risk factors for depression were assessed at baseline and after 6 and 12 months of follow-up. Data were analysed using multilevel logistic regression.Results7777 primary care attendees aged 18–75 years were selected, of whom 1251 (16.1%) were excluded. Of the remaining 6526, 1084 (16.6%) refused to participate. Thus, 5442 patients (attending 231 family physicians in 41 health centres) were interviewed at baseline, of whom 3804 (70%) and 3567 (66%) remained at 6 and 12 months of follow-up, respectively. The province and sociodemographic factors were stronger predictors of attrition than psychosocial factors. Depression and anxiety had no effect but other psychosocial factors affected attrition. There were different profiles for the patients lost at 12 months when predictors measured at baseline versus 6 months were included.ConclusionsThese findings suggest that several psychosocial factors might be considered factors of attrition in primary care cohorts and confirm that baseline characteristics are insufficient for analysing non-response in longitudinal studies, indicating that different retention strategies should be applied for patients interviewed at 6 and 12 months.