El elefante en la habitación

Estamos en el Congreso de la Sociedad Española de Epidemiología. El lema es “Salud en todas las políticas” con alguna mesa sobre crónicos y multimorbilidad pero prácticamente nuestras comunicaciones las únicas sobre ERyME*. Y yo me pregunto ¿Por qué se ignora de esta manera la carga de enfermedad y el impacto de las ERyME en este congreso? Es como si todo fuera diabetes o cáncer. Ya Estitxu demostró que tener una ERyME empeoraba de forma importante la calidad de vida a igual número de enfermedades concomitantes [1]. Por favor, alguien de epi que nos haga caso…

[1] Loza E, Jover JA, Rodriguez L, Carmona L; EPISER Study Group. Multimorbidity: prevalence, effect on quality of life and daily functioning, and variation of this effect when one condition is a rheumatic disease. Semin Arthritis Rheum. 2009 Feb;38(4):312-9

*Y mientras escribo esta reseña, una estupenda a la que no tengo acceso: Comunicación oral 595 DOLOR CRÓNICO EN MAYORES DE 50 AÑOS: ESTUDIO DE SALUD, ENVEJECIMIENTO Y JUBILACIÓN EN EUROPA (SHARE). MC. CIMAS, AA. AYALA, JF. FORJA

¿Pero, entonces, es un estudio transversal o longitudinal?

Buenos días, Loreto. A ver si me puedes aclarar esta duda.
Aun no tengo clara la diferencia entre estudio transversal y longitudinal.
Entiendo que transversal es un periodo limitado en el tiempo y longitudinal sería seguir a los mismos pacientes en diferentes momentos de su vida. ¿Pero entonces un estudio observacional, prospectivo o retrospectivo, que dura dos o tres años puede ser trasversal?

Lo de transversal o longitudinal es en cuanto a la observación de cada paciente, no de todos los pacientes.

En el diseño transversal cada tipo de datos se recoge una sola vez. Esto no quita que un día puedas recoger los datos de la historia y exploración, otro los análisis y otro las pruebas de imagen. Pero cada tipo de datos se recoge una sola vez para cada paciente, de una tacada. No hay que especificar el tiempo de seguimiento en el diseño, porque no hay seguimiento.

En el diseño longitudinal cada paciente tiene al menos dos visitas o momentos de recogida de datos, la basal y la final, y en ambas se pregunta por el outcome, en la basal generalmente para asegurarnos de que este no está presente y en la de seguimiento para ver si el sujeto en estudio lo ha desarrollado o no. Casi siempre hay más de dos visitas, estableciéndose la periodicidad a priori en base a la frecuencia y rapidez de aparición del outcome de interés. El tiempo que transcurre entre la visita basal y la final es la longitud del estudio, que hay que especificar en el diseño.

Recuerda que cuando hablamos del tiempo de un estudio este se refiere al tiempo de observación por paciente, no lo que tardes, o estimes que vas a tardar, en hacer el estudio. Esta última información sobre los tiempos del estudio (periodo de reclutamiento, periodo de recogida de datos, periodo de manejo de datos y análisis…) va en el plan de trabajo, no en el apartado diseño del protocolo.

En algún estudio, lo que nos interesa puede ser ver cómo ha cambiado un parámetro poblacional en el tiempo, por ejemplo, la tasa de cirugías bariátricas de una década a otra. En este caso, aunque se hagan dos medidas en el tiempo, generalmente retrospectivas, las medidas son transversales, porque no afectan a los mismos pacientes. Se hacen dos cortes transversales de la población, no dos observaciones en un paciente.

Espero haber aclarado algo.

News from Eular-Epidemiology (by Deborah Symmons, Chair of Epidemiology and Health Services Research)

eular

Feed-back from the Eular executive

The EULAR Research Foundation has been renamed FOREUM (Foundation for Research in Rheumatology). In future, all applications for primary research will be considered by FOREUM. For the foreseeable future FOREUM will only consider applications within the specified area for that year. The topics for 2014-5 are expected to be ankylosing spondylitis and SLE. The call has not yet been announced but is expected soon via the EULAR website. From now on, EULAR itself will only consider applications for EULAR branded outputs such as guidelines, points to consider and recommendations. If you are considering making an application to either of these funding sources, I would strongly recommend that you visit the EULAR website for guidance and contact me so that we can make sure that the application matches the expectations of those who will consider it for funding.

The EULAR executive recently agreed to fund an application put forward via our committee to develop a questionnaire to be used in studies of ‘pre-RA’ that is to identify individuals with symptoms likely to develop into RA. The project is being led by Dirkjan van Schaardenburg and colleagues in the EULAR study group on risk factors for RA.

News from the Eular Congress

Axel Finkch is now the Chair Elect of our standing committee and Ingemar Petersson is our representative on the scientific committee which is currently planning the 2015 EULAR Congress.
Many thanks to those of you who attended the annual meeting of the standing committee during the EULAR Congress in Paris. A copy of the minutes is attached (available from InMusc) which were kindly taken by Axel and provide an excellent summary of the current and future activities of our committee.
The open meeting at the Paris Congress featured presentations from our two study groups (EULAR RODS and the EULAR Study Group on Public Health). It was called ‘Improving patient care and safety through data acquisition and analysis’. EULAR RODS (Registers and Observational Drug Studies) held a very successful meeting in Prague in November 2013. A further meeting is planned for December 2015. The Study Group on Public Health is continuing the work of EUMuscNET in raising the profile of RMDs in Europe.
Plans for the Rome Congress (10th-13th June 2015) are progressing well. We have already had two meetings to discuss sessions for the ‘Outcomes science’ stream and we have also had input into some of the clinical sessions. The website will open for abstract submission on 1st October 2014 and close on 31st January 2015. Further details are available on the much improved website: www.congress.eular.org. Apparently 50% of abstracts are submitted in the final 24 hours! The ‘Epidemiology and Health Services Research’ topic generally has the largest number of abstracts – well over 300. However many of the abstracts submitted to this topic would fit better with the disease topic to which they apply and are not really epidemiology or health services research! Please encourage your colleagues to consider carefully which topic they select in order that their abstracts be considered by the most appropriate reviewers.

EULAR and the European Parliament

EULAR has an office in Brussels which is dedicated to raising the profile of RMDs throughout Europe and especially within the EU parliament. Prior to the 2013 elections, the EULAR Brussels office contacted many candidates to provide them with some basic information about RMDs and to seek their support. Around 40 of those who expressed an interest have been elected. EULAR are working to expand that group and to provide them with regular and digestible updates. I have been invited to attend a conference for MEPs called: ’Analysing how to reduce barriers to health care for people with chronic diseases in Europe’ which will be held in Brussels on 16th October.
EULAR is starting to work on developing a ‘Roadmap for research’ to be adopted transnationally. This will identify areas of priority to patients, likely to be solvable within a 5-10 year time span, and which have relevance across diseases.

News from the EMA

The EMA is considering the cardiovascular safety of over-the-counter ibuprofen. Please see attached press release (Available at InMusc)