Background
We compared the quality of life perceived by patients with non-specific low back pain with that predicted by the social tariff
of the Spanish version of EQ-5D questionnaire.
Methods
For each health state of the EQ-5D, an adjusted tariff for patients with back pain was obtained using a linear regression
model in which the linear effect of the three levels of response for each of the five domains of the EQ-5D was assumed. These
coefficients were compared with those obtained for the general Spanish population. In another model, equal in structure to
the standard “Dolan N” model, the linear effect of the five domains was not assumed.
Results
In 633 patients, 93 health states were recorded. Significant differences in the coefficients of self-care (p = 0.003) and the maximum level of severity in any dimension (p < 0.0001) were observed. The social tariff of the healthy population is different from the tariff of low back pain patients,
with general population values being lower than those of patients, particularly in the 211 health states in which any dimension
is at level 3. Weights of the different EQ-5D dimensions showed a non-linear effect on the patients’ quality of life.
Conclusion
Methods used to develop the social tariff for the Spanish version of EQ-5D were inadequate. In addition, this study shows
that values given by the general population are different from those of low back pain patients, further confirming that the
social tariff of EQ-5D should not be used with actual patients.
Keywords EQ-5D - Health-related quality of life - Low back pain - Preference assessment
Other members of the Spanish Back Pain Research Network who authored this study are: Alfonso Muriel, Unidad de Bioestadística
Clínica, Hospital Ramón y Cajal, Madrid; María Teresa Gil del Real, Margarita Martín, and Severo Santos, Fundación Kovacs,
Madrid; Mario Gestoso and Nicole Mufraggi, Fundación Kovacs, Palma de Mallorca; Carlos Tourne and Luz Marín, Centro de Salud
Abanilla, Murcia; Violeta González, Loreto Palacios, Jaime Mardones, José Estévez, and Esther Marzo, Centro de Salud Albia,
Bilbao; Antonio Bennasar, Servicio de Traumatología, Hospital de Son Dureta, Palma de Mallorca; Sergio Luna, Bartolomé Leal,
and José Nieto Centro de Salud Alburquerque, Badajoz; Juan García and Dolores Jiménez, Centro de Salud Alcolea del Pinar,
Guadalajara; José Martín, Lourdes Cossio, and María Jesús Santero, Centro de Salud Aranjuez II, Madrid; Antoni Jover and Patricia
Ibáñez, Centro de Salud Arquitecto Bennassar, Palma de Mallorca; Manuel Chaparro and Roberto Ruiz, Centro de Salud Balconcillo,
Guadalajara; Isabel Barrio and Angélica Fajardo, Centro de Salud Cadalso, Madrid; Magdalena Pagés, Victoria Portugués, and
Carmen Santos, Centro de Salud Ca’n Misses, Ibiza; Salvador Segura, Magnolia Delgado, Isidro Sanz, and Enriqueta Viñuelas,
Centro de Salud Carrascosa del Campo, Cuenca; Amaia Kareaga, Bakarne Amutxategui, Mónica Fernández, and José M. Gendive, Centro
de Salud Casco Viejo, Bilbao; Rosario Martín, Centro de Salud Cebreros, Madrid; Antonio Ruiz, Samuel Borregón, and José Villares,
Centro de Salud Ciudades, Getafe, Madrid; Sebastián Ribot, Josep Coll, Elena Duro, María Arrate Olivera, and Vicente Reyes,
Centro de Salud Coll D’en Rebassa, Palma de Mallorca; Agustín Martín, Noelia Herranz, and Deborah Jiménez, Centro de Salud
Eras del Bosque, Palencia; Antonio Cordero, Centro de Salud Formentera, Formentera; Mari Luz Besteiro, María Concepción Vargas-Machuca,
and Rosario Martín, Centro de Salud Guayaba, Madrid; Luis Miguel Rubiera, Isabel Aguilar, Urbano López, María Dolores San
Román, and Consuelo Sánchez, Centro de Salud Guzmán el Bueno, Madrid; Ezequiel Arranz and Ana Bellón, Centro de Salud Isabel
II, Parla, Madrid; Esther Thomas, María José Nadal, Gregorio Rodríguez, and Alicia Sánchez, Centro de Salud Jazmín, Madrid;
Purificación González and Baldomero Navalón, Centro de Salud Los Castillos, Madrid; Ana Rosa Escrivá, Herminia Moreno, and
Jesús Rubio, Centro de Salud Palomares, Leganés, Madrid; Luis González, Jesús Martínez, and Consuelo García, Centro de Salud
Paterna, Valencia; María Angeles Usero, Mercedes Arnalte, and Mercedes Rojo, Centro de Salud Perales del Río, Getafe, Madrid;
Carlos Isanta and Natalia Giménez, Centro de Salud Perpetuo Socorro, Huesca; Antonio de Torres, Centro de Salud Pinto, Madrid;
Francisco Gordillo, Luis Enrique Morales, and Juan Carlos Vergara, Centro de Salud Pintores, Madrid; Carlos Rubio, Centro
de Salud Plaza Argel, Cáceres; Miguel Angel Castillo, Centro de Salud Puerta Bonita I, Madrid; Ramón Vercher, Gloria Albert,
Antonio Maura, Gloria Díaz, Eugenio Fernández, Isabel Gil, and Josefina Moreno, Centro de Salud Salvador Allende, Valencia,
Pablo Puente, Centro de Salud San Agustín, Burgos; Juan Gili, Centro de Salud Santa Catalina, Palma de Mallorca; Antonio Cordero
and Ricardo Llido, Centro de Salud Santa Eulalia, Ibiza; Elena Rodríguez, Juana González, and Carmen Nicolau, Centro de Salud
S’Escoxador, Palma de Mallorca; Marina Gómez, Catalina Mateu, Lourdes Perelló, José Bauzá, and Juana Ripoll, Centro de Salud
Son Serra/La Vileta, Palma de Mallorca; Miguel Llinas, Patricia Pascual, and Jaume Ripoll, Centro de Salud Valldargent, Palma
de Mallorca; and Victoria Portugués, Unidad Básica Jesús, Ibiza, Spain.