Study to Evaluate the Prevalence of Hepatitis C in Spain in 2015 (PREVHEP)
Condition: Hepatitis C; Hepatitis B
MeSH terms: Hepatitis A; Hepatitis C; Hepatitis B; Hepatitis
Study type: Observational

Summary: 
      The hypothesis of this investigation stresses that the current understanding of the
      prevalence of HCV infection in the general population and in different subgroups will serve
      to lay out medium- and long-term measures for action geared toward reducing the disease
      burden through preventive, research, screening and therapeutic measures.

      Aim: To determine the prevalence of seropositivity and chronic infection with the HCV and to
      analyze the associated factors. To analyze and infer different screening strategies for HCV
      infection based on the at-risk groups/cohorts of elevated prevalence detected. to assess the
      efficiency of screening strategies and the subsequent cost-effectiveness of treatment in the
      general population
    

Detailed description: 
      Design of the study: Seroepidemiological and virological study of cross-sectional
      population-based.

      Patients and sampling: The study population has been distributed in groups according to age
      (20-34; 35-49; 50-74 years) and sex. In order to select a representative sample of this
      overall population, three Spanish regions will be selected on the basis of their different
      HCV-related hospitalisation rates defined as follows: high, >120 cases/100,000 inhabitants
      (Madrid); medium, 90-119 cases/100,000 inhabitants (Cantabria); or low, <90 cases/100,000
      inhabitants (Valencia).

      The participants will be selected through a random, representative sample using our two-stage
      conglomerate sampling with stratification of the First-Stage Units. These FSUs are made up by
      the Basic Health Areas (Health Centers). The Second-Stage Units are made up by the
      individuals. The stratification criteria used in the first stage will be the socioeconomic
      status-rural/urban environment. The selection of sample elements will be carried out through
      simple random sampling from the healthcare card database pertaining to the selected Health
      Centers. A sequence of random, computer-generated numbers will be obtained.

      Sample size: In order to achieve an accuracy of 0.4% in the estimate of a percentage through
      a two-tailed 95% confidence interval, assuming the prevalences indicated by age strata in the
      general Spanish population (0.6%, 1.9% and 2.7% respectively), a total of 12,263 subjects
      distributed as follows: 1,456 aged 20-34 years, 4,476 aged 35-49 years and 6,331 aged 50-74
      years.

      Anticipating an uptake of 9-15%,21 following invitation via telephone, between 81,753 and
      136,255 subjects distributed over the three regions needed to be contacted at random.

      Recruitment method for randomized patients. Selected subjects will be called by phone by
      trained personnel. The subject will be invited to report for an interview in order to carry
      out a socio-healthcare questionnaire, a physical examination, and an analytical test. In the
      event the patient refuses to participate, permission shall be requested to collect minimum
      anonymous data for the subsequent study of possible screening biases. Patients meeting
      inclusion criteria and provide written informed consent to be included in the study.

      Variables in the study: socio-healthcare questionnaire includes variables such as age, sex,
      socioeconomic status, risk factors, health habits, etc. Analytical variables (blood count,
      biochemistry, serologies for HBV and HCV, etc.) are collected. A Fibroscan is also performed.
      A cost-effectiveness of screening strategies and treatment will be analysed using a Markov
      model

      Full duration: 21 months
    

Observational model: Other
Time perspective: Cross-Sectional
Sampling method: Probability Sample
Study population: 
        General population aged 20-74 years who agree to participate when contacted by phone call
        after a two-stage conglomerate sampling with stratification of the First-Stage Units.

        The study will be carried out in three Autonomous Communities (regions) in Spain.
      
Biospecimen description: 
      Samples of whole blood, plasma and serum will be collected to analyse different markers
      related to the virus and the medical status of the patients.

      DNA samples will be transferred to the Biobank Valdecilla (Node DNA and fluids) according to
      Spanish law. Law 14/2007 of 3 July, on biomedical research and the Biobank law:

      Royal Decree 1716/2011, establishing the basic requirements for authorization and operation
      of biobanks are established for biomedical research and treatment of biological samples of
      human origin
    
Keywords: Hepatitis; Prevalence; Epidemiology; Infectious diseases