Increased risk of cardiovascular and cerebrovascular diseases in individuals with ankylosing spondylitis: a population-based study.

OBJECTIVE: To estimate the excess risk of cardiovascular and cerebrovascular diseases among individuals with ankylosing spondylitis (AS) in Quebec compared with the general population of Quebec. METHODS: A retrospective cohort study was conducted using population-based administrative data from Quebec. The cohort included all adult individuals with at least 1 AS diagnosis on physician billing or hospital discharge records between 1996 and 2006. A comparison cohort was generated using a 1% random sample of individuals without AS. Cardiovascular and cerebrovascular diseases, and associated hospitalizations, were classified into 1 of 6 subcategories: congestive heart failure, valvular (aortic or nonaortic) heart disease, ischemic heart disease, cerebrovascular disease, or "other" cardiovascular disease. The age- and sex-stratified prevalence estimates, and standardized prevalence ratios, of cardiovascular or cerebrovascular disease in patients with AS, compared to that in the general population, were calculated. RESULTS: The AS cohort included 8,616 individuals diagnosed over the period 1996-2006. The prevalence of cardiovascular and cerebrovascular diseases increased with increasing age for all cardiovascular disease subgroups, and was similar for individuals of both sexes. Age- and sex-stratified prevalence ratios were highest in younger individuals with AS. The age- and sex-standardized prevalence ratios comparing the risk among those with AS to the risk in the general population were as follows: for aortic valvular heart disease 1.58 (95% confidence interval [95% CI] 1.31-1.91), for nonaortic valvular heart disease 1.58 (95% CI 1.43-1.74), for ischemic heart disease 1.37 (95% CI 1.31-1.44), for congestive heart failure 1.34 (95% CI 1.26-1.42), for "other" cardiovascular disease 1.36 (95% CI 1.29-1.44), for cerebrovascular disease 1.25 (95% CI 1.15-1.35), and for any hospitalization for a cardiovascular or cerebrovascular disease 1.31 (95% CI 1.22-1.41). CONCLUSION: Compared with the general population, patients with AS are at increased risk for many types of cardiovascular and cerebrovascular diseases, and are more likely to be hospitalized for these diseases. The excess risk is greatest in younger patients with AS.

Economics of switching to second-line antiretroviral therapy with lopinavir/ritonavir in Africa: estimates based on DART trial results and costs for Uganda and Kenya.

BACKGROUND: Substantial immunological improvement has been reported for HIV-infected patients who switch from a failing regimen to a protease inhibitor regimen with Lopinavir/ritonavir (LPV/r). We use decision analysis modeling to estimate health and economic consequences expected from this switch. METHODS: A Markov model combined best evidence for CD4(+) T-cell response, infectious disease events, death rates, and quality of life for African populations with Kenyan and Ugandan data on drug and medical care costs. We estimate the incremental cost-effectiveness ratio of switching to an LPV/r-based regimen versus remaining on a failed first antiretroviral (ARV) regimen or discontinuing all ARV drugs. The model assumes concurrent use of cotrimoxazole, and 4% annual loss to follow-up. Local effects due to prevalence of malaria and tuberculosis are included in the model. Sensitivity analysis examines the effects of varying disease, ARV therapy and CD4(+) T-cell cost, and ART discontinuation assumptions. RESULTS: The base model estimates an improvement of 20 months in average survival for the LPV/r group. The respective LPV/r ICER for Kenya is $1483 per quality-adjusted life year (QALY) compared to $1673/QALY for Uganda. The ICERs increase to $1517 and $1707, respectively, if CD4(+) T-cell tests cost $25. The model comparing switching to LPV/r to discontinuing all ARV drugs decreases both costs and benefits proportionally for the treatment groups. CONCLUSION: The estimates are clearly below the most stringent World Health Organization benchmark for cost-effectiveness for Kenya and within the acceptable range of cost-effectiveness for Uganda. Thus, the switch to second-line therapy with LPV/r in these countries appears to be a cost-effective use of resources.