Modelling HIV disease process and progression in seroconversion among South Africa women: using transition-specific parametric multi-state model.

BACKGROUND: HIV infected patients may experience many intermediate events including between-event transition throughout their follow up. Through modelling these transitions, we can gain a deeper understanding of HIV disease process and progression and of factors that influence the disease process and progression pathway. In this work, we present transition-specific parametric multi-state models to describe HIV disease process and progression. METHODS: The data is from an ongoing prospective cohort study conducted amongst adult women who were HIV-infected in KwaZulu-Natal, South Africa. Participants were enrolled during the acute HIV infection phase and then followed up during chronic infection, up to ART initiation. RESULTS: Transition specific distributions for multi-state models, including a variety of accelerated failure time (AFT) models and proportional hazards (PH) models, were presented and compared in this study. The analysis revealed that women enrolling with a CD4 count less than 350 cells/mm3 (severe and advanced disease stages) had a far lower chance of immune recovery, and a considerably higher chance of immune deterioration, compared to women enrolling with a CD4 count of 350 cells/mm3 or more (normal and mild disease stages). Our analyses also showed that older age, higher educational levels, higher scores for red blood cell counts, higher mononuclear scores, higher granulocytes scores, and higher physical health scores, all had a significant effect on a shortened time to immunological recovery, while women with many sex partners, higher viral load and larger family size had a significant effect on accelerating time to immune deterioration. CONCLUSION: Multi-state modelling of transition-specific distributions offers a flexible tool for the study of demographic and clinical characteristics' effects on the entire disease progression pathway. It is hoped that the article will help applied researchers to familiarize themselves with the models, including interpretation of results.

Modelling immune deterioration, immune recovery and state-specific duration of HIV-infected women with viral load adjustment: using parametric multistate model.

BACKGROUND: CD4 cell and viral load count are highly correlated surrogate markers of human immunodeficiency virus (HIV) disease progression. In modelling the progression of HIV, previous studies mostly dealt with either CD4 cell counts or viral load alone. In this work, both biomarkers are in included one model, in order to study possible factors that affect the intensities of immune deterioration, immune recovery and state-specific duration of HIV-infected women. METHODS: The data is from an ongoing prospective cohort study conducted among antiretroviral treatment (ART) naïve HIV-infected women in the province of KwaZulu-Natal, South Africa. Participants were enrolled in the acute HIV infection phase, then followed-up during chronic infection up to ART initiation. Full-parametric and semi-parametric Markov models were applied. Furthermore, the effect of the inclusion and exclusion viral load in the model was assessed. RESULTS: Inclusion of a viral load component improves the efficiency of the model. The analysis results showed that patients who reported a stable sexual partner, having a higher educational level, higher physical health score and having a high mononuclear component score are more likely to spend more time in a good HIV state (particularly normal disease state). Patients with TB co-infection, with anemia, having a high liver abnormality score and patients who reported many sexual partners, had a significant increase in the intensities of immunological deterioration transitions. On the other hand, having high weight, higher education level, higher quality of life score, having high RBC parameters, high granulocyte component scores and high mononuclear component scores, significantly increased the intensities of immunological recovery transitions. CONCLUSION: Inclusion of both CD4 cell count based disease progression states and viral load, in the time-homogeneous Markov model, assisted in modeling the complete disease progression of HIV/AIDS. Higher quality of life (QoL) domain scores, good clinical characteristics, stable sexual partner and higher educational level were found to be predictive factors for transition and length of stay in sequential adversity of HIV/AIDS.

Effect of a three-piece inflatable penile prosthesis combined with a phosphodiesterase-5 inhibitor on erectile dysfunction.

OBJECTIVE: To investigate the therapeutic effect of implanting a three-piece inflatable penile prosthesis (IPP) combined with the phosphodiesterase-5 inhibitor sildenafil in severe erectile dysfunction (ED) patients. METHODS: This randomized controlled study included 123 ED patients. Sixty-two patients received the IPP implantation and 61 patients received the IPP implantation and the phosphodiesterase-5 inhibitor sildenafil. Erectile function and sexual life quality were evaluated using the five-item International Index of Erectile Function (IIEF) and modified Sexual Life Quality Questionnaire-Quality of Life domain (mSLQQ-QoL), respectively. Serum interleukin (IL)-6, IL-8, tumor necrosis factor (TNF)-α, vascular cell adhesion molecule (VCAM)-1, and intercellular adhesion molecule (ICAM)-1 levels were assessed. Kaplan-Meier curves were used to assess the overall IPP survival. RESULTS: Implantation of the three-piece IPP with sildenafil improved erectile function and sexual life quality, alleviated the inflammatory response, reduced the complication rate, and improved overall IPP survival. CONCLUSION: Implantation of the three-piece IPP combined with a phosphodiesterase-5 inhibitor significantly improved clinical outcomes and the prognosis in ED patients.