Turkiye Klinikleri Journal of Biostatistics

.: ORIGINAL RESEARCH
Cox PH Regression and Homogeneous Semi-Markov Models for Identification of Risk Factors of HIV/AIDS Patients Taking HAART and Assessing the Disease Progression
HAART Alan HIV/AIDS Hastalarının Risk Faktörlerinin ve Hastalık Progresyonunun Tanımlanması İçin Cox PH Regresyonu ve Homojen Semi-Markov Modelleri
Ashenafi KALAYUa, Mekonnen TADESSEb
aWoldia University, Woldia, ETHIOPIA
bAddis Ababa University, Department of Statistics, Addis Ababa, ETHIOPIA
Turkiye Klinikleri J Biostat. 2020;12(2):168-82
doi: 10.5336/biostatic.2019-73148
Article Language: EN
Full Text
ABSTRACT
 Objective: The objectives of the study were to identify the determinant factors for survival time of Human immunodeficiency virus (HIV) infected patients treated with highly active antiretroviral therapy (HAART) and to observe the HIV progression of HIV infected patients in Hawassa City Adare hospital, Ethiopia. Material and Methods: This was a retrospective cohort study of 330 patients who started ART between 2008 and 2014 at Hawassa City Adare Hospital. Data were extracted from paper based medical records database and the survival of patients was estimated by the Kaplan-Meier method. Predictors of mortality were identified by Cox proportional hazards model and the progression of the AIDS patients by Homogeneous Semi-Markov Stochastic model. Results: Survival of patients was significantly related with age, sex, Tuberculosis (TB) status, HIV disclosure, functional status, substance use, baseline World Health Organization (WHO) clinical stage, baseline weight and baseline cluster of differentiation 4 (CD4) count. Results of the Cox PH model revealed that; older, TB co-infected, substance user patients, and patients with lower baseline CD4 count and weight had significantly higher risk of death or shorter survival time than their counterparts. The results of Homogeneous Semi-Markov Stochastic model indicated that AIDS patients in the first state of the disease had the highest survival probability as compared to the patients in the second, third and fourth stage of the disease. Conclusion: To minimize deaths, more attention should be given during the early phases of treatment of HIV/AIDS patients on HAART.

Keywords: Cox proportional hazard model; HIV progression; Semi-Markov model
ÖZET
 Amaç: Bu çalışmada, Etiyopya Hawassa Şehri Adare Hastanesi'nde yüksek düzeyde aktif antiretroviral tedavi (HAART) ile tedavi edilen, insan immün yetmezlik virüsü (HIV) enfeksiyonu ile enfekte hastaların sağkalım süreleri için belirleyici faktörlerin tanımlanması ve HIV ile enfekte hastalarda HIV progresyonunun gözlemlenmesi amaçlanmıştır. Gereç ve Yöntemler: Bu, Hawassa Şehri Adare Hastanesi'nde 2008-2014 yılları arasında antiretroviral tedavi başlanan 330 hastanın retrospektif bir kohort çalışmasıydı. Veriler, kağıt bazlı tıbbi kayıtlar veri tabanından çıkarılmış ve hastaların sağkalımları Kaplan-Meier metodu ile tahmin edilmiştir. Mortalitenin öngördürücüleri Cox orantılı risk modeli ile ve kazanılmış bağışıklık yetersizliği sendromu (AIDS) hastalarının progresyonu homojen semi-Markov stokastik modeli ile tanımlanmıştır. Bulgular: Hastaların sağkalımı yaş, cinsiyet, tüberküloz (TB) durumu, HIV durumu, işlevsel durum, madde kullanımı, Dünya Sağlık Örgütü'ne (DSÖ) göre başlangıçtaki klinik evre, başlangıç kilosu ve farklılaşma kümesi 4 (CD4) sayısı ile anlamlı olarak ilişkiliydi. Cox orantılı risk modelinin sonuçlarına göre; daha yaşlı, TB ile birlikte enfekte olmuş, madde kullanan hastalar ve daha düşük başlangıç CD4 sayısı ve ağırlığı olan hastalar benzerlerine göre daha yüksek ölüm oranlarına veya daha kısa sağkalım süresine sahiplerdi. Homojen semi-Markov stokastik modelin sonuçları, hastalığın birinci evresindeki AIDS hastalarının, hastalığın ikinci, üçüncü ve dördüncü evresindeki hastalara kıyasla en yüksek sağkalım olasılığına sahip olduğunu göstermiştir. Sonuç: Ölümleri en aza indirmek için, HAART tedavisi gören HIV/AIDS hastalarının tedavisinin erken evrelerinde daha fazla dikkat gösterilmelidir.

Anahtar Kelimeler: Cox oransal risk modeli; HIV progresyonu; Semi-Markov modeli
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