Investigator

Jabulani Ncayiyana

Associate Professor · University of Pretoria, Health Systems and Public Health

Research Interests

JNJabulani Ncayiyana
Papers(4)
Investigating Drug Tr…Overall Observed Surv…Cost Analysis Related…Cancer in HIV-positiv…
Collaborators(7)
Themba G. GinindzaAndre BovellMazvita MuchengetiMarcel ZwahlenVictor OlagoTafadzwa DhokoteraMatthias Egger
Institutions(4)
University Of Kwazulu…University of the Wit…Bern University of Ap…National Institute fo…

Papers

Investigating Drug Treatment Costs and Patient Characteristics of Female Breast, Cervical, Colorectal, and Prostate Cancers in Antigua and Barbuda: A Retrospective Data Study (2017–2021)

Cancers are problematic for health systems globally, including in Antigua and Barbuda, where understanding the changing extent of common cancers is key to implementing effective prevention and control strategies. This study aimed to assess the relationship between treatment rates and drug treatment costs along with characteristics affecting these costs for patients with female breast, cervical, colorectal and prostate cancers in Antigua and Barbuda from 2017 to 2021. A retrospective observational study design was used. Estimates of age-standardized treatment rates and drug treatment costs were determined using direct standardization and a micro-costing approach, respectively. Linear regression was used to evaluate the relationship between age-standardized treatment rates and drug treatment costs. Model independent variables were assessed for multicollinearity and residuals examined for variance and normality. With a sum of 242 cases identified for this study, each cancer type showed evidence of strong positive correlations and significant associations between treatment costs and age-standardized treatment rates. The mean cost (USD) of drug treatment was highest for female breast (USD 25,009.63) and colorectal (USD 13,317.16) cancers and lowest for prostate (USD 12,528.10) and cervical (USD 5121.41) cancers, with several variables showing significance in the respective final models. An association existed between age-standardized treatment rates and drug treatment costs for the cancers studied. These results offer a basis for encouraging strategies in obtaining affordably priced cancer medicines in Antigua and Barbuda.

Overall Observed Survival of Female Breast, Cervical, Colorectal, and Prostate Cancers in Antigua and Barbuda, 2017–2021: Retrospective Data from Four Study Sites

Understanding cancer survival is important for countries such as Antigua and Barbuda, where female breast, cervical, colorectal, and prostate cancers are burdensome to the healthcare system. This study therefore aimed to estimate the survival probabilities of patients diagnosed with these cancers between 2017 and 2021. A retrospective analytical study design was used to evaluate cancer cases abstracted from medical records at key study sites. Estimates of observed survival probabilities were determined using a Kaplan–Meier analysis. Significant differences between survival curves were assessed using the log-rank test. Hazard ratios were calculated using Cox regression. A p-value < 0.05 indicated significance. A total of 391 diagnosed cases were included in this study (2017–2021): female breast cancer accounted for 42%, cervical cancer accounted for 10%, colorectal cancer accounted for 20%, and prostate cancer accounted for 28%. Overall, the mean age of the participants was 61.5 (±12.9) years; 62% were female, 73% were aged > 55 years, 56% were from St. John’s, and 82% were alive at the end of 2021. The median overall survival (years) was 4.8 for female breast cancer, 4.1 for cervical cancer, 4.5 for colorectal cancer, and not reached for prostate cancer. The cancer-specific overall observed 5-year survival probabilities were 44.9% for female breast cancer, 10.8% for cervical cancer, 19.6% for colorectal cancer, and 69.0% for prostate cancer. Significant associations between disease stage and overall survival were observed in female breast and colorectal cancers. This study provides important evidence for the 5-year observed survival probabilities of the studied cancers. Healthcare improvements that support cancer survival are required.

Cost Analysis Related to Diagnosis, Treatment and Management of Cervical Cancer in Antigua and Barbuda: A Prevalence-Based Cost-of-Illness Study

Cervical cancer remains a significant public health issue globally. In Antigua and Barbuda, cervical cancer is ranked among the top five most common cancers in terms of incidence and mortality among females. There is no evidence that the costs of diagnosing, treating, and managing this cancer have been studied before in Antigua and Barbuda. From the providers’ perspective, this study aimed to estimate costs associated with cervical cancer in Antigua and Barbuda. The prevalence-based cost-of-illness methodology was used to assess patient data abstracted from four study sites for the period 2017–2021, and to derive the annual prevalence. Top-down and bottom-up costing approaches were used to estimate direct medical costs. Costs were computed using the 2021 price level and converted to United States Dollars (USD). Total annual direct medical costs of cervical cancer were estimated at USD 0.24 million (ranging between USD 0.19 million and USD 0.30 million). Major cost drivers were treatment (USD 112,863.76), post-treatment side-effects care (USD 67,406.57), and the diagnostic process (USD 26,238.58). The overall direct medical unit costs for managing a case were estimated at USD 115,822.09. Our study reflects the current estimates for managing cervical cancer and provides evidence to complement cervical cancer prevention and cost containment measures in Antigua and Barbuda.

Cancer in HIV-positive and HIV-negative adolescents and young adults in South Africa: a cross-sectional study

Objective To determine the spectrum of cancers in adolescents and young adults (AYAs) living with and without HIV in South Africa. Design Cross-sectional study with cancer records provided by the National Cancer Registry (NCR) and HIV records from the National Health Laboratory Service (NHLS). Setting and participants The NHLS is the largest provider of pathology services in the South African public sector. The NCR is a division of the NHLS. We included AYAs (aged 10–24 years) diagnosed with cancer by public health sector laboratories between 2004 and 2014 (n=8479). HIV status was obtained through record linkages and text mining. Primary and secondary outcomes We determined the spectrum of cancers by HIV status in AYAs. We used multivariable logistic regression to describe the association of cancer in AYAs with HIV, adjusting for age, sex, ethnicity and calendar period. We imputed (post hoc) the HIV status for AYA with unknown HIV status. Results 8479 AYAs were diagnosed with cancer, HIV status was known for 45% (n=3812). Of those whose status was known, about half were HIV positive (n=1853). AYAs living with HIV were more likely to have Kaposi’s sarcoma (adjusted OR (aOR) 218, 95% CI 89.9 to 530), cervical cancer (aOR 2.18, 95% CI 1.23 to 3.89), non-Hodgkin’s lymphoma (aOR 2.12, 95% CI 1.69 to 2.66) and anogenital cancers other than cervix (aOR 2.73, 95% CI 1.27 to 5.86) than AYAs without HIV. About 44% (n=1062) of AYAs with HIV-related cancers had not been tested for HIV. Conclusions Targeted HIV testing for AYAs diagnosed with cancer, followed by immediate start of antiretroviral therapy, screening for cervical precancer and vaccination against human papilloma virus is needed to decrease cancer burden in AYAs living with HIV in South Africa.

50Works
4Papers
7Collaborators
Uterine Cervical NeoplasmsColorectal NeoplasmsProstatic NeoplasmsBreast NeoplasmsHIV InfectionsInfectious Disease Transmission, Vertical

Positions

2025–

Associate Professor

University of Pretoria · Health Systems and Public Health

2020–

Senior Epidemiologist/Senior Lecturer

University of KwaZulu-Natal · Public Health

2018–

Epidemiologist/Senior Lecturer

University of Cape Town · Epidemiology and Biostatistics

2014–

Lecturer

University of the Witwatersrand · Epidemiology and Biostatistics

Education

2015

PhD

University of North Carolina at Chapel Hill · Epidemiology

2009

MSc

University of the Witwatersrand · Epidemiology and Biostatistics

2001

BSc(Hons)

University of KwaZulu-Natal · Microbiology

2000

BSc

University of KwaZulu-Natal · Microbiology and Biochemistry

Country

ZA

Keywords
EpidemiologyInfectious diseasesTBHIVCancerChild health