Vaccine value profile for Neisseria gonorrhoeae

Neisseria gonorrhoeae infection (gonorrhoea) is a global public health challenge, causing substantial sexual and reproductive health consequences, such as infertility, pregnancy complications and increased acquisition or transmission of HIV. There is an urgency to controlling gonorrhoea because of increasing antimicrobial resistance to ceftriaxone, the last remaining treatment option, and the potential for gonorrhoea to become untreatable. No licensed gonococcal vaccine is available. Mounting observational evidence suggests that N. meningitidis serogroup B outer membrane vesicle-based vaccines may induce cross-protection against N. gonorrhoeae (estimated 30%-40% effectiveness using the 4CMenB vaccine). Clinical trials to determine the efficacy of the 4CMenB vaccine against N. gonorrhoeae are underway, as are Phase 1/2 studies of a new gonococcal-specific vaccine candidate. Ultimately, a gonococcal vaccine must be accessible, affordable and equitably dispensed, given that those most affected by gonorrhoea are also those who may be most disadvantaged in our societies, and most cases are in less-resourced settings. This vaccine value profile (VVP) provides a high level, holistic assessment of the current data to inform the potential public health, economic and societal value of pipeline vaccines. This was developed by a working group of subject matter experts from academia, non-profit organizations, public private partnerships and multi-lateral organizations. All contributors have extensive expertise on various elements of the N. gonorrhoeae VVP and collectively aimed to identify current research and knowledge gaps. The VVP was developed using published data obtained from peer-reviewed journals or reports.

Post-authorization safety surveillance of Ad.26.COV2.S vaccine: Reports to the Vaccine Adverse Event Reporting System and v-safe, February 2021-February 2022

BACKGROUND

On 2/27/2021, FDA authorized Janssen COVID-19 Vaccine (Ad.26.COV2.S) for use in individuals 18 years of age and older. Vaccine safety was monitored using the Vaccine Adverse Event Reporting System (VAERS), a national passive surveillance system, and v-safe, a smartphone-based surveillance system.

METHODS

VAERS and v-safe data from 2/27/2021 to 2/28/2022 were analyzed. Descriptive analyses included sex, age, race/ethnicity, seriousness, AEs of special interest (AESIs), and cause of death. For prespecified AESIs, reporting rates were calculated using the total number of doses of Ad26.COV2.S administered. For myopericarditis, observed-to-expected (O/E) analysis was performed based on the number verified cases, vaccine administration data, and published background rates. Proportions of v-safe participants reporting local and systemic reactions, as well as health impacts, were calculated.

RESULTS

During the analytic period, 17,018,042 doses of Ad26.COV2.S were administered in the United States, and VAERS received 67,995 reports of AEs after Ad26.COV2.S vaccination. Most AEs (59,750; 87.9 %) were non-serious and were similar to those observed during clinical trials. Serious AEs included COVID-19 disease, coagulopathy (including thrombosis with thrombocytopenia syndrome; TTS), myocardial infarction, Bell's Palsy, and Guillain-Barré syndrome (GBS). Among AESIs, reporting rates per million doses of Ad26.COV2.S administered ranged from 0.06 for multisystem inflammatory syndrome in children to 263.43 for COVID-19 disease. O/E analysis revealed elevated reporting rate ratios (RRs) for myopericarditis; among adults ages 18-64 years, the RR was 3.19 (95 % CI 2.00, 4.83) within 7 days and 1.79 (95 % CI 1.26, 2.46) within 21 days of vaccination. Of 416,384 Ad26.COV2.S recipients enrolled into v-safe, 60.9 % reported local symptoms (e.g. injection site pain) and 75.9 % reported systemic symptoms (e.g., fatigue, headache). One-third of participants (141,334; 33.9 %) reported a health impact, but only 1.4 % sought medical care.

CONCLUSION

Our review confirmed previously established safety risks for TTS and GBS and identified a potential safety concern for myocarditis.

Characteristics of Mpox Vaccine Recipients Among a Sample of Men Who Have Sex With Men With Presumed Exposure to Mpox

ABSTRACT

Mpox vaccination is recommended for persons exposed to or at risk for mpox. Approximately 25% of an online sample of men who have sex with men (MSM) with presumed mpox exposure were vaccinated (≥1 dose). Vaccination was higher among younger MSM, MSM concerned about mpox, or MSM reporting sexual risk behaviors. Incorporating mpox vaccination into routine sexual health care and increasing 2-dose vaccination uptake is essential to preventing mpox acquisition, improving MSM sexual health, and averting future mpox outbreaks.

Healthy Vaccinee Bias and MenB-FHbp Vaccine Effectiveness Against Gonorrhea

ABSTRACT

Observational studies demonstrated 30% to 40% effectiveness of outer-membrane vesicle (OMV) meningococcal serogroup B vaccines against gonorrhea. To explore whether healthy vaccinee bias influenced such findings, we examined the effectiveness of MenB-FHbp, a non-OMV vaccine that is not protective against gonorrhea. MenB-FHbp was ineffective against gonorrhea. Healthy vaccinee bias likely did not confound earlier studies of OMV vaccines.

Reports of Guillain-Barré Syndrome After COVID-19 Vaccination in the United States

IMPORTANCE

Because of historical associations between vaccines and Guillain-Barré syndrome (GBS), the condition was a prespecified adverse event of special interest for COVID-19 vaccine monitoring.

OBJECTIVE

To evaluate GBS reports to the Vaccine Adverse Event Reporting System (VAERS) and compare reporting patterns within 21 and 42 days after vaccination with Ad26.COV2.S (Janssen), BNT162b2 (Pfizer-BioNTech), and mRNA-1273 (Moderna) COVID-19 vaccines.

DESIGN, SETTING, AND PARTICIPANTS

This retrospective cohort study was conducted using US VAERS reports submitted during December 2020 to January 2022. GBS case reports verified as meeting the Brighton Collaboration case definition for GBS in US adults after COVID-19 vaccination were included.

EXPOSURES

Receipt of the Ad26.COV2.S, BNT162b2, or mRNA-1273 COVID-19 vaccine.

MAIN OUTCOMES AND MEASURES

Descriptive analyses of GBS case were conducted. GBS reporting rates within 21 and 42 days after Ad26.COV2.S, BNT162b2, or mRNA-1273 vaccination based on doses administered were calculated. Reporting rate ratios (RRRs) after receipt of Ad26.COV2.S vs BNT162b2 or mRNA-1273 within 21- and 42-day postvaccination intervals were calculated. Observed-to-expected (OE) ratios were estimated using published GBS background rates.

RESULTS

Among 487 651 785 COVID-19 vaccine doses, 17 944 515 doses (3.7%) were Ad26.COV2.S, 266 859 784 doses (54.7%) were BNT162b2, and 202 847 486 doses (41.6%) were mRNA-1273. Of 295 verified reports of individuals with GBS identified after COVID-19 vaccination (12 Asian [4.1%], 18 Black [6.1%], and 193 White [65.4%]; 17 Hispanic [5.8%]; 169 males [57.3%]; median [IQR] age, 59.0 [46.0-68.0] years), 275 reports (93.2%) documented hospitalization. There were 209 and 253 reports of GBS that occurred within 21 days and 42 days of vaccination, respectively. Within 21 days of vaccination, GBS reporting rates per 1 000 000 doses were 3.29 for Ad26.COV.2, 0.29 for BNT162b2, and 0.35 for mRNA-1273 administered; within 42 days of vaccination, they were 4.07 for Ad26.COV.2, 0.34 for BNT162b2, and 0.44 for mRNA-1273. GBS was more frequently reported within 21 days after Ad26.COV2.S than after BNT162b2 (RRR = 11.40; 95% CI, 8.11-15.99) or mRNA-1273 (RRR = 9.26; 95% CI, 6.57-13.07) vaccination; similar findings were observed within 42 days after vaccination (BNT162b2: RRR = 12.06; 95% CI, 8.86-16.43; mRNA-1273: RRR = 9.27; 95% CI, 6.80-12.63). OE ratios were 3.79 (95% CI, 2.88-4.88) for 21-day and 2.34 (95% CI, 1.83-2.94) for 42-day intervals after Ad26.COV2.S vaccination and less than 1 (not significant) after BNT162b2 and mRNA-1273 vaccination within both postvaccination periods.

CONCLUSIONS AND RELEVANCE

This study found disproportionate reporting and imbalances after Ad26.COV2.S vaccination, suggesting that Ad26.COV2.S vaccination was associated with increased risk for GBS. No associations between mRNA COVID-19 vaccines and risk of GBS were observed.

Chemsex Drug Use among a National Sample of Sexually Active Men who have Sex with Men, - American Men's Internet Survey, 2017-2020

Background: Chemsex is the intentional use of drugs to enhance sexual activity. Chemsex drug use among men who have sex with men (MSM) is associated with sexual behaviors that increase sexually transmitted infection (STI) risks and adverse mental health outcomes. However, published data are largely based on MSM recruited from STI clinics. There are limited data about use of chemsex drugs among national samples of MSM in the United States. Using data from the American Men's Internet Survey (AMIS), we assessed the prevalence and correlates of use of chemsex drugs among sexually active MSM in the United States. Methods: We used data from the 2017 to 2020 AMIS cycles to examine the prevalence of chemsex drug use in the past 12 months among MSM. We calculated prevalence ratios (PR) and 95% confidence intervals (CI) to compare chemsex drug use across demographic, behavioral, and mental health factors. Results: Of 30,294 MSM, 3,113 (10.3%) reported chemsex drug use in the past 12 months. Of the 3,113 MSM who reported chemsex drug use, 65.1% reported ecstasy use, 42.5% reported crystal methamphetamine use, and 21.7% reported GHB use. Factors associated with chemsex drug use included condomless anal sex (PR = 1.93, 95%=1.69-2.20), problem drinking (PR = 2.36, 95% = 2.13-2.61), bacterial STI test (1.84, 95% CI = 1.68-2.02) and probable serious mental illness (PR = 1.92, 95% = 1.76-2.09). Conclusion: Chemsex drug use is associated with behaviors that increase STI risk and mental distress among MSM. Health programs that serve MSM can consider screening for chemsex drug use and offering sexual and mental health promotion and risk reduction interventions when necessary.

Safety of COVID-19 Vaccination in United States Children Ages 5 to 11 Years

BACKGROUND AND OBJECTIVES

Limited postauthorization safety data for the Pfizer-BioNTech coronavirus disease 2019 vaccination among children ages 5 to 11 years are available, particularly for the adverse event myocarditis, which has been detected in adolescents and young adults. We describe adverse events observed during the first 4 months of the United States coronavirus disease 2019 vaccination program in this age group.

METHODS

We analyzed data from 3 United States safety monitoring systems: v-safe, a voluntary smartphone-based system that monitors reactions and health effects; the Vaccine Adverse Events Reporting System (VAERS), the national spontaneous reporting system comanaged by the Centers for Disease Control and Prevention and Food and Drug Administration; and the Vaccine Safety Datalink, an active surveillance system that monitors electronic health records for prespecified events, including myocarditis.

RESULTS

Among 48 795 children ages 5 to 11 years enrolled in v-safe, most reported reactions were mild-to-moderate, most frequently reported the day after vaccination, and were more common after dose 2. VAERS received 7578 adverse event reports; 97% were nonserious. On review of 194 serious VAERS reports, 15 myocarditis cases were verified; 8 occurred in boys after dose 2 (reporting rate 2.2 per million doses). In the Vaccine Safety Datalink, no safety signals were detected in weekly sequential monitoring after administration of 726 820 doses.

CONCLUSIONS

Safety findings for Pfizer-BioNTech vaccine from 3 United States monitoring systems in children ages 5 to 11 years show that most reported adverse events were mild and no safety signals were observed in active surveillance. VAERS reporting rates of myocarditis after dose 2 in this age group were substantially lower than those observed among adolescents ages 12 to 15 years.

Safety of mRNA vaccines administered during the initial 6 months of the US COVID-19 vaccination programme: an observational study of reports to the Vaccine Adverse Event Reporting System and v-safe

BACKGROUND

In December, 2020, two mRNA-based COVID-19 vaccines were authorised for use in the USA. We aimed to describe US surveillance data collected through the Vaccine Adverse Event Reporting System (VAERS), a passive system, and v-safe, a new active system, during the first 6 months of the US COVID-19 vaccination programme.

METHODS

In this observational study, we analysed data reported to VAERS and v-safe during Dec 14, 2020, to June 14, 2021. VAERS reports were categorised as non-serious, serious, or death. Reporting rates were calculated using numbers of COVID-19 doses administered as the denominator. We analysed v-safe survey reports from days 0-7 after vaccination for reactogenicity, severity (mild, moderate, or severe), and health impacts (ie, unable to perform normal daily activities, unable to work, or received care from a medical professional).

FINDINGS

During the study period, 298 792 852 doses of mRNA vaccines were administered in the USA. VAERS processed 340 522 reports: 313 499 (92·1%) were non-serious, 22 527 (6·6%) were serious (non-death), and 4496 (1·3%) were deaths. Over half of 7 914 583 v-safe participants self-reported local and systemic reactogenicity, more frequently after dose two (4 068 447 [71·7%] of 5 674 420 participants for local reactogenicity and 4 018 920 [70·8%] for systemic) than after dose one (4 644 989 [68·6%] of 6 775 515 participants for local reactogenicity and 3 573 429 [52·7%] for systemic). Injection-site pain (4 488 402 [66·2%] of 6 775 515 participants after dose one and 3 890 848 [68·6%] of 5 674 420 participants after dose two), fatigue (2 295 205 [33·9%] participants after dose one and 3 158 299 participants [55·7%] after dose two), and headache (1 831 471 [27·0%] participants after dose one and 2 623 721 [46·2%] participants after dose two) were commonly reported during days 0-7 following vaccination. Reactogenicity was reported most frequently the day after vaccination; most reactions were mild. More reports of being unable to work, do normal activities, or of seeking medical care occurred after dose two (1 821 421 [32·1%]) than after dose one (808 963 [11·9%]); less than 1% of participants reported seeking medical care after vaccination (56 647 [0·8%] after dose one and 53 077 [0·9%] after dose two).

INTERPRETATION

Safety data from more than 298 million doses of mRNA COVID-19 vaccine administered in the first 6 months of the US vaccination programme show that most reported adverse events were mild and short in duration.

FUNDING

US Centers for Disease Control and Prevention.

Acceptability of a Gonococcal Vaccine Among Sexually Active Men Who Have Sex With Men

BACKGROUND

Prospects for a gonococcal vaccine have advanced. Vaccine acceptability is crucial to maximizing population-level protection among key groups, such as men who have sex with men (MSM). We assessed the prevalence of gonococcal vaccine acceptability among sexually active MSM in the United States.

METHODS

We used data from the American Men's Internet Study conducted from August 2019 to December 2019. We calculated frequencies of sociodemographic characteristics, vaccine acceptability, and preferred location for vaccine receipt. Using log-binomial regression analyses, we calculated unadjusted prevalence rates (PRs) and 95% confidence intervals (CIs) to evaluate factors associated with vaccine acceptability.

RESULTS

Of 4951 MSM, 83.5% were willing to accept a vaccine and 16.5% were unwilling. Preferred vaccination locations were primary care provider's clinics (83.5%) and sexually transmitted disease (STD) clinics (64.6%). Vaccine acceptability was greater among young MSM (15-24 years [PR, 1.09; 95% CI, 1.05-1.12], 25-29 years [PR, 1.13; 95% CI, 1.09-1.17], and 30-39 years [PR, 1.10; 95% CI, 1.05-1.14] compared with MSM ≥40 years), MSM living with HIV (PR, 1.05; 95% CI, 1.02-1.09), and MSM who reported (in the past 12 months) condomless anal sex (PR, 1.09; 95% CI, 1.06-1.12), a bacterial STD test (PR, 1.18; 95% CI, 1.15-1.21), HIV preexposure prophylaxis use (PR, 1.17; 95% CI, 1.14-1.19), a bacterial STD diagnosis (PR, 1.04; 95% CI, 1.02-1.07), or a health care provider visit (PR, 1.11; 95% CI, 1.06-1.16). Men who have sex with men who reported ≤high school education (PR, 0.93; 95% CI, 0.91-0.97) were less willing to accept a vaccine compared with those with >high school education.

CONCLUSIONS

Most respondents were willing to accept a gonococcal vaccine. These findings can inform the planning and implementation of a future gonococcal vaccination program that focuses on MSM.

Expected Rates of Select Adverse Events following Immunization for COVID-19 Vaccine Safety Monitoring

Using meta-analytic methods, we calculated expected rates of 21 potential adverse events of special interest (AESI) that would occur following COVID-19 vaccination within 1-, 7-, and 42-day intervals without causal associations. Based on these expected rates, if 10,000,000 persons are vaccinated, 0.5, 3.7, and 22.5 Guillain-Barre syndrome cases; 0.3, 2.4, and 14.3 myopericarditis cases; and 236.5, 1655.5, and 9932.8 all-cause deaths would occur coincidentally within 1, 7, and 42 days post-vaccination, respectively. Expected rates of potential AESI can contextualize events associated temporally with immunization, aid in safety signal detection, guide COVID-19 vaccine health communications, and inform COVID-19 vaccine benefit-risk assessments.

COVID-19 Vaccine Safety in Adolescents Aged 12-17 Years - United States, December 14, 2020-July 16, 2021

As of July 30, 2021, among the three COVID-19 vaccines authorized for use in the United States, only the Pfizer-BioNTech BNT162b2 mRNA COVID-19 vaccine is authorized for adolescents aged 12-17 years. The Food and Drug Administration (FDA) issued an Emergency Use Authorization (EUA) for Pfizer-BioNTech vaccine for use in persons aged ≥16 years on December 11, 2020 (1); the EUA was expanded to include adolescents aged 12-15 years on May 10, 2021 (2), based on results from a Phase 3 clinical trial (3). Beginning in June 2021, cases of myocarditis and myopericarditis (hereafter, myocarditis) after receipt of Pfizer-BioNTech vaccine began to be reported, primarily among young males after receipt of the second dose (4,5). On June 23, 2021, CDC's Advisory Committee on Immunization Practices (ACIP) reviewed available data and concluded that the benefits of COVID-19 vaccination to individual persons and the population outweigh the risks for myocarditis and recommended continued use of the vaccine in persons aged ≥12 years (6). To further characterize safety of the vaccine, adverse events after receipt of Pfizer-BioNTech vaccine reported to the Vaccine Adverse Event Reporting System (VAERS) and adverse events and health impact assessments reported in v-safe (a smartphone-based safety surveillance system) were reviewed for U.S. adolescents aged 12-17 years during December 14, 2020-July 16, 2021. As of July 16, 2021, approximately 8.9 million U.S. adolescents aged 12-17 years had received Pfizer-BioNTech vaccine.* VAERS received 9,246 reports after Pfizer-BioNTech vaccination in this age group; 90.7% of these were for nonserious adverse events and 9.3% were for serious adverse events, including myocarditis (4.3%). Approximately 129,000 U.S. adolescents aged 12-17 years enrolled in v-safe after Pfizer-BioNTech vaccination; they reported local (63.4%) and systemic (48.9%) reactions with a frequency similar to that reported in preauthorization clinical trials. Systemic reactions were more common after dose 2. CDC and FDA continue to monitor vaccine safety and provide data to ACIP to guide COVID-19 vaccine recommendations.

Planning for a Gonococcal Vaccine: A Narrative Review of Vaccine Development and Public Health Implications

ABSTRACT

Declining gonococcal susceptibility to ceftriaxone and azithromycin has raised the possibility of untreatable gonorrhea in the future and reignited interest in gonococcal vaccine development. Despite decades of research, previous gonococcal vaccine candidates have been ineffective. A growing body of data suggests that meningococcal group B outer-membrane vaccines may be cross-protective against Neisseria gonorrhoeae. Clinical trials of a licensed vaccine against Neisseria meningitidis serogroup B containing an outer-membrane vaccine component are underway to determine its efficacy against N. gonorrhoeae. Other experimental gonococcal vaccine candidates are in the preclinical phases. Population impact of future gonococcal vaccines with different levels of efficacy and duration of protection in various populations is being evaluated using modeling studies. Despite recent progress, gaps in gonococcal vaccine research remain. Research is needed to evaluate vaccine efficacy in preventing gonococcal infections acquired via various anatomic routes and among patients coinfected with other sexually transmitted infections. Studies that model the impact of a future vaccine on high-burden populations such as men who have sex with men and estimate both vaccine cost-effectiveness and the incremental cost-effectiveness ratio of vaccination to antimicrobial resistance and treatment costs are warranted. This narrative review examines the current state of gonococcal vaccine research, the possible impact of a gonococcal vaccine on gonorrhea rates based on modeling studies, gaps in the gonococcal vaccine literature, and public health implications of a future gonococcal vaccine on reducing the gonorrhea burden in the United States.

Bacterial sexually transmitted infection testing and diagnoses among men who have sex with men and report prescription opioid misuse--American Men's Internet Survey, 2017-2018

PURPOSE

Prescription opioid misuse is associated with behaviors which increase bacterial sexually transmitted diseases (STD) risk among men who have sex with men (MSM). Annual syphilis, gonorrhea, and chlamydia screening is recommended for sexually active MSM at anatomical sites of contact, regardless of condom use. We describe the prevalence of self-reported bacterial STD testing and diagnoses in the past 12 months among sexually active MSM who report prescription opioid misuse.

METHODS

We used data from the 2017 and 2018 American Men's Internet Survey to examine the prevalence of self-reported bacterial STD testing and diagnoses in the past 12 months. We calculated unadjusted prevalence ratios, adjusted prevalence ratios (APR), and 95% confidence intervals (CI) to compare bacterial STD testing prevalence across demographic, clinical, and behavioral factors.

RESULTS

Of 932 sexually active MSM who reported prescription opioid misuse, 433 (46.5%) self-reported bacterial STD testing in the past 12 months. Of those who reported being tested, 131 (30.2%) self-reported ≥ 1 bacterial STD. Approximately 50% of respondents who reported condomless anal sex (CAS), casual sex, or exchange sex reported bacterial STD testing in past 12 months. Factors associated with bacterial STD testing among MSM who misused prescription opioids included visiting a healthcare provider in the past 12 months (APR = 1.70, 95% CI = 1.09-2.67), ever disclosing same-sex behavior to a healthcare provider (APR = 1.78, 95% CI = 1.27-2.50), and CAS in the past 12 months (APR = 1.51, 95% CI = 1.10-2.04).

CONCLUSIONS

Prevalence of self-reported bacterial STD testing in this sample was low and one-third of tested MSM reported ≥ 1 bacterial STD in the past 12 months. Innovative approaches to identify MSM who misuse prescription opioids and expand bacterial STD testing in this population are needed.

Disseminated Gonococcal Infections in Patients Receiving Eculizumab: A Case Series

BACKGROUND

Gonorrhea is the second most commonly reported notifiable condition in the United States. Infrequently, Neisseria gonorrhoeae can cause disseminated gonococcal infection (DGI). Eculizumab, a monoclonal antibody, inhibits terminal complement activation, which impairs the ability of the immune system to respond effectively to Neisseria infections. This series describes cases of N. gonorrhoeae infection among patients receiving eculizumab.

METHODS

Pre- and postmarketing safety reports of N. gonorrhoeae infection in patients receiving eculizumab worldwide were obtained from US Food and Drug Administration safety databases and the medical literature, including reports from the start of pivotal clinical trials in 2004 through 31 December 2017. Included patients had at least 1 eculizumab dose within the 3 months prior to N. gonorrhoeae infection.

RESULTS

Nine cases of N. gonorrhoeae infection were identified; 8 were classified as disseminated (89%). Of the disseminated cases, 8 patients required hospitalization, 7 had positive blood cultures, and 2 required vasopressor support. One patient required mechanical ventilation. Neisseria gonorrhoeae may have contributed to complications prior to death in 1 patient; however, the fatality was attributed to underlying disease per the reporter.

CONCLUSIONS

Patients receiving eculizumab may be at higher risk for DGI than the general population. Prescribers are encouraged to educate patients receiving eculizumab on their risk for serious gonococcal infections and perform screening for sexually transmitted diseases (STDs) per the Centers for Disease Control and Prevention STD treatment guidelines or in suspected cases. If antimicrobial prophylaxis is used during eculizumab therapy, prescribers should consider trends in gonococcal antimicrobial susceptibility due to emerging resistance concerns.

Hepatocellular Carcinoma Surveillance in a Cohort of Chronic Hepatitis C Virus-Infected Patients with Cirrhosis

BACKGROUND

Six-monthly hepatocellular carcinoma (HCC) screening in cirrhotic patients has been recommended since 2011. HCC prognosis is associated with diagnosis at an early stage. We examined the prevalence and correlates of 6-monthly HCC surveillance in a cohort of HCV-infected cirrhotic patients.

METHODS

Data were obtained from the medical records of patients receiving care from four hospitals between January 2011 and December 2016. Frequencies and logistic regression were conducted.

RESULTS

Of 2,933 HCV-infected cirrhotic patients, most were ≥ 60 years old (68.5%), male (62.2%), White (65.8%), and had compensated cirrhosis (74.2%). The median follow-up period was 3.5 years. Among these patients, 10.9% were consistently screened 6 monthly and 21.4% were never screened. Patients with a longer history of cirrhosis (AOR = 0.86, 95% CI = 0.80-0.93) were less likely to be screened 6 monthly while decompensated cirrhotic patients (AOR = 1.39, 95% CI = 1.06-1.81) and cirrhotic patients between 18 and 44 years (AOR = 2.01, 95% CI = 1.07-3.74) were more likely to be screened 6 monthly compared to compensated cirrhotic patients and patients 60 years and older respectively. There were no significant differences by race, gender, or insurance type.

CONCLUSION

The prevalence of consistent HCC surveillance remains low despite formalized recommendations. One in five patients was never surveilled. Patients with a longer history of cirrhosis were less likely to be surveilled consistently despite their greater HCC risk. Improving providers' knowledge about current HCC surveillance guidelines, educating patients about the benefits of consistent HCC surveillance, and systemic interventions like clinical reminders and standing HCC surveillance protocols can improve guideline-concordant surveillance in clinical practice.

Age-Related Differences in Past or Present Hepatitis C Virus Infection Among People Who Inject Drugs: National Human Immunodeficiency Virus Behavioral Surveillance, 8 US Cities, 2015

BACKGROUND

Historically, older people who inject drugs (PWID) have had the highest hepatitis C virus (HCV) burden; however, young PWID now account for recent increases. We assessed factors associated with past or present HCV infection (HCV antibody [anti-HCV] positive) among young (≤35 years) and older (>35 years) PWID.

METHODS

We calculated adjusted prevalence ratios (aPRs) and 95% confidence intervals (CIs) to examine sociodemographic and past 12-month injection behaviors associated with HCV infection.

RESULTS

Of 4094 PWID, 55.2% were anti-HCV positive. Among young PWID, anti-HCV prevalence was 42.1% and associated with ≤high school diploma/General Education Development diploma (GED) (aPR, 1.17 [95% CI, 1.03-1.33]), receptive syringe sharing (aPR, 1.37 [95% CI, 1.21-1.56]), sharing injection equipment (aPR, 1.16 [95% CI, 1.01-1.35]), arrest history (aPR, 1.14 [95% CI, 1.02-1.29]), and injecting speedball (aPR, 1.37 [95% CI, 1.16-1.61]). Among older PWID, anti-HCV prevalence was 62.2% and associated with ≤high school diploma/GED (aPR, 1.08 [95% CI, 1.02-1.15]), sharing injection equipment (aPR, 1.08 [95% CI, 1.02-1.15]), high injection frequency (aPR, 1.16 [95% CI, 1.01-1.34]), and injecting speedball (aPR, 1.09 [95% CI, 1.01-1.16]).

CONCLUSIONS

Anti-HCV prevalence is high among PWID and varies with age. Scaling up direct-acting antiviral treatment, syringe service programs, and medication-assisted therapy is critical to mitigating transmission risk and infection burden.

Hepatitis B and C virus infections transmitted through organ transplantation investigated by CDC, United States, 2014-2017

We evaluated clinical outcomes among organ recipients with donor-derived hepatitis B virus (HBV) or hepatitis C virus (HCV) infections investigated by CDC from 2014 to 2017 in the United States. We characterized new HBV infections in organ recipients if donors tested negative for total anti-HBc, HBsAg and HBV DNA, and new recipient HCV infections if donors tested negative for anti-HCV and HCV RNA. Donor risk behaviors were abstracted from next-of-kin interviews and medical records. During 2014-2017, seven new recipient HBV infections associated with seven donors were identified; six (86%) recipients survived. At last follow-up, all survivors had functioning grafts and five (83%) had started antiviral therapy. Twenty new recipient HCV infections associated with nine donors were identified; 19 (95%) recipients survived. At last follow-up, 18 (95%) survivors had functioning grafts and 14 (74%) had started antiviral treatment. Combining donor next-of kin interviews and medical records, 11/16 (69%) donors had evidence of injection drug use and all met Public Health Service increased risk donor (IRD) criteria. IRD designation led to early diagnosis of recipient infection, and prompt implementation of therapy, likely reducing the risk of graft failure, liver disease, and death.

Prevalence and correlates of condom use among sexually active men who have sex with men in the United States: findings from the National Survey of Family Growth, 2002, 2006-10 and 2011-13

BACKGROUND

Men who have sex with men (MSM) are disproportionately at risk of contracting HIV and other sexually transmissible infections (STIs). Correct and consistent condom use is the most effective method to prevent HIV and other STIs among sexually active MSM.

METHODS

Using data from the 2002, 2006-10, 2011-13 cycles of the National Survey of Family Growth (NSFG), the overall prevalence of condom use at last sex and by sexual risk behaviours (sex with ≥2 same-sex partners, sex with ≥2 opposite sex partners, sex with a person who injects drugs, sex with an HIV-positive person and exchanged sex for money or drugs) among sexually active MSM (reported oral or anal sex with a male in the preceding 12 months) was estimated. The association between condom use at last sex and demographic and sexual behaviour variables was also evaluated.

RESULTS

Approximately 31% of all respondents (n=618; weighted n=1596702) reported condom use at last sex. Among MSM who reported ≥1 sexual risk behaviour in the past year, prevalence of condom use at last sex ranged from 30 to 38%. After adjusting for covariates, Hispanic MSM [adjusted prevalence ratio (APR)=1.81, 95%CI=1.27-2.58] were more likely than White MSM to report condom use at last sex; MSM with a recently diagnosed STI (APR=1.71, 95%CI=1.04-2.80) were more likely than MSM without a recently diagnosed STI to report condom use at last sex; and married or cohabitating MSM (APR=0.29, 95%CI=0.13-0.66) were less likely than unmarried and not cohabitating MSM to report condom use at last sex. There was no difference in temporal trends in condom use at last sex across the three NSFG cycles [2002 (33.8%); 2006-10 (25.6%); 2011-13 (40.6%), P=0.926].

CONCLUSIONS

This study data suggest that prevalence of condom use among MSM is low, even among MSM who report sexual risk behaviours. The continued promotion of consistent condom use as an effective primary HIV/STI risk-reduction strategy is important because it mitigates HIV and STI risk and also complements the effectiveness of newer HIV prevention approaches such as pre-exposure prophylaxis.

Association between trends in county-level opioid prescribing and reported rates of gonorrhea cases in the United States

PURPOSE

We investigated the association between county-level trends in opioid prescribing rates, a proxy for opioid misuse, and rates of reported gonorrhea (GC) among males in the United States.

METHODS

We used linear mixed-model regression analyses to evaluate the association between county-level trends in opioid prescribing rates and rates of reported GC among males during 2010-2015.

RESULTS

There was a positive association between trends in county-level opioid prescribing rates and rates of GC among males (β = 0.068, 95% confidence interval [CI] = 0.030, 0.105) during 2010-2015. However, the magnitude of this association decreased significantly over time in counties where opioid prescribing rates decreased (β = -0.018, 95% CI = -0.030, -0.006) and remained stable (β = -0.020, 95% CI = -0.038, -0.002) but was unchanged in counties where opioid prescribing rates increased (β = -0.029, 95% CI = -0.058, 0.001).

CONCLUSIONS

During 2010-2015, we found a positive association between increases in county-level opioid prescribing rates, a proxy for opioid misuse, and rates of reported GC among males especially in counties most affected by the opioid crisis. Integrating sexual health with opioid misuse interventions might be beneficial in addressing the GC burden in the United States.

Prenatal Screening for and Prevalence of Hepatitis B Surface Antigen in Pregnant Women and Prevention of Transmission to Infants Born to Infected Mothers-Guam, 2014

BACKGROUND

Perinatal transmission is the major mode of hepatitis B virus (HBV) transmission and drives HBV endemicity in the US territory of Guam. We assessed correlates of prenatal hepatitis B surface antigen (HBsAg) screening and HBsAg positivity among pregnant women and evaluated the care of infants of HBsAg-positive women.

METHODS

Demographic and clinical data were abstracted from the maternal medical records of 966 randomly selected live infants born in 2014. Frequencies were calculated, and prevalence ratios (PRs) and 95% confidence intervals (CIs) were estimated using Poisson regression.

RESULTS

Among the mothers of the 966 infants, 78.2% were Pacific Islanders, 56.9% were >25 years old (born before universal infant hepatitis B vaccination in Guam), 89.0% received prenatal care (PNC), 96.7% underwent prenatal HBsAg screening, and 2.0% were HBsAg positive. Approximately 15% of the women who did not have PNC were not screened for HBsAg. Receipt of PNC was associated with HBsAg screening (adjusted PR, 1.13 [95% CI, 1.04-1.23]), and HBsAg positivity was associated with a maternal age of >25 years (adjusted PR, 6.80 [95% CI, 1.32-35.08]). All 18 infants of the HBsAg-positive mothers received hepatitis B vaccine, and 17 (94.4%) received hepatitis B immunoglobulin.

CONCLUSION

Although the prenatal HBsAg screening prevalence in this sample was high, the maternal HBsAg prevalence among women in this sample was more than 14 times and 2 times the prevalence among US-born Pacific Islander/Asian women and all women in the continental United States, respectively. Improving access to PNC, ensuring that all pregnant women in Guam (especially those born before universal hepatitis B vaccination) are screened for HBsAg, and adopting postexposure prophylaxis for infants of HBsAg-positive mothers as standard clinical practice are important for preventing perinatal HBV transmission and reducing HBV endemicity.

The Predictive Value of International Classification of Disease Codes for Chronic Hepatitis C Virus Infection Surveillance: The Utility and Limitations of Electronic Health Records

Surveillance of chronic hepatitis C virus (HCV) cases faces limitations that result in delays and under-reporting. With increasing use of electronic health records (EHRs), the authors evaluated the predictive value of using International Classification of Diseases, Ninth Revision (ICD-9) codes to identify chronic HCV cases from EHR data. Longitudinal EHR data from 4 health care systems during 2006-2012 were evaluated. Using chart abstraction and review to confirm chronic HCV cases ("gold standard" definition), the authors calculated the sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of 2 case definitions: (1) ≥2 ICD-9 codes separated by ≥6 months and (2) ≥1 positive HCV RNA (ribonucleic acid) test. Among 2,718,995 patients, 20,779 (0.8%) with ICD-9 codes indicating a likely diagnosis of chronic HCV infection were identified; 13,595 (65.4%) of these were randomly selected for review. Case definition 1 (≥2 ICD-9 codes separated by ≥6 months) had 70.3% sensitivity, 91.9% PPV, 99.9% specificity, and 99.9% NPV while case definition 2 (≥1 positive HCV RNA test) had 74.1% sensitivity, 97.4% PPV, 99.9% specificity, and 99.9% NPV. The predictive values of these alternate EHR-derived ICD-9 code-based case definitions suggest that these measures may be useful in capturing the burden of diagnosed chronic HCV infections. Their use can augment current chronic HCV case surveillance efforts; however, their accuracy may vary by length of observation and completeness of EHR data.

Hepatitis B Vaccination, Screening, and Linkage to Care: Best Practice Advice From the American College of Physicians and the Centers for Disease Control and Prevention

BACKGROUND

Vaccination, screening, and linkage to care can reduce the burden of chronic hepatitis B virus (HBV) infection. However, recommendations vary among organizations, and their implementation has been suboptimal. The American College of Physicians' High Value Care Task Force and the Centers for Disease Control and Prevention developed this article to present best practice statements for hepatitis B vaccination, screening, and linkage to care.

METHODS

A narrative literature review of clinical guidelines, systematic reviews, randomized trials, and intervention studies on hepatitis B vaccination, screening, and linkage to care published between January 2005 and June 2017 was conducted.

BEST PRACTICE ADVICE 1

Clinicians should vaccinate against hepatitis B virus (HBV) in all unvaccinated adults (including pregnant women) at risk for infection due to sexual, percutaneous, or mucosal exposure; health care and public safety workers at risk for blood exposure; adults with chronic liver disease, end-stage renal disease (including hemodialysis patients), or HIV infection; travelers to HBV-endemic regions; and adults seeking protection from HBV infection.

BEST PRACTICE ADVICE 2

Clinicians should screen (hepatitis B surface antigen, antibody to hepatitis B core antigen, and antibody to hepatitis B surface antigen) for HBV in high-risk persons, including persons born in countries with 2% or higher HBV prevalence, men who have sex with men, persons who inject drugs, HIV-positive persons, household and sexual contacts of HBV-infected persons, persons requiring immunosuppressive therapy, persons with end-stage renal disease (including hemodialysis patients), blood and tissue donors, persons infected with hepatitis C virus, persons with elevated alanine aminotransferase levels (≥19 IU/L for women and ≥30 IU/L for men), incarcerated persons, pregnant women, and infants born to HBV-infected mothers.

BEST PRACTICE ADVICE 3

Clinicians should provide or refer all patients identified with HBV (HBsAg-positive) for posttest counseling and hepatitis B-directed care.

Correlates of Never Testing for HIV Among Non-Hispanic Black Men in the United States: National Survey of Family Growth, 2011-2013

Currently, the Centers for Disease Control and Prevention recommends that persons between 15 and 64 years get tested for human immunodeficiency virus (HIV) at least once in their lifetime and persons with HIV risk factors get tested more frequently. There is limited research examining factors associated with never testing for HIV among non-Hispanic Black men in the United States. The purpose of this study was to examine the prevalence of never testing for HIV, reasons for never testing for HIV, and correlates of never testing for HIV. We analyzed 2011-2013 National Survey of Family Growth data and restricted analyses to male respondents aged 15-44 years who self-identified as being non-Hispanic Black. Logistic regression models estimated adjusted prevalence ratios (APR) assessing the association between socio-demographic and behavioral factors and never testing for HIV. An estimated 31.2 % of non-Hispanic Black males aged 15-44 years have never been tested for HIV. Non-Hispanic Black men aged 15-17 years (APR 4.45; 95 % CI 2.88-6.87) or 18-24 years (APR 1.94; 95 % CI 1.21-3.13), who did not visit a doctor or healthcare provider (APR 1.43; 95 % CI 1.10-1.86), or did not report any sexual risk behaviors in the past 12 months (APR 1.83; 95 % CI 1.34-2.51) were more likely to never test for HIV compared to their respective counterparts. Continued expansion of HIV testing initiatives and prevention programs that focus on non-Hispanic Black men is critical to addressing HIV-related health disparities and the public health burden of HIV in this population.

Adherence to combination antiretroviral treatment and clinical outcomes in a Medicaid sample of older HIV-infected adults

The adherence threshold for combination antiretroviral therapy (cART) has historically been set at 95% or greater. We examined whether different levels of cART adherence (≥95% [optimal adherence], 90-94%, 80-89%, and <80%) were associated with different clinical outcomes (emergency department visits [ED visits] and duration of hospital admission) in a sample of older (50-64 years) persons living with HIV (PLWH). Medicaid data from 29 US states (n = 5177) were used for this study. cART adherence was measured and data regarding relevant covariates, such as race, sex, age, urbanicity, and comorbidity were obtained. Descriptive statistics were conducted to characterize study participants. We conducted univariate and multivariable regression analyses to evaluate the association between cART adherence and ED visits and duration of hospital admission while adjusting for covariates (race, sex, age, urbanicity, and comorbidity). Approximately 32% of all participants (n = 5177) reported optimal cART adherence (≥95%). After adjusting for covariates, only participants who reported <80% adherence were more likely to have an ED visit (adjusted odds ratio = 1.34, 95% CI = 1.08-1.48, p < .0001) and a longer duration of hospital admission (regression coefficient = 1.24, 95% CI = 0.53-1.96, p = .0007) when compared to participants who reported ≥95% adherence. There were no significant differences in likelihood of having an ED visit and longer duration of hospital admission between participants who reported ≥95% adherence and participants who reported 90-94% adherence and 80-89% adherence. Significant differences by covariates were observed. Adverse clinical outcomes were associated with low cART adherence (<80%) among older PLWH, though they did not differ between optimal and moderate cART adherence (90-94% and 80-89%). Although optimal cART adherence is an important goal, clinical outcomes in older PLWH may not differ between moderate and optimal cART adherence.

Correlates of Combination Antiretroviral Adherence Among Recently Diagnosed Older HIV-Infected Adults Between 50 and 64 years

Optimal adherence to combination antiretroviral therapy is essential to the health of older people living with HIV (PLWH), however, the literature on adherence and aging is limited. Using Medicaid data from 29 states (N = 5177), we explored correlates of optimal adherence among older PLWH. The prevalence of optimal adherence was low (32 %) in this study. Males were more adherent than females (APR = 1.11, 95 % CI 1.02-1.21, P = 0.0127); persons with three or more co-morbidities (APR = 0.67, 95 % CI 0.60-0.74, P < 0.001), two co-morbidities (APR = 0.86, 95 % CI 0.75-0.98, P = 0.0319) and one co-morbidity (APR = 0.82, 95 % CI 0.73-0.92, P = 0.0008) were less adherent than those without any co-morbidity; and residents of rural areas (APR = 0.90, 95 % CI 0.63-0.98, P = 0.0385) and small metropolitan areas (APR = 0.82, 95 % CI 0.72-0.94, P = 0.0032) were less adherent than residents of large metropolitan areas. There were no racial differences in optimal adherence. Targeted interventions that provide adherence support, case management, and peer navigation services may be of benefit in achieving optimal adherence in this population.

HIV Screening Rates among Medicaid Enrollees Diagnosed with Other Sexually Transmitted Infections

Introduction

Approximately 20 million new sexually transmitted infections (STIs) are diagnosed yearly in the United States costing the healthcare system an estimated $16 billion in direct medical expenses. The presence of other STIs increases the risk of HIV transmission. The Centers for Disease Control and Prevention (CDC) has long recommended routine HIV screening for individuals with a diagnosed STI. Unfortunately, HIV screening prevalence among STI diagnosed patients are still sub-optimal in many healthcare settings.

Objective

To determine the proportion of STI-diagnosed persons in the Medicaid population who are screened for HIV, examine correlates of HIV screening, and to suggest critical intervention points to increase HIV screening in this population.

Methods

A retrospective database analysis was conducted to examine the prevalence and correlates of HIV screening among participants. Participant eligibility was restricted to Medicaid enrollees in 29 states with a primary STI diagnosis (chlamydia, gonorrhea, and syphilis) or pelvic inflammatory disease claim in 2009. HIV-positive persons were excluded from the study. Frequencies and descriptive statistics were conducted to characterize the sample in general and by STI diagnosis. Univariate and multivariate logistic regression were performed to estimate unadjusted odds ratios and adjusted odds ratio respectively and the 95% confidence intervals. Multivariate logistic regression models that included the independent variables (race, STI diagnosis, and healthcare setting) and covariates (gender, residential status, age, and state) were analyzed to examine independent associations with HIV screening.

Results

About 43% of all STI-diagnosed study participants were screened for HIV. STI-diagnosed persons that were between 20–24 years, female, residing in a large metropolitan area and with a syphilis diagnosis were more likely to be screened for HIV. Participants who received their STI diagnosis in the emergency department were less likely to be screened for HIV than those diagnosed in a physician’s office.

Conclusion

This study showed that HIV screening prevalence among persons diagnosed with an STI are lower than expected based on the CDC’s recommendations. These suboptimal HIV screening prevalence present “missed opportunities” for HIV screening in at-risk populations. Measures and incentives to increase HIV screening among all STI-diagnosed persons are vital to the timely identification of HIV infection, linkage to HIV care, and mitigating further HIV transmission.

Syphilis Trends among Men Who Have Sex with Men in the United States and Western Europe: A Systematic Review of Trend Studies Published between 2004 and 2015

Globally, men who have sex with men (MSM) are disproportionately burdened with syphilis. This review describes the published literature on trends in syphilis infections among MSM in the US and Western Europe from 1998, the period with the fewest syphilis infections in both geographical areas, onwards. We also describe disparities in syphilis trends among various sub-populations of MSM. We searched electronic databases (Medline, Embase, Global Health, PsychInfo, CAB Abstracts, CINAHL, Sociological Abstracts, Web of Science, Cochrane Library, and LILACS) for peer-reviewed journal articles that were published between January 2004 and June 2015 and reported on syphilis cases among MSM at multiple time points from 1998 onwards. Ten articles (12 syphilis trend studies/reports) from the US and eight articles (12 syphilis trend studies/reports) from Western Europe were identified and included in this review. Taken together, our findings indicate an increase in the numbers and rates (per 100,000) of syphilis infections among MSM in the US and Western Europe since 1998. Disparities in the syphilis trends among MSM were also noted, with greater increases observed among HIV-positive MSM than HIV-negative MSM in both the US and Western Europe. In the US, racial minority MSM and MSM between 20 and 29 years accounted for the greatest increases in syphilis infections over time whereas White MSM accounted for most syphilis infections over time in Western Europe. Multiple strategies, including strengthening and targeting current syphilis screening and testing programs, and the prompt treatment of syphilis cases are warranted to address the increase in syphilis infections among all MSM in the US and Western Europe, but particularly among HIV-infected MSM, racial minority MSM, and young MSM in the US.

The association between combination antiretroviral adherence and AIDS-defining conditions at HIV diagnosis

Combination antiretroviral therapy (cART) has changed the clinical course of HIV. AIDS-defining conditions (ADC) are suggestive of severe or advanced disease and are a leading cause of HIV-related hospitalizations and death among people living with HIV/AIDS (PLWHA) in the USA. Optimal adherence to cART can mitigate the impact of ADC and disease severity on the health and survivability of PLWHA. The objective of this study was to evaluate the association between ADC at HIV diagnosis and optimal adherence among PLWHA. Using data from the 2008 and 2009 Medicaid data from 29 states, we identified individuals, between 18 and 49 years, recently infected with HIV and with a cART prescription. Frequencies and descriptive statistics were conducted to characterize sample. Univariate and multivariable Poisson regression analyses were employed to evaluate the association optimal cART adherence (defined as ≥ 95% study days covered by cART) and ADC at HIV diagnosis (≥1 ADC) were assessed. Approximately 17% of respondents with ADC at HIV diagnosis reported optimal cART adherence. After adjusting for covariates, respondents with an ADC at HIV diagnosis were less likely to report optimal cART adherence (adjusted prevalence ratio (APR) = 0.64, 95% confidence intervals (CI), 0.54-0.75). Among the covariates, males (APR=1.10, 95% CI, 1.02-1.19) compared to females were significantly more likely to report optimal adherence while younger respondents, 18-29 years (APR=0.67, 95% CI, 0.57-0.77), 30-39 years (APR=0.86, 95% CI, 0.79-0.95) compared to older respondents were significantly less likely to report optimal adherence. PLWHA with ADC at HIV diagnosis are at risk of suboptimal cART adherence. Multiple adherence strategies that include healthcare providers, case managers, and peer navigators should be utilized to improve cART adherence and optimize health outcomes among PLWHA with ADC at HIV diagnosis. Targeted adherence programs and services are required to address suboptimal adherence in this population.

HIV epidemic and human rights among men who have sex with men in sub-Saharan Africa: Implications for HIV prevention, care, and surveillance

Recent research has presented evidence that men who have sex with men (MSM) bear a disproportionate burden of HIV and are at increased risk for HIV in sub-Saharan Africa (SSA). However, many countries in SSA have failed to address the needs of MSM in national HIV/AIDS programmes. Furthermore, many MSM face structural barriers to HIV prevention and care, the most significant of which include laws that criminalise male-to-male sexual contact and facilitate stigma and discrimination. This in turn increases the vulnerability of MSM to acquiring HIV and presents barriers to HIV prevention, care, and surveillance. This relationship illustrates the link between human rights, social justice, and health outcomes and presents considerable challenges to addressing the HIV epidemic among MSM in SSA. The response to the HIV epidemic in SSA requires a non-discriminatory human rights approach to all at-risk groups, including MSM. Existing international human rights treaties, to which many SSA countries are signatories, and a 'health in all policies' approach provides a strong basis to reduce structural barriers to HIV prevention, care, surveillance, and research, and to ensure that all populations in SSA, including MSM, have access to the full range of rights that help ensure equal opportunities for health and wellness.

The influence of race and comorbidity on the timely initiation of antiretroviral therapy among older persons living with HIV/AIDS

OBJECTIVES

We examined whether the timely initiation of antiretroviral therapy (ART) differed by race and comorbidity among older (≥ 50 years) people living with HIV/AIDS (PLWHA).

METHODS

We conducted frequency and descriptive statistics analysis to characterize our sample, which we drew from 2005-2007 Medicaid claims data from 14 states. We employed univariate and multivariable Cox regression analyses to evaluate the relationship between race, comorbidity, and timely ART initiation (≤ 90 days post-HIV/AIDS diagnosis).

RESULTS

Approximately half of the participants did not commence ART promptly. After we adjusted for covariates, we found that older PLWHA who reported a comorbidity were 40% (95% confidence interval = 0.26, 0.61) as likely to commence ART promptly. We found no racial differences in the timely initiation of ART among older PLWHA.

CONCLUSIONS

Comorbidities affect timely ART initiation in older PLWHA. Older PLWHA may benefit from integrating and coordinating HIV care with care for other comorbidities and the development of ART treatment guidelines specific to older PLWHA. Consistent Medicaid coverage helps ensure consistent access to HIV treatment and care and may eliminate racial disparities in timely ART initiation among older PLWHA.

Improving Our Ability to Evaluate Underlying Mechanisms of Behavioral Onset and Other Event Occurrence Outcomes: A Discrete-Time Survival Mediation Model

The purpose of this article is to introduce and describe a statistical model that researchers can use to evaluate underlying mechanisms of behavioral onset and other event occurrence outcomes. Specifically, the article develops a framework for estimating mediation effects with outcomes measured in discrete-time epochs by integrating the statistical mediation model with discrete-time survival analysis. The methodology has the potential to help strengthen health research by targeting prevention and intervention work more effectively as well as by improving our understanding of discretized periods of risk. The model is applied to an existing longitudinal data set to demonstrate its use, and programming code is provided to facilitate its implementation.