Quantitative Methods Used to Evaluate Impact of Combination HIV Prevention Intervention: A Methodological Systematic Review.

Combination HIV prevention aims to provide the right mix of biomedical, behavioral and structural interventions, and is considered the best approach to curb the HIV pandemic. The impact evaluation of combined HIV prevention intervention (CHPI) provides critical information for decision making. We conducted a systematic review of the literature to map the designs and methods used in these studies. We searched original articles indexed in Web of Science, Scopus and PubMed. Fifty-eight studies assessing the impact of CHPI on HIV transmission were included. Most of the studies took place in Asia or sub-Saharan Africa and were published from 2000 onward. We identified 36 (62.1%) quasi-experimental studies (posttest, pretest-posttest and nonequivalent group designs) and 22 (37.9%) experimental studies (randomized designs). The findings suggest that diverse methods are already rooted in CHPI impact evaluation practices as recommended but should be better reported. CHPI impact evaluation would benefit from more comprehensive approaches.

Cost-effectiveness of strategies to control the spread of carbapenemase-producing Enterobacterales in hospitals: a modelling study.

BACKGROUND: Spread of resistant bacteria causes severe morbidity and mortality. Stringent control measures can be expensive and disrupt hospital organization. In the present study, we assessed the effectiveness and cost-effectiveness of control strategies to prevent the spread of Carbapenemase-producing Enterobacterales (CPE) in a general hospital ward (GW). METHODS: A dynamic, stochastic model simulated the transmission of CPE by the hands of healthcare workers (HCWs) and the environment in a hypothetical 25-bed GW. Input parameters were based on published data; we assumed the prevalence at admission of 0.1%. 12 strategies were compared to the baseline (no control) and combined different prevention and control interventions: targeted or universal screening at admission (TS or US), contact precautions (CP), isolation in a single room, dedicated nursing staff (DNS) for carriers and weekly screening of contact patients (WSC). Time horizon was one year. Outcomes were the number of CPE acquisitions, costs, and incremental cost-effectiveness ratios (ICER). A hospital perspective was adopted to estimate costs, which included laboratory costs, single room, contact precautions, staff time, i.e. infection control nurse and/or dedicated nursing staff, and lost bed-days due to prolonged hospital stay of identified carriers. The model was calibrated on actual datasets. Sensitivity analyses were performed. RESULTS: The baseline scenario resulted in 0.93 CPE acquisitions/1000 admissions and costs 32,050 €/1000 admissions. All control strategies increased costs and improved the outcome. The efficiency frontier was represented by: (1) TS with DNS at a 17,407 €/avoided CPE case, (2) TS + DNS + WSC at a 30,700 €/avoided CPE case and (3) US + DNS + WSC at 181,472 €/avoided CPE case. Other strategies were dominated. Sensitivity analyses showed that TS + CP might be cost-effective if CPE carriers are identified upon admission or if the cases have a short hospital stay. However, CP were effective only when high level of compliance with hand hygiene was obtained. CONCLUSIONS: Targeted screening at admission combined with DNS for identified CPE carriers with or without weekly screening were the most cost-effective options to limit the spread of CPE. These results support current recommendations from several high-income countries.

Quantitative methods used to evaluate impact of health promotion interventions to prevent HIV infections: a methodological systematic review protocol.

BACKGROUND: Combination prevention is currently considered the best approach to combat HIV epidemic. It is based upon the combination of structural, behavioral, and biomedical interventions. Such interventions are frequently implemented in a health-promoting manner due to their aims, the approach that was adopted, and their complexity. The impact evaluation of these interventions often relies on methods inherited from the biomedical field. However, these methods have limitations and should be adapted to be relevant for these complex interventions. This systematic review aims to map the evidence-based methods used to quantify the impact of these interventions and analyze how these methods are implemented. METHODS: Three databases (Web of Science, Scopus, PubMed) will be used to identify impact evaluation studies of health promotion interventions that aimed at reducing the incidence or prevalence of HIV infection. Only studies based on quantitative design assessing intervention impact on HIV prevalence or incidence will be included. Two reviewers will independently screen studies based on titles and abstracts and then on the full text. The information about study characteristics will be extracted to understand the context in which the interventions are implemented. The information specific to quantitative methods of impact evaluation will be extracted using items from the Mixed Methods Appraisal Tool (MMAT), the guidelines for reporting Statistical Analyses and Methods in the Published Literature (SAMPL), and the guidelines for Strengthening The Reporting of Empirical Simulation Studies (STRESS). This review will be conducted according to the Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) statement. DISCUSSION: The impact evaluation of HIV prevention interventions is a matter of substantial importance given the growing need for evidence of the effectiveness of these interventions, whereas they are increasingly complex. These evaluations allow to identify the most effective strategies to be implemented to fight the epidemic. It is therefore relevant to map the methods to better implement them and adapt them according to the type of intervention to be evaluated. SYSTEMATIC REVIEW REGISTRATION: PROSPERO CRD42020210825.

Hand hygiene improvement or antibiotic restriction to control the household transmission of extended-spectrum ß-lactamase-producing Escherichia coli: a mathematical modelling study.

BACKGROUND: The best strategy to control ESBL-producing Escherichia coli (ESBL-EC) spread in the community is lacking. METHODS: We developed an individual-based transmission model to evaluate the impact of hand hygiene (HH) improvement and reduction in antibiotic use on the within-household transmission of ESBL-EC. We used data from the literature and incorporated key elements of ESBL-EC transmission such as the frequency and nature of contacts among household members, antibiotic use in the community and hand hygiene behaviour. We introduced in a household a single ESBL-EC colonised person and simulated the transmission dynamics of ESBL-EC over a one-year time horizon. RESULTS: The probability of ESBL-EC transmission depended on the household composition and the profile of the initial carrier. In the two-person household, the probability of ESBL-EC transmission was 5.3% (95% CI 5.0-5.6) or 6.6% (6.3-6.9) when the index person was a woman or a man, respectively. In a four-person household, the probability of transmission varied from 61.4% (60.9-62.0) to 68.8% (68.3-69.3) and was the highest when the index patient was the baby. Improving HH by 50% reduced the probability of transmission by 33-62%. Antibiotic restriction by 50% reduced the transmission by 2-6%. CONCLUSIONS: The transmission of ESBL-EC is frequent in households and especially those with a baby. Antibiotic reduction had little impact on ESBL-EC. Improvement of hygiene in the community could help prevent transmission of ESBL-EC.

Universal or targeted approach to prevent the transmission of extended-spectrum beta-lactamase-producing Enterobacteriaceae in intensive care units: a cost-effectiveness analysis.

OBJECTIVE: Several control strategies have been used to limit the transmission of multidrug-resistant organisms in hospitals. However, their implementation is expensive and effectiveness of interventions for the control of extended-spectrum beta-lactamase-producing Enterobacteriaceae (ESBL-PE) spread is controversial. Here, we aim to assess the cost-effectiveness of hospital-based strategies to prevent ESBL-PE transmission and infections. DESIGN: Cost-effectiveness analysis based on dynamic, stochastic transmission model over a 1-year time horizon. PATIENTS AND SETTING: Patients hospitalised in a hypothetical 10-bed intensive care unit (ICU) in a high-income country. INTERVENTIONS: Base case scenario compared with (1) universal strategies (eg, improvement of hand hygiene (HH) among healthcare workers, antibiotic stewardship), (2) targeted strategies (eg, screening of patient for ESBL-PE at ICU admission and contact precautions or cohorting of carriers) and (3) mixed strategies (eg, targeted approaches combined with antibiotic stewardship). MAIN OUTCOMES AND MEASURES: Cases of ESBL-PE transmission, infections, cost of intervention, cost of infections, incremental cost per infection avoided. RESULTS: In the base case scenario, 15 transmissions and five infections due to ESBL-PE occurred per 100 ICU admissions, representing a mean cost of €94 792. All control strategies improved health outcomes and reduced costs associated with ESBL-PE infections. The overall costs (cost of intervention and infections) were the lowest for HH compliance improvement from 55%/60% before/after contact with a patient to 80%/80%. CONCLUSIONS: Improved compliance with HH was the most cost-saving strategy to prevent the transmission of ESBL-PE. Antibiotic stewardship was not cost-effective. However, adding antibiotic restriction strategy to HH or screening and cohorting strategies slightly improved their effectiveness and may be worthy of consideration by decision-makers.

Hand Hygiene, Cohorting, or Antibiotic Restriction to Control Outbreaks of Multidrug-Resistant Enterobacteriaceae.

BACKGROUND: The best strategy for controlling extended-spectrum ß-lactamase-producing Enterobacteriaceae (ESBL-PE) transmission in intensive care units (ICUs) remains elusive. OBJECTIVE: We developed a stochastic transmission model to quantify the effectiveness of interventions aimed at reducing the spread of ESBL-PE in an ICU. METHODS: We modeled the evolution of an outbreak caused by the admission of a single carrier in a 10-bed ICU free of ESBL-PE. Using data obtained from recent muticenter studies, we studied 26 strategies combining different levels of the following 3 interventions: (1) increasing healthcare worker compliance with hand hygiene before and after contact with a patient; (2) cohorting; (3) reducing antibiotic prevalence at admission with or without reducing antibiotherapy duration. RESULTS: Improving hand hygiene compliance from 55% before patient contact and 60% after patient contact to 80% before and 80% after patient contact reduced the nosocomial incidence rate of ESBL-PE colonization by 91% at 90 days. Adding cohorting to hand hygiene improvement intervention decreased the proportion of ESBL-PE acquisitions by an additional 7%. Antibiotic restriction had the lowest impact on the epidemic. When combined with other interventions, it only marginally improved effectiveness, despite strong hypotheses regarding antibiotic impact on transmission. CONCLUSION: Our results suggest that hand hygiene is the most effective intervention to control ESBL-PE transmission in an ICU.

Antibiotic reduction campaigns do not necessarily decrease bacterial resistance: the example of methicillin-resistant Staphylococcus aureus.

Interventions designed to reduce antibiotic consumption are under way worldwide. While overall reductions are often achieved, their impact on the selection of antibiotic-resistant selection cannot be assessed accurately from currently available data. We developed a mathematical model of methicillin-sensitive and methicillin-resistant Staphylococcus aureus (MSSA and MRSA) transmission inside and outside the hospital. A systematic simulation study was then conducted with two objectives: to assess the impact of antibiotic class-specific changes during an antibiotic reduction period and to investigate the interactions between antibiotic prescription changes in the hospital and the community. The model reproduced the overall reduction in MRSA frequency in French intensive-care units (ICUs) with antibiotic consumption in France from 2002 to 2003 as an input. However, the change in MRSA frequency depended on which antibiotic classes changed the most, with the same overall 10% reduction in antibiotic use over 1 year leading to anywhere between a 69% decrease and a 52% increase in MRSA frequency in ICUs and anywhere between a 37% decrease and a 46% increase in the community. Furthermore, some combinations of antibiotic prescription changes in the hospital and the community could act in a synergistic or antagonistic way with regard to overall MRSA selection. This study shows that class-specific changes in antibiotic use, rather than overall reductions, need to be considered in order to properly anticipate the impact of an antibiotic reduction campaign. It also highlights the fact that optimal gains will be obtained by coordinating interventions in hospitals and in the community, since the effect of an intervention in a given setting may be strongly affected by exogenous factors.

Impact of antibiotic exposure patterns on selection of community-associated methicillin-resistant Staphylococcus aureus in hospital settings.

Community-associated methicillin-resistant S. aureus (CA-MRSA) is increasingly common in hospitals, with potentially serious consequences. The aim of this study was to assess the impact of antibiotic prescription patterns on the selection of CA-MRSA within hospitals, in a context of competition with other circulating staphylococcal strains, including methicillin-sensitive (MSSA) and hospital-associated methicillin-resistant (HA-MRSA) strains. We developed a computerized agent-based model of S. aureus transmission in a hospital ward in which CA-MRSA, MSSA, and HA-MRSA strains may cocirculate. We investigated a wide range of antibiotic prescription patterns in both intensive care units (ICUs) and general wards, and we studied how differences in antibiotic exposure may explain observed variations in the success of CA-MRSA invasion in the hospitals of several European countries and of the United States. Model predictions underlined the influence of antibiotic prescription patterns on CA-MRSA spread in hospitals, especially in the ICU, where the endemic prevalence of CA-MRSA carriage can range from 3% to 20%, depending on the simulated prescription pattern. Large antibiotic exposure with drugs effective against MSSA but not MRSA was found to promote invasion by CA-MRSA. We also found that, should CA-MRSA acquire fluoroquinolone resistance, a major increase in CA-MRSA prevalence could ensue in hospitals worldwide. Controlling the spread of highly community-prevalent CA-MRSA within hospitals is a challenge. This study demonstrates that antibiotic exposure strategies could participate in this control. This is all the more important in wards such as ICUs, which may play the role of incubators, promoting CA-MRSA selection in hospitals.