Impact of Regulatory Post-Market Safety Advisories on Prescribing Practices: An Interrupted Time Series Analysis

Less frequent adverse drug reactions are usually discovered after a drug's release to the market, making effective and timely communication of regulatory post-market advisories essential for preventing emerging adverse effects. Time series analysis is a key study design for assessing the impact of post-market safety advisories. However, most previous studies have focused on narrow evaluations, limiting systematic assessment of how different safety advisories affect prescribing practices. This study aimed to investigate changes in prescribing practices following regulatory post-market safety advisories in Korea. Interrupted time series analyses were conducted using nationwide claims data from 2018 to 2021 and hospital datasets covering the period from 2 years before and 3 years after post-market safety advisories. We categorized the selected drugs into two groups: safety warning through letters and real-time safety alarms (contraindications or requiring attention). Twelve post-market safety advisories were analyzed, including four safety warnings and eight safety alarms, which showed an overall relative reduction (safety warning: relative change [95% confidence interval]: -8.06% [-10.23% to -5.84%], safety alarm on contraindication: -92.65% [-95.65% to -87.59%], and safety alarm on requiring attention: -8.04% [-9.98% to -6.05%]). All types of regulatory interventions reduced the prescribing of targeted drugs; however, the magnitude of these effects differed substantially depending on the type of intervention. By identifying and comparing the influence of regulatory post-market safety advisories, we can enhance these measures to better protect patient health. Continuous monitoring and systematic assessment of safety-related regulatory advisories, with ensured reproducibility, are warranted to optimize effectiveness and ensure safe medication practices.

The impact of a comprehensive strategy on HIV treatment continuum in a highly endemic area of China: an interrupted time series analysis

BACKGROUND

A comprehensive strategy encompassing universal testing and strengthened treatment was promoted to address the severe HIV epidemic in Liangshan. This study aimed to assess the impact of this strategy on HIV treatment continuum.

METHODS

Interrupted time series (ITS) analysis was utilized to evaluate the impact of a comprehensive strategy on HIV treatment outcomes in Liangshan from 2014 to 2021 utilizing data from China's HIV/AIDS Comprehensive Response Information Management System (CRIMS). Poisson or quasi-Poisson segmented regression models were applied to estimate the trends and immediate changes in key outcomes, including the proportion of 30-day antiretroviral therapy (ART) initiation, the proportion of 6-month follow-up, and the proportion of viral suppression, following the strategy's implementation in January 2018. The analysis was stratified by sex, age, transmission route, and region, with areas classified as key areas and non-key areas based on an HIV prevalence threshold of 1%.

RESULTS

A total of 37,888 people living with HIV (PLHIV) were identified during the study period, with an increase in diagnoses following comprehensive strategy implementation. Most cases involved males, aged 15-34 years, residents of key areas, and individuals infected through heterosexual transmission. There was a significant increase of 2.50-fold in 30-day ART initiation (incidence rate ratio [IRR] 2.501, 95% CI: 1.694-3.694), 34.0% in 6-month follow-up (1.340, 95% CI: 1.234-1.456), and 17.7% in viral suppression (1.177, 95% CI: 1.068-1.296) in the first month of comprehensive strategy implementation. Over time, all three indicators displayed an upward trend, and by December 2021, their predicted values significantly increased, exceeding the expected levels by 60.3% (IRR 1.603, 95% CI: 1.108-2.318), 62.9% (1.629, 95% CI: 1.430-1.855), and 50.6% (1.506, 95% CI: 1.223-1.855), respectively. Subgroup analysis revealed that while the strategy's effects on these outcomes were generally consistent, the magnitude of improvement varied. Residents of key areas exhibited more significant increases in 30-day ART initiation, while residents of non-key areas, particularly those aged ≥ 60 years, displayed smaller increases in the proportion of 6-month follow-up, and no significant change in the proportion of viral suppression, with a slightly lower average.

CONCLUSIONS

The implementation of a comprehensive strategy substantially improved timely ART initiation, follow-up care after ART and viral suppression for PLHIV in Liangshan, with consistent enhancements across various subpopulations. It is imperative to strengthen comprehensive strategy in non-key areas of Liangshan, and to promote these strategies in other similar regions in order to enhance health benefits for patients.

Impact of increasing CD4 count threshold eligibility for antiretroviral therapy initiation on advanced HIV disease and tuberculosis prevalence and incidence in South Africa: an interrupted time series analysis

INTRODUCTION

We investigated the impact of increasing CD4 count eligibility for antiretroviral therapy (ART) initiation on advanced HIV disease (AHD) and tuberculosis (TB) prevalence and incidence among people living with HIV (PLHIV) in South Africa.

METHODS

We conducted an interrupted time series analysis with de-identified data of PLHIV aged ≥15 years initiating ART between April 2012 and February 2020 at 65 primary healthcare clinics in KwaZulu-Natal, South Africa. Outcomes included monthly proportions of new ART initiators presenting with AHD (CD4 count <200 cells/µL) and TB disease. We created a cohort of monthly ART initiators without TB and evaluated the cumulative incidence of TB within 12 months follow-up. We used segmented binomial regression models to estimate relative risks (RR) of outcomes, allowing for a step and slope change after expanding the ART initiation CD4 count eligibility from <350 to <500 cells/µL in January 2015 and following Universal Test and Treat (UTT) implementation in September 2016.

RESULTS

Among 209 984 participants, median age was 32 (range: 26-38), and 141 499 (67.4%) were female. After January 2015, the risk of AHD at initiation decreased in step by 25.0% (RR=0.750, 95% CI 0.688 to 0.812) and further reduced by 26.9% following UTT implementation (RR=0.731, 95% CI 0.681 to 0.781). The risk of TB at initiation also decreased in step by 27.6% after January 2015 (RR=0.724, 95% CI 0.651 to 0.797) and further decreased by 17.4% after UTT implementation (RR=0.826, 95% CI 0.711 to 0.941) but remained stable among initiators with AHD. Among the incidence cohort, we saw a step decrease in the risk of new TB by 31.4% (RR=0.686, 95% CI 0.465 to 0.907) following UTT implementation. Among the incidence cohort with AHD, there was weak evidence of a step decrease in the risk of new TB (RR=0.755, 95% CI 0.489 to 1.021), but the slope decreased by 9.7% per month (RR=0.903, 95% CI 0.872 to 0.934) following UTT implementation.

CONCLUSIONS

Our data support the added benefit of decreased TB co-burden with expanded ART access. Early diagnosis and immediate linkage to care should be prioritised among PLHIV.

Impact of Mobile Health (mHealth) Use by Community Health Workers on the Utilization of Maternity Care in Rural Malawi: A Time Series Analysis

Purpose

Maternal mortality in Malawi is high, with low coverage of maternity care being a contributing factor. To improve maternal health coverage, an Android-based, integrated mobile health (mHealth) app called YendaNafe was introduced to community health workers (CHWs) in the Neno district, rural Malawi. This study evaluates the impact of this app on the uptake of antenatal care (ANC), facility-based births, and postnatal care (PNC), compared to a reference period where CHWs provided the same services without mHealth, using the interrupted time series analysis.

Patients and Methods

Using aggregated monthly data and segmented quasi-Poisson regression models, we compared the effects of mHealth on selected maternal health outcomes. The models were adjusted for the COVID-19 pandemic, the occurrence of cyclones, and a cholera epidemic. We analyzed data from six eligible health facilities and their respective catchment areas in which CHWs were using YendaNafe, and compared 12 months before and 12 months after its introduction.

Results

The use of YendaNafe was associated with a 22% immediate increase in facility-based births (aIRR 1.22, 95% CI 1.12-1.33, p<0.001) but not an immediate increase in new ANC visits (aIRR 1.02,95% CI 0.90-1.14, p=0.77), ANC in the first trimester (aIRR 1.17, 95% CI 0.95-1.45 p=0.13), or PNC visits (aIRR 1.03, 95% CI 0.79-1.36, p=0.81). For long-term effect, YendaNafe was associated with an increase in new ANC visits (aIRR 1.04, 95% CI 1.01-1.07, p <0.01) and ANC in the first trimester (aIRR 1.03,95% CI 1.00-1.07 p=0.046), but not facility-based births (aIRR 1.01, 95% CI 0.99-1.03, p=0.46) or PNC (aIRR 0.97 95% CI 0.93-1.01, p=0.14).

Conclusion

mHealth shows potential of increasing utilization of new ANC visits, ANC in the first trimester and facility-based births. Further research is needed to understand why mHealth did not have an effect on PNC.

The impact of the Covid-19 pandemic on work accidents with exposure to biological material in Brazil: an interrupted time series analysis

OBJECTIVE

To analyze the impact of the Covid-19 pandemic on the occurrence of work accidents involving biological materials (ATBio) and to assess changes in the epidemiological profile of these cases.

METHODS

An ecological time-series study with a cross-sectional component was conducted using ATBio notifications in Brazil from 2015 to 2022 in the Information System for Notifiable Diseases (Sinan). Interrupted time-series analyses were performed using Prais-Winsten regression models, temporal predictions, and multiple logistic regression to identify changes in the profile between the pandemic and pre-pandemic periods.

RESULTS

A total of 499,916 ATBio cases were recorded between 2015 and 2022, with an increasing trend from 2015 to 2019. During the first year of the pandemic, 57,731 (11.5%) accidents were reported, with an estimated reduction of 791.8 ATBio notifications per month during this period. There was a change in the accident profile, with a higher occurrence of ATBio during the first year of the pandemic among workers with 1 to 8 and 9 to 11 years of education, and a lower occurrence among pregnant women. There was also a higher occurrence of exposure to non-categorized biological materials, increased use of masks and face shields, and higher post-accident seroconversion rates.

CONCLUSION

The occurrence of ATBio was impacted by the Covid-19 pandemic, leading to a reduction in notifications and a change in the event profile on a national scale.

The associations of supervised consumption services with the rates of opioid-related mortality and morbidity outcomes at the public health unit level in Ontario (Canada): A controlled interrupted time-series analysis

INTRODUCTION

This study aimed to assess the impact of the implementation of legally sanctioned supervised consumption sites (SCS) in the Canadian province of Ontario on opioid-related deaths, emergency department (ED) visits and hospitalisations at the public health unit (PHU) level.

METHODS

Monthly rates per 100,000 population of opioid-related deaths, ED visits and hospitalisations for PHUs in Ontario between December 2013 and March 2022 were collected. Aggregated and individual analyses of PHUs with one or more SCS were conducted, with PHUs that instituted an SCS being matched to control units that did not. Autoregressive integrated moving average models were used to estimate the impact of SCS implementation on opioid-related deaths, ED visits and hospitalisations.

RESULTS

Twenty-one legally sanctioned SCS were implemented across nine PHUs in Ontario during the study period. Interrupted time series analyses showed no statistically significant changes in opioid-related death rates in aggregated analyses of intervention PHUs (increase of 0.02 deaths/100,000 population/month; p = 0.27). Control PHUs saw a significant increase of 0.38 deaths/100,000 population/month; p < 0.001. No statistically significant changes were observed in the rates of opioid-related ED visits in intervention PHUs (decrease of 0.61 visits/100,000 population/month; p = 0.39) or controls (increase of 0.403 visits; p = 0.76). No statistically significant changes to the rates of opioid-related hospitalisations were observed in intervention PHUs (0 hospitalisations/100,000 population/month; p = 0.98) or controls (decrease of 0.05 hospitalisations; p = 0.95).

DISCUSSION AND CONCLUSIONS

This study did not find significant mortality or morbidity effects associated with SCS availability at the population level in Ontario. In the context of a highly toxic drug supply, additional interventions will be required to reduce opioid-related harms.

The impact of COVID-19 restrictions on HIV prevention and treatment services for key populations in South Africa: an interrupted time series analysis

BACKGROUND

Key populations (KP), including men who have sex with men (MSM), female sex workers (FSW), and transgender women (TGW), experience a disproportionate burden of HIV, even in generalized epidemics like South Africa. Given this disproportionate burden and unique barriers to accessing health services, sustained provision of care is particularly relevant. It is unclear how the COVID-19 pandemic and its associated restrictions may have impacted this delivery. In this study, we aimed to describe patterns of engagement in HIV prevention and treatment services among KP in South Africa and assess the impact of different COVID-19 restriction levels on service delivery.

METHODS

We leveraged programmatic data collected by the US President's Emergency Plan for AIDS Relief (PEPFAR)-supported KP partners in South Africa. We divided data into three discrete time periods based on national COVID-19 restriction periods: (i) Pre-restriction period, (ii) High-level restriction period, and (iii) After-high level restriction period. Primary outcomes included monthly total HIV tests, new HIV cases identified, new initiations of pre-exposure prophylaxis (PrEP), and new enrollments in antiretroviral therapy (ART). We conducted interrupted time series segmented regression analyses to estimate the impact of COVID-19 restrictions on HIV prevention and treatment service utilization.

RESULTS

Between January 2018 and June 2022, there were a total of 231,086 HIV tests, 27,051 HIV positive cases, 27,656 pre-exposure prophylaxis (PrEP) initiations, and 15,949 antiretroviral therapy initiations among MSM, FSW and TGW in PEPFAR-supported KP programs in South Africa. We recorded 90,457 total HIV tests during the 'pre-restriction' period, with 13,593 confirmed new HIV diagnoses; 26,134 total HIV tests with 2,771 new diagnoses during the 'high-level restriction' period; and 114,495 HIV tests with 10,687 new diagnoses during the after high-level restriction period. Our Poisson regression model estimates indicate an immediate and significant decrease in service engagement at the onset of COVID-19 restrictions, including declines in HIV testing, treatment, and PrEP use, which persisted. As programs adjusted to the new restrictions, there was a gradual rebound in service engagement, particularly among MSM and FSW. Towards the end of the high-level restriction period, with some aspects of daily life returning to normal but others still restricted, there was more variability. Some indicators continued to improve, while others stagnated or decreased.

CONCLUSION

Service provision rebounded from the initial shock created by pandemic-related restrictions, and HIV services were largely maintained for KP in South Africa. These results suggest that HIV service delivery among programs designed for KP was able to be flexible and resilient to the evolving restrictions. The results of this study can inform plans for future pandemics and large-scale disruptions to the delivery of HIV services.

The effect of a minimum price per unit of alcohol in Scotland on alcohol-related ambulance call-outs: A controlled interrupted time-series analysis

BACKGROUND AND AIMS

On 1 May 2018, Scotland introduced a minimum unit price (MUP) of £0.50 for alcohol, with one UK unit of alcohol being 10 ml of pure ethanol. This study measured the association between MUP and changes in the volume of alcohol-related ambulance call-outs in the overall population and in call-outs subsets (night-time call-outs and subpopulations with higher incidence of alcohol-related harm).

DESIGN

An interrupted time-series (ITS) was used to measure variations in the daily volume of alcohol-related call-outs. We performed uncontrolled ITS on both the intervention and control group and a controlled ITS built on the difference between the two series. Data were from electronic patient clinical records from the Scottish Ambulance Service.

SETTING AND CASES

Alcohol-related ambulance call-outs (intervention group) and total ambulance call-outs for people aged under 13 years (control group) in Scotland, from December 2017 to March 2020.

MEASUREMENTS

Call-outs were deemed alcohol-related if ambulance clinicians indicated that alcohol was a 'contributing factor' in the call-out and/or a validated Scottish Ambulance Service algorithm determined that the call-out was alcohol-related.

FINDINGS

No statistically significant association in the volume of call-outs was found in both the uncontrolled series [step change = 0.062, 95% confidence interval (CI) = -0.012, 0.0135 P = 0.091; slope change = -0.001, 95% CI = -0.001, 0.1 × 10-3 P = 0.139] and controlled series (step change = -0.01, 95% CI = -0.317, 0.298 P = 0.951; slope change = -0.003, 95% CI = -0.008, 0.002 P = 0.257). Similarly, no significant changes were found for the night-time series or for any population subgroups.

CONCLUSIONS

There appears to be no statistically significant association between the introduction of minimum unit pricing for alcohol in Scotland and the volume of alcohol-related ambulance call-outs. This was observed overall, across subpopulations and at night-time.

Impact of COVID-19 pandemic on depression incidence and healthcare service use among patients with depression: an interrupted time-series analysis from a 9-year population-based study

BACKGROUND

Most studies on the impact of the COVID-19 pandemic on depression burden focused on the earlier pandemic phase specific to lockdowns, but the longer-term impact of the pandemic is less well-studied. In this population-based cohort study, we examined the short-term and long-term impacts of COVID-19 on depression incidence and healthcare service use among patients with depression.

METHODS

Using the territory-wide electronic medical records in Hong Kong, we identified all patients aged ≥ 10 years with new diagnoses of depression from 2014 to 2022. We performed an interrupted time-series (ITS) analysis to examine changes in incidence of medically attended depression before and during the pandemic. We then divided all patients into nine cohorts based on year of depression incidence and studied their initial and ongoing service use patterns until the end of 2022. We applied generalized linear modeling to compare the rates of healthcare service use in the year of diagnosis between patients newly diagnosed before and during the pandemic. A separate ITS analysis explored the pandemic impact on the ongoing service use among prevalent patients with depression.

RESULTS

We found an immediate increase in depression incidence (RR = 1.21, 95% CI: 1.10-1.33, p < 0.001) in the population after the pandemic began with non-significant slope change, suggesting a sustained effect until the end of 2022. Subgroup analysis showed that the increases in incidence were significant among adults and the older population, but not adolescents. Depression patients newly diagnosed during the pandemic used 11% fewer resources than the pre-pandemic patients in the first diagnosis year. Pre-existing depression patients also had an immediate decrease of 16% in overall all-cause service use since the pandemic, with a positive slope change indicating a gradual rebound over a 3-year period.

CONCLUSIONS

During the pandemic, service provision for depression was suboptimal in the face of increased demand generated by the increasing depression incidence during the COVID-19 pandemic. Our findings indicate the need to improve mental health resource planning preparedness for future public health crises.

Design and statistical analysis reporting among interrupted time series studies in drug utilization research: a cross-sectional survey

INTRODUCTION

Interrupted time series (ITS) design is a commonly used method for evaluating large-scale interventions in clinical practice or public health. However, improperly using this method can lead to biased results.

OBJECTIVE

To investigate design and statistical analysis characteristics of drug utilization studies using ITS design, and give recommendations for improvements.

METHODS

A literature search was conducted based on PubMed from January 2021 to December 2021. We included original articles that used ITS design to investigate drug utilization without restriction on study population or outcome types. A structured, pilot-tested questionnaire was developed to extract information regarding study characteristics and details about design and statistical analysis.

RESULTS

We included 153 eligible studies. Among those, 28.1% (43/153) clearly explained the rationale for using the ITS design and 13.7% (21/153) clarified the rationale of using the specified ITS model structure. One hundred and forty-nine studies used aggregated data to do ITS analysis, and 20.8% (31/149) clarified the rationale for the number of time points. The consideration of autocorrelation, non-stationary and seasonality was often lacking among those studies, and only 14 studies mentioned all of three methodological issues. Missing data was mentioned in 31 studies. Only 39.22% (60/153) reported the regression models, while 15 studies gave the incorrect interpretation of level change due to time parameterization. Time-varying participant characteristics were considered in 24 studies. In 97 studies containing hierarchical data, 23 studies clarified the heterogeneity among clusters and used statistical methods to address this issue.

CONCLUSION

The quality of design and statistical analyses in ITS studies for drug utilization remains unsatisfactory. Three emerging methodological issues warranted particular attention, including incorrect interpretation of level change due to time parameterization, time-varying participant characteristics and hierarchical data analysis. We offered specific recommendations about the design, analysis and reporting of the ITS study.

Evaluating the impact of minimum unit pricing for alcohol on road traffic accidents in Scotland after 20 months: An interrupted time series study

BACKGROUND AND AIMS

On 1 May 2018, Scotland implemented Minimum Unit Pricing (MUP) of £0.50 per unit of alcohol with the aim to lower alcohol consumption and related harms, and reduce health inequalities. We measured the impact of MUP on the most likely categories of road traffic accidents (RTAs) to be affected by drink-driving episodes (fatal and nighttime) up to 20 months after the policy implementation. Further, we checked whether any association varied by level of socio-economic deprivation.

METHODS

An interrupted time series design was used to evaluate the impact of MUP on fatal and nighttime RTAs in Scotland and any effect modification across socio-economic deprivation groups. RTAs in England and Wales (E&W) were used as a comparator. Covariates representing severe weather events, bank holidays, seasonal and underlying trends were adjusted for.

RESULTS

In Scotland, MUP implementation was associated with 40.5% (95% confidence interval: 15.5%, 65.4%) and 11.4% (-1.1%, 24.0%) increases in fatal and nighttime RTAs, respectively. There was no evidence of differential impacts of MUP by level of socio-economic deprivation. While we found a substantial increase in fatal RTAs associated with MUP, null effects observed in nighttime RTAs and high uncertainty in sensitivity analyses suggest caution be applied before attributing causation to this association.

CONCLUSION

There is no evidence of an association between the introduction of minimum unit pricing for alcohol in Scotland and a reduction in fatal and nighttime road traffic accidents, these being outcome measure categories that are proxies of outcomes that directly relate alcohol consumption to road traffic accidents.

Assessing the impact and implications of the revised Act on the Aggravated Punishment of Specific Crimes in preventing child traffic injuries in school zones in Korea: an interrupted time series analysis

In 2019, a child's death in Korea led to legislation that imposed stricter penalties for school zone traffic violations. We assessed the impact of that legislation using 2017-2022 Traffic Accident Analysis System data. Adjusted analyses revealed a significant decline in severe injuries in school zones, decreasing from 11 cases to 8 cases per month (p=0.017). The legislation correlated with a reduced risk of all child traffic injuries (risk ratio, 0.987; 95% confidence interval, 0.977 to 0.997; p=0.002), indicating its efficacy in curbing accidents.

Evaluation of a Targeted COVID-19 Community Outreach Intervention: Case Report for Precision Public Health

BACKGROUND

Cameron County, a low-income south Texas-Mexico border county marked by severe health disparities, was consistently among the top counties with the highest COVID-19 mortality in Texas at the onset of the pandemic. The disparity in COVID-19 burden within Texas counties revealed the need for effective interventions to address the specific needs of local health departments and their communities. Publicly available COVID-19 surveillance data were not sufficiently timely or granular to deliver such targeted interventions. An agency-academic collaboration in Cameron used novel geographic information science methods to produce granular COVID-19 surveillance data. These data were used to strategically target an educational outreach intervention named "Boots on the Ground" (BOG) in the City of Brownsville (COB).

OBJECTIVE

This study aimed to evaluate the impact of a spatially targeted community intervention on daily COVID-19 test counts.

METHODS

The agency-academic collaboration between the COB and UTHealth Houston led to the creation of weekly COVID-19 epidemiological reports at the census tract level. These reports guided the selection of census tracts to deliver targeted BOG between April 21 and June 8, 2020. Recordkeeping of the targeted BOG tracts and the intervention dates, along with COVID-19 daily testing counts per census tract, provided data for intervention evaluation. An interrupted time series design was used to evaluate the impact on COVID-19 test counts 2 weeks before and after targeted BOG. A piecewise Poisson regression analysis was used to quantify the slope (sustained) and intercept (immediate) change between pre- and post-BOG COVID-19 daily test count trends. Additional analysis of COB tracts that did not receive targeted BOG was conducted for comparison purposes.

RESULTS

During the intervention period, 18 of the 48 COB census tracts received targeted BOG. Among these, a significant change in the slope between pre- and post-BOG daily test counts was observed in 5 tracts, 80% (n=4) of which had a positive slope change. A positive slope change implied a significant increase in daily COVID-19 test counts 2 weeks after targeted BOG compared to the testing trend observed 2 weeks before intervention. In an additional analysis of the 30 census tracts that did not receive targeted BOG, significant slope changes were observed in 10 tracts, of which positive slope changes were only observed in 20% (n=2). In summary, we found that BOG-targeted tracts had mostly positive daily COVID-19 test count slope changes, whereas untargeted tracts had mostly negative daily COVID-19 test count slope changes.

CONCLUSIONS

Evaluation of spatially targeted community interventions is necessary to strengthen the evidence base of this important approach for local emergency preparedness. This report highlights how an academic-agency collaboration established and evaluated the impact of a real-time, targeted intervention delivering precision public health to a small community.

Effect of immunization registry-based provider reminder to initiate HPV vaccination at age 9, Washington state

Human papillomavirus (HPV) vaccination rates are lower than Tetanus-diphtheria-pertussis (Tdap) and Meningococcal conjugate (MenACWY) rates, although the Advisory Committee on Immunization Practices recommends all three vaccines be given routinely at age 11-12. Evidence is mounting that children who initiate HPV vaccination starting at age 9 are more likely to complete the series on time. Washington state implemented a provider reminder through its immunization information system (WAIIS) in January 2023 to increase HPV vaccine initiation at 9-years-old by updating the forecasted recommended age for HPV from age 11 to 9. The effectiveness of provider reminders when implemented via an immunization information system (IIS) is poorly understood. We evaluated the impact of this forecast update using a seasonally adjusted interrupted time series regression of weekly HPV initiations at 9-years-old before and after implementation. We also examined time series trends of vaccine administration between 2018 and 2023 for HPV initiation at age 9, as well as Tdap, MenACWY and HPV initiation at age 11. The WAIIS forecast update doubled the weekly rate of HPV initiation among 9-year-olds in Washington state, although the weekly count of initiation at 9 remains far lower than initiations at 11. Jurisdictions wanting to increase HPV vaccine initiation at earlier ages should consider updating their forecast algorithm and investing in complementary evidence-based strategies such as provider and parent education, and clinic-based quality improvement efforts. The reach of IIS forecaster updates may be enhanced by working with administrators of electronic medical record systems to ensure parity of provider prompts with IIS.

Impact of active case-finding for tuberculosis on case-notifications in Blantyre, Malawi: A community-based cluster-randomised trial (SCALE)

Active case-finding (ACF) for tuberculosis can help find the "missing millions" with undiagnosed tuberculosis. In a cluster-randomised trial, we investigated impact of ACF on case-notifications in Blantyre, Malawi, where ACF has been intensively implemented following 2014 estimates of ~1,000 per 100,000 adults with undiagnosed TB. Following a pre-intervention prevalence survey (May 2019 to March 2020), constrained randomisation allocated neighbourhoods to either door-to-door ACF (sputum microscopy for reported cough >2 weeks) or standard-of-care (SOC). Implementation was interrupted by COVID-19. Cluster-level bacteriologically-confirmed case-notification rate (CNR) ratio within 91 days of ACF was our redefined primary outcome; comparison between arms used Poisson regression with random effects. Secondary outcomes were 91-day CNR ratios comparing all tuberculosis registrations and all non-ACF registrations. Interrupted time series (ITS) analysis of CNRs in the SOC arm examined prevalence survey impact. (ISRCTN11400592). 72 clusters served by 10 study-supported tuberculosis registration centres were randomised to ACF (261,244 adults, 58,944 person-years follow-up) or SOC (256,713 adults, 52,805 person-years). Of 1,192 ACF participants, 13 (1.09%) were smear-positive. Within 91 days, 113 (42 bacteriologically-confirmed) and 108 (33 bacteriologically-confirmed) tuberculosis patients were identified as ACF or SOC cluster residents, respectively. There was no difference by arm, with adjusted 91-day CNR ratios 1.12 (95% CI: 0.61-2.07) for bacteriologically-confirmed tuberculosis; 0.93 (95% CI: 0.68-1.28) for all tuberculosis registrations; and 0.86 (95%CI: 0.63-1.16) for non-ACF (routinely) diagnosed. Of 7,905 ACF and 7,992 SOC pre-intervention survey participants, 12 (0.15%) and 17 (0.21%), respectively, had culture/Xpert-confirmed tuberculosis. ITS analysis showed no survey impact on SOC CNRs. Despite residual undiagnosed tuberculosis of 150 per 100,000 population, there was no increase in tuberculosis notifications from this previously successful approach targeting symptomatic disease, likely due to previous TB ACF and rapid declines in TB burden. In such settings, future ACF should focus on targeted outreach and demand creation, alongside optimised facility-based screening. Trial Registration: ISRCTN11400592.

The road to recovery: impact of COVID-19 on healthcare utilization in South Korea in 2016-2022 using an interrupted time-series analysis

Background

The COVID-19 pandemic substantially disrupted healthcare utilization patterns, globally. South Korea had been praised widely in its efforts to contain the spread of the pandemic, which may have contributed to a significantly smaller reduction in healthcare utilization compared to neighboring countries. However, it remains unknown how the COVID-19 pandemic impacted utilization patterns across population sub-groups, particularly vulnerable patient groups in South Korea. This paper quantifies the changes in healthcare utilization attributable to COVID-19 and the COVID-19 vaccination by sub-groups.

Methods

An interrupted time series analysis was conducted to examine the impact of COVID-19 on healthcare utilization in South Korea from January 2016 to December 2022 using aggregated patient-level data from the national health insurance system that accounts for 99% of all healthcare services in South Korea. We applied negative binomial models adjusting for seasonality and serial correlation. Falsification tests were conducted to test the validity of breakpoints. Stratified analyses by type of healthcare services, age, sex, income level, health facility type, and avoidable/non-avoidable hospitalizations was performed, and we assessed differences in utilization trends between population groups across three phases of the pandemic.

Findings

In early 2020, the COVID-19 pandemic caused a reduction in monthly volume of outpatient utilization by 15.7% [95% CI 13.3%-18.1%, p < 0.001] and inpatient utilization by 11.6% [10.1%-13.0%, p < 0.001]. Most utilization recovered and rebounded to pre-COVID-19 levels as of December 2022 although variations existed. We observed heterogeneity in the magnitude of relative changes in utilization across types of services, varying from a 42.7% [36.8%-48.0%, p < 0.001] decrease for pediatrics, a 23.4% [20.1%-26.5%%, p < 0.001] reduction in utilization of public health centers, and a 24.2% [21.2%-27.0%, p < 0.001] reduction in avoidable hospitalizations compared to the pre-pandemic period. Contrary to global trends, health utilization among the elderly population (65 and older) in South Korea saw only marginal reductions compared to other age groups. Similarly, Medicaid patients and lower income groups experienced a smaller reduction compared to higher income groups.

Interpretation

The impact of the COVID-19 pandemic on healthcare utilization in South Korea was less pronounced compared to the global average. Utilization of vulnerable populations, including adults over 65 years old and lowest-income groups reduced less than other type of patients.

Funding

No funding.

Interrupted time series evaluation of the impact of a dementia wellbeing service on avoidable hospital admissions for people with dementia in Bristol, England

OBJECTIVES

To determine whether a dementia wellbeing service (DWS) signposting people with dementia to community services decreases the rate of avoidable hospital admissions, in-hospital mortality, complexity of admissions (number of comorbidities) or length of stay.

METHODS

Interrupted time series analysis to estimate the effects of the DWS on hospital outcomes. We included all unplanned admissions for ambulatory care sensitive conditions ('avoidable hospital admissions') with a dementia diagnosis recorded in the Hospital Episode Statistics. The intervention region was compared with a demographically similar control region in the 2 years before and 3 years after the implementation of the new service (October 2013 to September 2018).

RESULTS

There was no strong evidence that admission rates reduced and only weak evidence that the trend in average length of stay reduced slowly over time. In-hospital mortality decreased immediately after the introduction of the dementia wellbeing service compared to comparator areas (x0.64, 95% CI 0.42, 0.97, p = 0.037) but attenuated over the following years. The rate of increase in comorbidities also appeared to slow after the service began; they were similar to comparator areas by September 2018.

CONCLUSIONS

We found no major impact of the DWS on avoidable hospital admissions, although there was weak evidence for slightly shorter length of stay and reduced complexity of hospital admissions. These findings may or may not reflect a true benefit of the service and require further investigation. The DWS was established to improve quality of dementia care; reducing hospital admissions was never its sole purpose. More targeted interventions may be required to reduce hospital admissions for people with dementia.

Impact of COVID-19 pandemic on Tuberculosis and HIV services in Ghana: An interrupted time series analysis

INTRODUCTION

The Coronavirus disease 2019 (COVID-19) burden, coupled with unprecedented control measures including physical distancing, travel bans, and lockdowns of cities, implemented to stop the spread of the virus, have undoubtedly far-reaching aftereffects on other diseases. In low and middle-income countries (LMICs), a particular worry is the potential impact on Human Immunodeficiency Virus (HIV) and Tuberculosis (TB), as a consequence of possible disruption to health services and limiting access to needed life-saving health care. In Ghana, there is a paucity of information regarding the impact of COVID-19 on disease control, particularly TB and HIV control. This study sought to contribute to bridging this knowledge gap.

METHOD

The study involved the analysis of secondary data obtained from the District Health Information Management System-2 (DHIMS-2) database of Ghana Health Service, from 2016 to 2020. Data were analysed using an interrupted time-series regression approach to estimate the impact of COVID-19 on TB case notification, HIV testing, and Antiretroviral Therapy (ART) initiations, using March 2020 as the event period.

RESULTS

The study showed that during the COVID-19 pandemic period, there was an abrupt decline of 20.5% (955CI: 16.0%, 24.5%) in TB case notifications in April and 32.7% (95%CI: 28.8%, 39.1%) in May 2020, with a median monthly decline of 21.4% from April-December 2020. A cumulative loss of 2,128 (20%; 95%CI: 13.3%, 26.7%) TB cases was observed nationwide as of December 2020. There was also a 40.3% decrease in people presenting for HIV tests in the first month of COVID-19 (April 2020) and a cumulative loss of 262620 (26.5%) HIV tests as of December 2020 attributable to the COVID-19 pandemic. ART initiations increased by 39.2% in the first month and thereafter decreased by an average of 10% per month from May to September 2020. Cumulatively, 443 (1.9%) more of the people living with HIV initiated ART during the pandemic period, however, this was not statistically significant.

CONCLUSION

This study demonstrated that the COVID-19 pandemic negatively impacted TB case notifications and HIV testing and counselling services, However, ART initiation was generally not impacted during the first year of the pandemic. Proactive approaches aimed at actively finding the thousands of individuals with TB who were missed in 2020 and increasing HIV testing and counselling and subsequent treatment initiations should be prioritised.

Assessing the impact of the "malaria supporters project" intervention to malaria control in the Brazilian Amazon: an interrupted time-series analysis

BACKGROUND

In 2021, Brazil was responsible for more than 25% of malaria cases in the Americas. Although the country has shown a reduction of cases in the last decades, in 2021 it reported over 139,000 malaria cases. One major malaria control strategy implemented in Brazil is the "Malaria Supporters Project", which has been active since 2012 and is directed to municipalities responsible for most Brazil's cases. The objective of this study is to analyse the intervention effect on the selected municipalities.

METHODS

An ecological time-series analysis was conducted to assess the "Malaria Supporters Project" effect. The study used data on Annual Parasitic Incidence (API) spanning the period from 2003 to 2020 across 48 intervention municipalities and 88 control municipalities. To evaluate the intervention effect a Prais-Winsten segmented regression model was fitted to the difference in malaria Annual Parasitic Incidence (API) between control and intervention areas.

RESULTS

The intervention group registered 1,104,430 cases between 2012 and 2020, a 50.6% reduction compared to total cases between 2003 and 2011. In 2020 there were 95,621 cases, 50.4% fewer than in 2011. The number of high-risk municipalities (API > 50 cases/1000) reduced from 31 to 2011 to 17 in 2020. The segmented regression showed a significant 42.0 cases/1000 residents annual decrease in API compared to control group.

CONCLUSIONS

The intervention is not a silver bullet to control malaria, but it has reduced API in locations with high malaria endemicity. Furthermore, the model has the potential to be replicated in other countries with similar epidemiological scenarios.

Evaluating the Impact of the COVID-19-Related Public Health Restrictions on Access to Digital Sexually Transmitted and Blood-Borne Infection Testing in British Columbia, Canada: An Interrupted Time Series Analysis

BACKGROUND

Evidence of long-term impacts of COVID-19-related public health restrictions on digital sexually transmitted and blood-borne infection (STBBI) testing utilization is limited. We assessed these impacts on GetCheckedOnline (a digital testing resource for STBBIs) relative to all STBBI tests in British Columbia (BC).

METHODS

Interrupted time series analyses were conducted using GetCheckedOnline program data comparing monthly test episodes (STBBI tests per requisition) among BC residents, stratified by BC region, and testers' sociodemographic and sexual risk profiles, for the prepandemic (March 2018-February 2020) and pandemic periods (March 2020-October 2021). Trends in GetCheckedOnline testing per 100 STBBI tests in BC regions with GetCheckedOnline were analyzed. Each outcome was modeled using segmented generalized least squared regression.

RESULTS

Overall, 17,215 and 22,646 test episodes were conducted in the prepandemic and pandemic periods. Monthly GetCheckedOnline test episodes reduced immediately after restrictions. By October 2021 (end of the pandemic period), monthly GetCheckedOnline testing increased by 21.24 test episodes per million BC residents (95% confidence interval, -11.88 to 54.84), and GetCheckedOnline tests per 100 tests in corresponding BC regions increased by 1.10 (95% confidence interval, 0.02 to 2.17) above baseline trends. After initial increases among users at higher STBBI risk (symptomatic testers/testers reporting sexual contacts with STBBIs), testing decreased below baseline trends later in the pandemic, whereas monthly GetCheckedOnline testing increased among people 40 years or older, men who have sex with men, racialized minorities, and first-time testers via GetCheckedOnline.

CONCLUSIONS

Sustained increases in utilization of digital STBBI testing during the pandemic suggest fundamental changes in STBBI testing in BC, highlighting the need for accessible and appropriate digital testing, especially for those most affected by STBBIs.

Changes in human papillomavirus prevalence, incidence, and clearance among men who have sex with men in Xinjiang, China after implementation of nonpharmaceutical interventions to control COVID-19: An interrupted time series analysis

OBJECTIVES

This study aimed to assess the effects of COVID-19 nonpharmaceutical interventions (NPIs) on the human papillomavirus (HPV) epidemic among men who have sex with men (MSM) in Xinjiang, China.

METHODS

In our cohort study, we enrolled and followed HIV-negative MSM in Xinjiang, China, between 2016 and 2022. Anal swab samples were collected to test for HPV DNA. We used interrupted time series analysis to characterize the temporal trends in HPV prevalence, incidence, and clearance before (September 01, 2016, to July 16, 2020) and during the implementation of COVID-19 NPIs in Xinjiang (July 17, 2020, to March 31, 2022). We used binomial segmented regression models to estimate the impact of COVID-19 NPIs on HPV prevalence, incidence, and clearance.

RESULTS

We recruited 1296 MSM who contributed to a total of 5374 HPV tests in our study. COVID-19 NPIs were associated with a 37.9% decrease in the prevalence (prevalence ratio, 0.621; 95% confidence interval, 0.465-0.830), 52.2% decrease in the incidence (risk ratio, 0.478; 0.377-0.606), and 40.4% increase in the clearance (risk ratio, 1.404; 1.212-1.627) of HPV of any genotype after the implementation of COVID-19 NPIs in Xinjiang.

CONCLUSION

COVID-19 NPIs may lead to lower transmission and higher clearance of HPV among MSM. Future studies are needed to clarify the longer-term impact of COVID-19 on the transmission and natural history of HPV among MSM.

The effect of a comprehensive typhoid conjugate vaccine campaign on antimicrobial prescribing in children in Harare, Zimbabwe: a mixed methods study

BACKGROUND

Vaccines prevent infections and could subsequently reduce antimicrobial use. A 1-week mass vaccination campaign was done with Typbar-TCV (Bharat Biotech, Hyderabad, India) between Feb 25 and March 4, 2019. We investigated whether this typhoid conjugate vaccine campaign could affect antimicrobial prescribing in children presenting to primary care in Harare, Zimbabwe.

METHODS

In this mixed methods study, data for acute paediatric outpatient consultations between Jan 1, 2018, and March 31, 2020, were collected from five clinics in Harare. Interrupted time series analysis was done to compare prescription data before and after the campaign. To contextualise findings, qualitative data were collected between April 20, 2021, and July 20, 2022, comprising ethnographic research (ie, workshops, surveys, observations, and interviews) in 14 clinics. Ethnographic data were used for thematic analysis. The primary outcome was monthly antimicrobial prescriptions in children aged 6 months to 15 years, normalised by the number of trauma events in all age groups.

FINDINGS

In the data collection period, 27 107 paediatric consultations were recorded. 17 951 (66·2%) of 27 107 children were prescribed antimicrobials. Despite the perceived reduction in typhoid cases and a decreasing trend in the prescription of antimicrobials commonly used to treat typhoid (ie, ciprofloxacin and azithromycin), mass vaccination with Typbar-TCV did not affect the total rate of antimicrobials (adjusted rate ratio, 1·20, 95% CI 0·70-2·05, p=0·51) or the rate of typhoid antimicrobials prescribed (0·93, 0·44-1·96, p=0·85). Unsafe water sources and insufficient diagnostic services were reported to contribute to the continued disease burden and antimicrobial prescription.

INTERPRETATION

Non-specific febrile illness caused by confirmed or suspected typhoid is a common cause of antimicrobial use in endemic areas. Although effective in preventing typhoid fever, we were unable to identify any effect of Typbar-TCV on antimicrobial prescribing. Ethnographic research showed the effect of contextual factors on antimicrobial prescribing, including concerns regarding safe water access, appropriate sewage disposal, health-care and diagnostic availability. To realise effects beyond disease burden reduction, holistic approaches addressing these concerns are needed so that the value of vaccines mitigating the effects of antimicrobial use as a driver of antimicrobial resistance is fully achieved.

FUNDING

Wellcome Trust.

TRANSLATION

For the Shona translation of the abstract see Supplementary Materials section.

The COVID-19 green certificate's effect on vaccine uptake in French and Italian regions

The COVID-19 green certificates were introduced in many countries in 2021 to encourage vaccine uptake against the COVID-19 virus in order to reduce the spread of severe infection among the population, ensure the safety of cross-border movements, and facilitate the resumption of social life and economic activities. This study uses a single-group interrupted time series approach to examine the effect of the green certificate announcement on the first doses of the COVID-19 vaccine in 20 Italian and 18 French regions during the summer of 2021. The estimation results show that the green certificate announcement mitigated regional disparities in vaccine uptake. It persuaded undecided people to have their first doses of the COVID-19 vaccine, especially in regions lagging in the mass vaccination campaign. It was less effective in those regions where there was already a high level of vaccine protection. The announcement also proved to be an effective political strategy with which to increase the first-dose rates immediately, but not in the long term.

4CMenB sustained vaccine effectiveness against invasive meningococcal B disease and gonorrhoea at three years post program implementation

OBJECTIVES

To evaluate persistence of vaccine effectiveness (VE) and vaccine impact (VI) on invasive meningococcal B (MenB) disease and gonorrhoea at three years after implementation of a state funded 4CMenB program for infants, children, adolescents and young people in South Australia.

METHODS

VI was assessed using a Poisson or negative binomial regression model, and VE was estimated using screening and case-control methods. Chlamydia controls were used to estimate VE in the primary analysis to control potential confounding effects such as high-risk sexual behaviour associated with sexually transmitted infections.

RESULTS

During the three-year program, reductions of 63.1% (95%CI 29.0% to 80.9%) and 78.5% (95%CI 33.0% to 93.1%) in incidence of MenB disease were observed in infants and adolescents, respectively. There were no cases in infants who had received three doses of 4CMenB. Two-dose VE against MenB disease was 90.7% (95%CI 6.9% to 99.1%) for the childhood program and 83.5% (95%CI 0 to 98.2%) for the adolescent program. Two-dose VE against gonorrhoea in adolescents was 33.2% (95%CI 15.9% to 47.0%). Lower VE estimates were demonstrated after 36 months post-vaccination (23.2% (95%CI 0 to 47.5%) >36 months post-vaccination compared to 34.9% (95%CI 15.0% to 50.1%) within 6-36 months). Higher VE estimates were found after excluding patients with repeat gonorrhoea infections (37.3%, 95%CI 19.8% to 51.0%). For gonorrhoea cases co-infected with chlamydia VE was maintained (44.7% (95%CI 17.1% to 63.1%).

CONCLUSION

The third-year evaluation results show persistent vaccine effectiveness of 4CMenB against MenB disease in infants and adolescents. As this is the first ongoing program for adolescents, moderate vaccine protection against gonorrhoea with waning effectiveness three years post-vaccination was demonstrated in adolescents and young adults. The additional protection of 4CMenB vaccine against gonorrhoea, likely through cross-protection should be considered in cost-effectiveness analyses. A booster dose may need to be further evaluated and considered in adolescents due to waning protection against gonorrhoea demonstrated after 36 months post-vaccination.

The Effect of Minimum Unit Pricing for Alcohol on Prescriptions for Treatment of Alcohol Dependence: A Controlled Interrupted Time Series Analysis

In 2018, Scotland introduced a minimum unit price (MUP) for alcohol to reduce alcohol-related harms. We aimed to study the association between MUP introduction and the volume of prescriptions to treat alcohol dependence, and volume of new patients receiving such prescriptions. We also examined whether effects varied across different socio-economic groups. A controlled interrupted time series was used to examine variations of our two outcomes. The same prescriptions in England and prescriptions for methadone in Scotland were used as controls. There was no evidence of an association between MUP implementation and the volume of prescriptions for alcohol dependence (immediate change: 2.74%, 95% CI: -0.068 0.014; slope change: 0% 95%CI: -0.001 0.000). A small, significant increase in slope in number of new patients receiving prescriptions was observed (0.2% 95%CI: 0.001 0.003). However, no significant results were confirmed after robustness checks. We found also no variation across different socioeconomic groups.

Supplementary Information

The online version contains supplementary material available at 10.1007/s11469-023-01070-6.

Impact of pausing elective hip and knee replacement surgery during winter 2017 on subsequent service provision at a major NHS Trust: a descriptive observational study using interrupted time series

OBJECTIVES

To explore the impact of a temporary cancellation of elective surgery in winter 2017 on trends in primary hip and knee replacement at a major National Health Service (NHS) Trust, and whether lessons can be learnt about efficient surgery provision.

DESIGN AND SETTING

Observational descriptive study using interrupted time series analysis of hospital records to explore trends in primary hip and knee replacement surgery at a major NHS Trust, as well as patient characteristics, 2016-2019.

INTERVENTION

A temporary cancellation of elective services for 2 months in winter 2017.

OUTCOMES

NHS-funded hospital admissions for primary hip or knee replacement, length of stay and bed occupancy. Additionally, we explored the ratio of elective to emergency admissions at the Trust as a measure of elective capacity, and the ratio of public to private provision of NHS-funded hip and knee surgery.

RESULTS

After winter 2017, there was a sustained reduction in the number of knee replacements, a decrease in the proportion of most deprived people having knee replacements and an increase in average age for knee replacement and comorbidity for both types of surgery. The ratio of public to private provision dropped after winter 2017, and elective capacity generally has reduced over time. There was clear seasonality in provision of elective surgery, with less complex patients admitted during winter.

CONCLUSIONS

Declining elective capacity and seasonality has a marked effect on the provision of joint replacement, despite efficiency improvements in hospital treatment. The Trust has outsourced less complex patients to independent providers, and/or treated them during winter when capacity is most limited. There is a need to explore whether these are strategies that could be used explicitly to maximise the use of limited elective capacity, provide benefit to patients and value for money for taxpayers.

In praise of Prais-Winsten: An evaluation of methods used to account for autocorrelation in interrupted time series

Interrupted time series are increasingly being used to assess the population impact of public health interventions. These data are usually correlated over time (auto correlated) and this must be accounted for in the analysis. Typically, this is done using either the Prais-Winsten method, the Newey-West method, or autoregressive-moving-average (ARMA) modeling. In this paper, we illustrate these methods via a study of pneumococcal vaccine introduction and explore their performance under 20 simulated autocorrelation scenarios with sample sizes ranging between 20 and 300. We show that in terms of mean square error, the Prais-Winsten and ARMA methods perform best, while in terms of coverage the Prais-Winsten method generally performs better than other methods. All three methods are unbiased. As well as having good statistical properties, the Prais-Winsten method is attractive because it is decision-free and produces a single measure of autocorrelation that can be compared between studies and used to guide sample size calculations. We would therefore encourage analysts to consider using this simple method to analyze interrupted time series.

Clinical and Ecological Impact of an Educational Program to Optimize Antibiotic Treatments in Nursing Homes (PROA-SENIOR): A Cluster, Randomized, Controlled Trial and Interrupted Time-Series Analysis

BACKGROUND

Antimicrobial stewardship programs (ASPs) are recommended in nursing homes (NHs), although data are limited. We aimed to determine the clinical and ecological impact of an ASP for NHs.

METHODS

We performed a cluster, randomized, controlled trial and a before-after study with interrupted time-series analyses in 14 NHs for 30 consecutive months from July 2018 to December 2020 in Andalusia, Spain. Seven facilities implemented an ASP with a bundle of 5 educational measures (general ASP) and 7 added 1-to-1 educational interviews (experimental ASP). The primary outcome was the overall use of antimicrobials, calculated monthly as defined daily doses (DDD) per 1000 resident days (DRD).

RESULTS

The total mean antimicrobial consumption decreased by 31.2% (-16.72 DRD; P = .045) with respect to the preintervention period; the overall use of quinolones and amoxicillin-clavulanic acid dropped by 52.2% (P = .001) and 42.5% (P = .006), respectively; and the overall prevalence of multidrug-resistant organisms (MDROs) decreased from 24.7% to 17.4% (P = .012). During the intervention period, 12.5 educational interviews per doctor were performed in the experimental ASP group; no differences were found in the total mean antimicrobial use between groups (-14.62 DRD; P = .25). Two unexpected coronavirus disease 2019 waves affected the centers increasing the overall mean use of antimicrobials by 40% (51.56 DRD; P < .0001).

CONCLUSIONS

This study suggests that an ASP for NHs appears to be associated with a decrease in total consumption of antimicrobials and prevalence of MDROs. This trial did not find benefits associated with educational interviews, probably due to the coronavirus disease 2019 pandemic. Clinical Trials Registration. NCT03543605.

Influenza-Associated Excess Mortality by Age, Sex, and Subtype/Lineage: Population-Based Time-Series Study With a Distributed-Lag Nonlinear Model

BACKGROUND

Accurate estimation of the influenza death burden is of great significance for influenza prevention and control. However, few studies have considered the short-term harvesting effects of influenza on mortality when estimating influenza-associated excess deaths by cause of death, age, sex, and subtype/lineage.

OBJECTIVE

This study aimed to estimate the cause-, age-, and sex-specific excess mortality associated with influenza and its subtypes and lineages in Guangzhou from 2015 to 2018.

METHODS

Distributed-lag nonlinear models were fitted to estimate the excess mortality related to influenza subtypes or lineages for different causes of death, age groups, and sex based on daily time-series data for mortality, influenza, and meteorological factors.

RESULTS

A total of 199,777 death certificates were included in the study. The average annual influenza-associated excess mortality rate (EMR) was 25.06 (95% empirical CI [eCI] 19.85-30.16) per 100,000 persons; 7142 of 8791 (81.2%) deaths were due to respiratory or cardiovascular mortality (EMR 20.36, 95% eCI 16.75-23.74). Excess respiratory and cardiovascular deaths in people aged 60 to 79 years and those aged ≥80 years accounted for 32.9% (2346/7142) and 63.7% (4549/7142) of deaths, respectively. The male to female ratio (MFR) of excess death from respiratory diseases was 1.34 (95% CI 1.17-1.54), while the MFR for excess death from cardiovascular disease was 0.72 (95% CI 0.63-0.82). The average annual excess respiratory and cardiovascular mortality rates attributed to influenza A (H3N2), B/Yamagata, B/Victoria, and A (H1N1) were 8.47 (95% eCI 6.60-10.30), 5.81 (95% eCI 3.35-8.25), 3.68 (95% eCI 0.81-6.49), and 2.83 (95% eCI -1.26 to 6.71), respectively. Among these influenza subtypes/lineages, A (H3N2) had the highest excess respiratory and cardiovascular mortality rates for people aged 60 to 79 years (20.22, 95% eCI 14.56-25.63) and ≥80 years (180.15, 95% eCI 130.75-227.38), while younger people were more affected by A (H1N1), with an EMR of 1.29 (95% eCI 0.07-2.32). The mortality displacement of influenza A (H1N1), A (H3N2), and B/Yamagata was 2 to 5 days, but 5 to 13 days for B/Victoria.

CONCLUSIONS

Influenza was associated with substantial mortality in Guangzhou, occurring predominantly in the elderly, even after considering mortality displacement. The mortality burden of influenza B, particularly B/Yamagata, cannot be ignored. Contrasting sex differences were found in influenza-associated excess mortality from respiratory diseases and from cardiovascular diseases; the underlying mechanisms need to be investigated in future studies. Our findings can help us better understand the magnitude and time-course of the effect of influenza on mortality and inform targeted interventions for mitigating the influenza mortality burden, such as immunizations with quadrivalent vaccines (especially for older people), behavioral campaigns, and treatment strategies.

The impact of COVID-19 non-pharmaceutical interventions on HIV care continuum in China: An interrupted time series analysis

Background

China implemented strict non-pharmaceutical interventions to contain COVID-19 at the early stage. We aimed to evaluate the impact of COVID-19 on HIV care continuum in China.

Methods

Aggregated data on HIV care continuum between 1 January 2017 and 31 December 2020 were collected from centers for disease control and prevention at different levels and major infectious disease hospitals in various regions in China. We used interrupted time series analysis to characterize temporal trend in weekly numbers of HIV post-exposure prophylaxis (PEP) prescriptions, HIV tests, HIV diagnoses, median time intervals between HIV diagnosis and antiretroviral therapy (ART) initiation (time intervals, days), ART initiations, mean CD4+ T cell counts at ART initiation (CD4 counts, cells/μL), ART collections, and missed visits for ART collection, before and after the implementation of massive NPIs (23 January to 7 April 2020). We used Poisson segmented regression models to estimate the immediate and long-term impact of NPIs on these outcomes.

Findings

A total of 16,780 PEP prescriptions, 1,101,686 HIV tests, 69,659 HIV diagnoses, 63,409 time intervals and ART initiations, 61,518 CD4 counts, 1,528,802 ART collections, and 6656 missed visits were recorded during the study period. The majority of outcomes occurred in males (55·3-87·4%), 21-50 year olds (51·7-90·5%), Southwestern China (38·2-82·0%) and heterosexual transmission (47·9-66·1%). NPIs was associated with 71·5% decrease in PEP prescriptions (IRR 0·285; 95% CI 0·192-0·423), 36·1% decrease in HIV tests (0·639, 0·497-0·822), 32·0% decrease in HIV diagnoses (0·680, 0·511-0·904), 59·3% increase in time intervals (1·593, 1·270-1·997) and 17·4% decrease in CD4 counts (0·826, 0·746-0·915) in the first week during NPIs. There was no marked change in the number of ART initiations, ART collections and missed visits during the NPIs. By the end of 2020, the number of HIV tests, HIV diagnoses, time intervals, ART initiations, and CD4 counts reached expected levels, but the number of PEP prescriptions (0·523, 0·394-0·696), ART collections (0·720, 0·595-0·872), and missed visits (0·137, 0·086-0·220) were still below expected levels. With the ease of restrictions, PEP prescriptions (slope change 1·024/week, 1·012-1·037), HIV tests (1·016/week, 1·008-1·026), and CD4 counts (1·005/week, 1·001-1·009) showed a significant increasing trend.

Interpretation

HIV care continuum in China was affected by the COVID-19 NPIs at various levels. Preparedness and efforts to maintain the HIV care continuum during public health emergencies should leverage collaborations between stakeholders.

Funding

Natural Science Foundation of China.

The control of malaria vectors in rice fields: a systematic review and meta-analysis

The relatively stable aquatic conditions of irrigated lowland and rainfed rice, which is grown across 145 million hectares in more than 100 countries, are capable of generating large numbers of mosquito vectors of malaria, which causes more than 400,000 deaths per year worldwide. Many methods can control these vectors, but a systematic review has not previously been conducted. This study assesses whether larviciding, fish or intermittent irrigation can significantly reduce malaria vectors in rice fields whilst increasing rice yield. After a literature search for studies reporting the effect of larval control and rice cultivation practices on malaria vector densities in rice fields, 33 studies were eligible for meta-analysis. Larviciding was effective at reducing rice-field malaria vectors. Pooled analysis of five controlled time-series (CTS) studies with chemical insecticides showed an overall combined reduction of larval densities of 77% compared to no larviciding. Eight CTSs with biological larvicides showed a pooled reduction of 60% compared to no larviciding. Cultivating rice and fish together provided good control too: a pooled analysis of three CTSs showed an overall 82% reduction in anopheline larvae compared to no fish. Pooled analysis of four studies suggested that intermittent irrigation (using various timings and frequencies of drainage) is effective at reducing the abundance of late-stage anopheline larvae (pooled reduction = - 35%), but not overall immature abundance, compared to continuous flooding. We conclude that many interventions such as larvicides, fish and intermittent irrigation can provide riceland malaria vector control, but the critical obstacle to wider use is farmer acceptability. Future research should be led by the agricultural sector, with inputs from entomologists, to investigate malaria control co-benefits within high-yielding rice cultivation practices.

The Impact of the COVID-19 Pandemic on Tuberculosis Case Notification and Treatment Outcomes in Eswatini

Objectives: We investigated the impact of COVID-19 on tuberculosis (TB) case notification and treatment outcomes in Eswatini.

Methods: A comparative retrospective cohort study was conducted using TB data from eight facilities. An interrupted time series analysis, using segmented Poisson regression was done to assess the impact of COVID-19 on TB case notification comparing period before (December 2018-February 2020, n = 1,560) and during the pandemic (March 2020–May 2021, n = 840). Case notification was defined as number of TB cases registered in the TB treatment register. Treatment outcomes was result assigned to patients at the end of treatment according to WHO rules.

Results: There was a significant decrease in TB case notification (IRR 0.71, 95% CI: 0.60–0.83) and a significant increase in death rate among registrants during the pandemic (21.3%) compared to pre-pandemic (10.8%, p < 0.01). Logistic regression indicated higher odds of unfavorable outcomes (death, lost-to-follow-up, and not evaluated) during the pandemic than pre-pandemic (aOR 2.91, 95% CI: 2.17–3.89).

Conclusion: COVID-19 negatively impacted TB services in Eswatini. Eswatini should invest in strategies to safe-guard the health system against similar pandemics.

Impact of the COVID-19 pandemic on perinatal care and outcomes in the United States: An interrupted time series analysis

BACKGROUND

Hospitals quickly adapted perinatal care to mitigate SARS-CoV-2 transmission at the onset of the COVID-19 pandemic. The objective of this study was to estimate the impact of pandemic-related hospital policy changes on perinatal care and outcomes in one region of the United States.

METHODS

This interrupted time series analysis used retrospective data from consecutive singleton births at 15 hospitals in the Pacific Northwest from 2017 to 2020. The primary outcomes were those hypothesized to be affected by pandemic-related hospital policies and included labor induction, epidural use, oxytocin augmentation, mode of delivery, and early discharge (<48 hours after cesarean and <24 hours after vaginal births). Secondary outcomes included preterm birth, severe maternal morbidity, low 5-minute Apgar score, neonatal intensive care unit (NICU) admission, and 30-day readmission. Segmented Poisson regression models estimated the outcome level shift changes after the pandemic onset, controlling for underlying trends, seasonality, and stratifying by parity.

RESULTS

No statistically significant changes were detected in intrapartum interventions or mode of delivery after onset of the pandemic. Early discharge increased for all births following cesarean and vaginal birth. Newborn readmission rates increased but only among nulliparas (aRR: 1.49, 95%CI: 1.17, 1.91). Among multiparas, decreases were observed in preterm birth (aRR: 0.90, 95%CI: 0.84, 0.96), low 5-minute Apgar score (aRR: 0.75, 95%CI: 0.68, 0.81), and term NICU admission rates (aRR: 0.85, 95%CI: 0.80, 0.91).

CONCLUSIONS

Increases in early discharge and newborn readmission rates among nulliparas suggest a need for more postpartum support during the pandemic. Decreases in preterm birth and term NICU admission among multiparas may have implications beyond the pandemic and deserve further study.

Effect of epidemic management and control plan on COVID-19 mortality in Iran: an interrupted time series analysis

BACKGROUND

Globally, several measures have been taken to decrease COVID-19 mortality. However, the effectiveness of preventive measures on the mortality related to COVID-19 has not been fully assessed. Thus, the present study aimed the present study aimed to assess the success of COVID-19 epidemic management and control plan on the mortality associated with COVID-19 in Iran from February 19, 2020, to February 5, 2021.

METHODS

In the current quasi experimental study an interrupted time series analysis of daily collected data on confirmed deaths of COVID-19 occurred in Iran and in the world, were performed using Newey ordinary least squares regression-based methods.

RESULTS

In Iran, the trend of new deaths increased significantly every day until 24 November 2020 according to pre-intervention slope of [(OR 1.14, 95% CI 0.96-1.32,); P < 0.001]. The occurrence of new deaths had a decreasing trend after November 24, 2020, with a coefficient of [(OR -5.12, 95% CI -6.04 - -4.20), P < 0.001)]. But in the global level daily new deaths was increasing before [(OR 18.66, 95% CI 14.41-2292; P < 0.001)] and after the 24 November 2020 [(OR 57.14, 95% CI 20.80-93.49); P: 0.002].

CONCLUSIONS

Iranian COVID-19 epidemic management and control plan effectively reduced the mortality associated to COVID-19. Therefore, it is essential to continue these measures to prevent the increase in the number of deaths.

Impact of Three Safety Interventions Targeting Off-Label Use of Immediate-Release Fentanyl on Prescription Trends: Interrupted Time Series Analysis

Background: The Spanish health authorities are concerned by the off-label use of immediate-release formulations of fentanyl (IRF) in noncancer pain and cancer pain in patients with no chronic pain therapy. Aim: To evaluate the impact of different interventions to improve appropriateness of IRF prescription on off-label prescription. Patients and methods: We used interrupted time series (ITS) to estimate immediate and trend changes of IRF prescription for noncancer pain (NCP) and breakthrough cancer pain (BCP) in patients with and without chronic cancer pain therapy associated with two medication reviews (I1 and I2) and the issue of a safety warning letter (I3) with data from a Spanish region with 5 million inhabitants, from 2015 to 2018. Results: The use of IRF for NCP in the region Valencia was reduced from about 1,800 prescriptions per week to around 1,400. The first medication review was followed by an immediate level change of -192.66 prescriptions per week (p < 0.001) and a downward trend change of -6.75 prescriptions/week (p < 0.001), resulting in a post-intervention trend of -1.99 (p < 0.001). I2 was associated with a trend change of -23.07 (p < 0.001) prescriptions/week. After I3, the trend changed markedly to 27.23 additional prescriptions/week, for a final post-intervention trend of 2.17 (p < 0.001). Controlled-ITS provided comparable results. For potentially inappropriate BCP use, the second medication review was followed by a downward, immediate level change of -10.10 prescriptions/week (p = 0.011) and a trend change of 2.31 additional prescriptions/week (p < 0.001) and the issue of the safety warning (I3) was followed by a downward trend change of -2.09 prescriptions/week (p = 0.007). Conclusion: Despite IRF prescription for NCP decreased, the interventions showed modest and temporary effect on off-label prescription. Our results call for a review of the design and implementation of safety interventions addressing inappropriate opioid use.

Impact of COVID-19 on Healthcare Resource Utilisation Among Patients with Inflammatory Bowel Disease in the USA

BACKGROUND AND AIMS

The impact of the COVID-19 pandemic on patients with inflammatory bowel disease [IBD] is largely unknown. We characterised the impact of COVID-19 on IBD care by conducting an analysis of US health care claims data.

METHODS

We obtained de-identified, open-source, health insurance claims data, from January 2019 to December 2020, from the Symphony Health Integrated Dataverse for US adults with IBD, and measured the rates per 1000 patients of five outcomes: colonoscopies; new biologic or small molecule treatment initiations or treatment switches; new biologic or small molecule treatment initiations or treatment switches in patients who had a colonoscopy within the previous 60 days; IBD-related surgeries; and telehealth consultations.

RESULTS

For 2019 and 2020, 1.32 million and 1.29 million patients with IBD, respectively, were included in the analysis. In March-April 2020, the rates of colonoscopies [17.39 vs 34.44], new biologic or small molecule treatment initiations or switches in patients who had a colonoscopy within the previous 60 days [0.76 vs 1.18], and IBD-related surgeries [2.33 vs 2.99] per 1000 patients were significantly decreased versus January-February 2020; significant year on year decreases versus 2019 were also observed. Telehealth utilisation increased in March 2020 and remained higher than in 2019 up to December 2020.

CONCLUSIONS

Reduction in colonoscopies and subsequent initiation/switching of treatments during the COVID-19 pandemic suggest lost opportunities for therapy optimisation which may have an impact on longer-term patient outcomes. Increased utilisation of telehealth services may have helped address gaps in routine clinical care.

The impact of COVID-19 restrictions on online sales of HIV self-test kits and implications for HIV prevention: analysis of transaction data from a leading e-commerce platform in China

BACKGROUND

The effect of the COVID-19 epidemic on HIV self-testing (HIVST) remains unclear. We aimed to quantify the impact of COVID-restrictions on HIVST kit purchasing behaviors in mainland China.

METHODS

De-identified transaction data were retrieved from a large online shopping platform. An interrupted time series model was constructed to examine the impact of COVID-restrictions on the weekly number of anonymous customers purchasing HIVST kits, online orders, and purchased kits.

RESULTS

A total of 2.32 million individuals submitted 4.46 million orders for 4.84 million HIVST kits between 7 January 2016 and 22 April 2020. Compared to expected levels assuming COVID-19 epidemic and related restrictions had not happened, the number of purchasers, orders, and kits decreased by an estimated 10,500 (51.7%), 18,000 (55.3%) and 18,500 (54.9%) in the first week (23 January 2020 to 29 January 2020) after COVID-restrictions were implemented, respectively. As restrictions eased, the number of purchasers, orders, and kits increased by an average of 7.4%, 4.8%, and 4.9% per week, respectively. In the first week after COVID-restrictions were lifted (9 April 2020 to 15 April 2020), the number of purchasers returned to expected levels, whereas the number of orders and kits were still lower than expected levels. The impact of COVID-restrictions on outcomes at the beginning of COVID-restrictions and the increasing trends of outcomes were larger among those living in regions with higher COVID-19 incidence (e.g., Wuhan city and Hubei province).

CONCLUSIONS

Online sales of HIVST kits were significantly impacted by COVID-restrictions, and HIVST kit purchasing patterns returned to expected levels after restrictions were lifted.

Impact of introducing procalcitonin testing on antibiotic usage in acute NHS hospitals during the first wave of COVID-19 in the UK: a controlled interrupted time series analysis of organization-level data

BACKGROUND

Blood biomarkers have the potential to help identify COVID-19 patients with bacterial coinfection in whom antibiotics are indicated. During the COVID-19 pandemic, procalcitonin testing was widely introduced at hospitals in the UK to guide antibiotic prescribing. We have determined the impact of this on hospital-level antibiotic consumption.

METHODS

We conducted a retrospective, controlled interrupted time series analysis of organization-level data describing antibiotic dispensing, hospital activity and procalcitonin testing for acute hospitals/hospital trusts in England and Wales during the first wave of COVID-19 (24 February to 5 July 2020).

RESULTS

In the main analysis of 105 hospitals in England, introduction of procalcitonin testing in emergency departments/acute medical admission units was associated with a statistically significant decrease in total antibiotic use of -1.08 (95% CI: -1.81 to -0.36) DDDs of antibiotic per admission per week per trust. This effect was then lost at a rate of 0.05 (95% CI: 0.02-0.08) DDDs per admission per week. Similar results were found specifically for first-line antibiotics for community-acquired pneumonia and for COVID-19 admissions rather than all admissions. Introduction of procalcitonin in the ICU setting was not associated with any significant change in antibiotic use.

CONCLUSIONS

At hospitals where procalcitonin testing was introduced in emergency departments/acute medical units this was associated with an initial, but unsustained, reduction in antibiotic use. Further research should establish the patient-level impact of procalcitonin testing in this population and understand its potential for clinical effectiveness.

Impact of a Homeless Encampment Closure on Crime Complaints in the Bronx, New York City, 2017: Implications for Municipal Policy

Purpose

As part of COVID-19 control policy, the Centers for Disease Control and Prevention has advised local jurisdictions to permit the formation of homeless encampments to prevent community disease spread. This new federal public health guidance is in conflict with existing police policies in many jurisdictions to raze or evict homeless encampments upon discovery. However, no empirical research on homeless encampment policy actions exists.

Methods

This study utilized interrupted time series to estimate the impact of the 2017 closure of "the Hole"-a longstanding encampment of homeless people who use drugs in the Bronx, New York City-on crime complaints. Daily crime complaints originating from public spaces within 1 mile of the encampment were captured during the 30-day periods before and after closure.

Results

Closure was associated with no short-term changesin complaints [IRR=1.01; 95% CI (0.81-1.27)], with daily complaints remaining at baseline levels during the post-closure period [IRR 0.99; 95% CI (0.98-1.00)].

Discussion

Findings preliminarily suggest that the presence of a homeless encampment may not have been associated with increased levels of crime in the neighborhood where it was located. Future research is necessary to understand the health and social impacts of homeless encampments and inform municipal policymakers.

Effect of an Intensified Antibiotic Stewardship Program at an Orthopedic Surgery Department

Background: Institutional programs such as antibiotic stewardship (ABS) programs offer possibilities to monitor and modify antibiotic usage with the aim of reducing antibiotic resistance. In orthopedic units that treat peri-prosthetic joint infections (PJIs), ABS programs are still rare, however, there is extensive use of high-risk antibiotic agents and an increased risk for the occurrence of Clostridium difficile infections (CDIs). Patients and Methods: An ABS program was implemented at the Department of Orthopedic Surgery at a university hospital. Quarterly antibiotic consumption was measured in defined daily doses (DDDs) per 100 patient-days (PDs) at 10 quarters before the intervention and seven quarters after the intervention. The effect of the new antibiotic policy on drug use rates was evaluated using an interrupted time-series analysis. Estimated changes over time in the incidence of CDIs (cases per 1,000 PDs) were analyzed. Results: A remarkable percentual reduction in second-generation cephalosporin use of 83% (p < 0.001; pre-intervention level, 81.486 DDDs/100 patient-days; post-intervention level, 13.751 DDDs/100 PDs) and clindamycin administration of 78% (p < 0.001; pre-intervention level, 18.982 DDDs/100 PDs; post-intervention level, 4.216 DDDs/100 PDs) was observed after implementation of ABS interventions. Total antibiotic use declined by 25% (p < 0.001; pre-intervention level, 129.078 DDDs/100 PDs; post-intervention level, 96.826 DDDs/100 PDs). Conclusions: This research assessed the positive impact of an intensified ABS program at an orthopedic department specializing in PJIs. Antibiotic stewardship program interventions encourage the reduction of total antibiotic usage and especially high-risk antibiotic agents, associated with the development of antimicrobial resistance.

Sterile Insect Technique: Successful Suppression of an Aedes aegypti Field Population in Cuba

Simple Summary

The sterile insect technique (SIT) is a species-specific and environment-friendly method of insect control that relies on the release of large numbers of sterile insects. Mating released sterile males with wild females leads to a decrease in the reproductive potential and to the local suppression of the target population. There is increased interest in applying this approach to manage disease-transmitting mosquito populations. The main focus of this pilot trial was to assess the efficacy of the SIT for the suppression of Aedes aegypti populations. Two areas in Havana city, Cuba, were selected as control and release trial sites. The presence, density and fertility of the target wild population were monitored through a network of ovitraps. Approximately 1,270,000 irradiated Ae. aegypti males were released in the 50 ha target area over a period of 20 weeks. The released mosquitoes showed excellent mating competitiveness and induced high levels of sterility in the wild Ae. aegypti population. The target natural population was suppressed as reflected in the ovitrap index and in the mean number of eggs/trap values which dropped to zero by the last 3 weeks of the trial. We conclude that the released sterile male Ae. aegypti competed successfully and induced significant sterility in the local target Ae. aegypti population, resulting in suppression of the vector.

Abstract

Dengue virus infections are a serious public health problem worldwide. Aedes aegypti is the primary vector of dengue in Cuba. As there is no vaccine or specific treatment, the control efforts are directed to the reduction of mosquito populations. The indiscriminate use of insecticides can lead to adverse effects on ecosystems, including human health. The sterile insect technique is a species-specific and environment-friendly method of insect population control based on the release of large numbers of sterile insects, ideally males only. The success of this technique for the sustainable management of agricultural pests has encouraged its evaluation for the population suppression of mosquito vector species. Here, we describe an open field trial to evaluate the effect of the release of irradiated male Ae. aegypti on a wild population. The pilot trial was carried out in a suburb of Havana and compared the mosquito population density before and after the intervention, in both untreated control and release areas. The wild population was monitored by an ovitrap network, recording frequency and density of eggs as well as their hatch rate. A significant amount of sterility was induced in the field population of the release area, as compared with the untreated control area. The ovitrap index and the mean number of eggs/trap declined dramatically after 12 and 5 weeks of releases, respectively. For the last 3 weeks, no eggs were collected in the treatment area, clearly indicating a significant suppression of the wild target population. We conclude that the sterile males released competed successfully and induced enough sterility to suppress the local Ae. aegypti population.

The impact of childhood pneumococcal conjugate vaccine immunisation on all-cause pneumonia admissions in Hong Kong: A 14-year population-based interrupted time series analysis

BACKGROUND

Nine years after the introduction of pneumococcal conjugate vaccine (PCV) in the United States, Hong Kong (HK) introduced the vaccine to its universal childhood immunisation programme in 2009. We aimed to assess the impact of childhood PCV immunisation on all-cause pneumonia (ACP) admissions among the overall population of HK.

METHODS

In this population-based interrupted time series analysis, we used territory-wide population-representative electronic health records in HK to evaluate the vaccine impact. We identified hospitalised patients with a diagnosis of pneumonia from any cause between 2004 and 2017. We applied segmented Poisson regression to assess the gradual change in the monthly incidence of ACP admissions between pre- and post-vaccination periods. Negative outcome control, subgroup and sensitivity analyses were used to test the robustness of the main analysis.

FINDINGS

Over the 14-year study period, a total of 587,607 ACP episodes were identified among 357,950 patients. The monthly age-standardised incidence of ACP fluctuated between 33.42 and 87.44 per 100,000-persons. There was a marginal decreasing trend in pneumonia admissions after PCV introduction among overall population (incidence rate ratio [IRR]: 0·9965, 95% confidence interval [CI]: 0·9932-0·9998), and older adults (≥65 years, IRR: 0·9928, 95% CI: 0·9904-0·9953) but not in younger age groups.

INTERPRETATION

There was a marginally declining trend of overall ACP admissions in HK up to eight years after childhood PCV introduction. The significance disappeared when fitting sensitivity analyses. The results indicate the complexities of using non-specific endpoints for measuring vaccine effect and the necessity of enhancing serotype surveillance systems for replacement monitoring.

FUNDING

Health and Medical Research Fund, Food and Health Bureau of the Government of Hong Kong (Reference number: 18171272).

The impact of the COVID-19 lockdown on HIV care in 65 South African primary care clinics: an interrupted time series analysis

BACKGROUND

The effect of the COVID-19 pandemic on HIV outcomes in low-income and middle-income countries is poorly described. We aimed to measure the impact of the 2020 national COVID-19 lockdown on HIV testing and treatment in KwaZulu-Natal, South Africa, where 1·7 million people are living with HIV.

METHODS

In this interrupted time series analysis, we analysed anonymised programmatic data from 65 primary care clinics in KwaZulu-Natal province, South Africa. We included data from people testing for HIV, initiating antiretroviral therapy (ART), and collecting ART at participating clinics during the study period, with no age restrictions. We used descriptive statistics to summarise demographic and clinical data, and present crude summaries of the main outcomes of numbers of HIV tests per month, ART initiations per week, and ART collection visits per week, before and after the national lockdown that began on March 27, 2020. We used Poisson segmented regression models to estimate the immediate impact of the lockdown on these outcomes, as well as post-lockdown trends.

FINDINGS

Between Jan 1, 2018, and July 31, 2020, we recorded 1 315 439 HIV tests. Between Jan 1, 2018, and June 15, 2020, we recorded 71 142 ART initiations and 2 319 992 ART collection visits. We recorded a median of 41 926 HIV tests per month before lockdown (January, 2018, to March, 2020; IQR 37 838-51 069) and a median of 38 911 HIV tests per month after lockdown (April, 2020, to July, 2020; IQR 32 699-42 756). In the Poisson regression model, taking into account long-term trends, lockdown was associated with an estimated 47·6% decrease in HIV testing in April, 2020 (incidence rate ratio [IRR] 0·524, 95% CI 0·446-0·615). ART initiations decreased from a median of 571 per week before lockdown (IQR 498-678), to 375 per week after lockdown (331-399), with an estimated 46·2% decrease in the Poisson regression model in the first week of lockdown (March 30, 2020, to April 5, 2020; IRR 0·538, 0·459-0·630). There was no marked change in the number of ART collection visits (median 18 519 visits per week before lockdown [IQR 17 074-19 922] vs 17 863 visits per week after lockdown [17 509-18 995]; estimated effect in the first week of lockdown IRR 0·932, 95% CI 0·794-1·093). As restrictions eased, HIV testing and ART initiations gradually improved towards pre-lockdown levels (slope change 1·183/month, 95% CI 1·113-1·256 for HIV testing; 1·156/month, 1·085-1·230 for ART initiations).

INTERPRETATION

ART provision was generally maintained during the 2020 COVID-19 lockdown, but HIV testing and ART initiations were heavily impacted. Strategies to increase testing and treatment initiation should be implemented.

FUNDING

Wellcome Trust, Africa Oxford Initiative.

Estimating the power to detect a change caused by a vaccine from time series data

When evaluating the effects of vaccination programs, it is common to estimate changes in rates of disease before and after vaccine introduction. There are a number of related approaches that attempt to adjust for trends unrelated to the vaccine and to detect changes that coincide with introduction. However, characteristics of the data can influence the ability to estimate such a change. These include, but are not limited to, the number of years of available data prior to vaccine introduction, the expected strength of the effect of the intervention, the strength of underlying secular trends, and the amount of unexplained variability in the data. Sources of unexplained variability include model misspecification, epidemics due to unidentified pathogens, and changes in ascertainment or coding practice among others. In this study, we present a simple simulation framework for estimating the power to detect a decline and the precision of these estimates. We use real-world data from a pre-vaccine period to generate simulated time series where the vaccine effect is specified a priori. We present an interactive web-based tool to implement this approach. We also demonstrate the use of this approach using observed data on pneumonia hospitalization from the states in Brazil from a period prior to introduction of pneumococcal vaccines to generate the simulated time series. We relate the power of the hypothesis tests to the number of cases per year and the amount of unexplained variability in the data and demonstrate how fewer years of data influence the results.

Health Effects of Air-Quality Regulations in Seoul Metropolitan Area: Applying Synthetic Control Method to Controlled-Interrupted Time-Series Analysis

Despite enormous investment in air-quality regulations, there are only a few studies about the health effects of the air-quality regulations. By applying synthetic control methods to controlled-interrupted time-series analysis, this study aimed to test whether air-quality regulations implemented in Seoul metropolitan area since 2005 had reduced cardiovascular mortality rate in Seoul and Incheon. Each synthetic control for Seoul and Incheon was constructed to predict the counterfactual cardiovascular mortality rate through synthetic control methods. By using a synthetic control as a control group in controlled-interrupted time-series analysis, we tested whether the air-quality regulations had changed the trend of cardiovascular mortality rate in Seoul and Incheon after the intervention. The results showed a significant slope change in cardiovascular mortality rate in Seoul (coefficient: −0.001, 95% confidence interval (CI): −0.0015, −0.0004) and Incheon (coefficient: −0.0006, 95% CI: −0.0012, 0). This study suggests additional evidence that air-quality regulations implemented in the Seoul metropolitan areas since 2005 had beneficial effects on cardiovascular mortality rate in Seoul and Incheon.