Evaluating newly approved drugs in combination regimens for multidrug-resistant tuberculosis with fluoroquinolone resistance (endTB-Q): study protocol for a multi-country randomized controlled trial

BACKGROUND

Treatment for fluoroquinolone-resistant multidrug-resistant/rifampicin-resistant tuberculosis (pre-XDR TB) often lasts longer than treatment for less resistant strains, yields worse efficacy results, and causes substantial toxicity. The newer anti-tuberculosis drugs, bedaquiline and delamanid, and repurposed drugs clofazimine and linezolid, show great promise for combination in shorter, less-toxic, and effective regimens. To date, there has been no randomized, internally and concurrently controlled trial of a shorter, all-oral regimen comprising these newer and repurposed drugs sufficiently powered to produce results for pre-XDR TB patients.

METHODS

endTB-Q is a phase III, multi-country, randomized, controlled, parallel, open-label clinical trial evaluating the efficacy and safety of a treatment strategy for patients with pre-XDR TB. Study participants are randomized 2:1 to experimental or control arms, respectively. The experimental arm contains bedaquiline, linezolid, clofazimine, and delamanid. The control comprises the contemporaneous WHO standard of care for pre-XDR TB. Experimental arm duration is determined by a composite of smear microscopy and chest radiographic imaging at baseline and re-evaluated at 6 months using sputum culture results: participants with less extensive disease receive 6 months and participants with more extensive disease receive 9 months of treatment. Randomization is stratified by country and by participant extent-of-TB-disease phenotype defined according to screening/baseline characteristics. Study participation lasts up to 104 weeks post randomization. The primary objective is to assess whether the efficacy of experimental regimens at 73 weeks is non-inferior to that of the control. A sample size of 324 participants across 2 arms affords at least 80% power to show the non-inferiority, with a one-sided alpha of 0.025 and a non-inferiority margin of 12%, against the control in both modified intention-to-treat and per-protocol populations.

DISCUSSION

This internally controlled study of shortened treatment for pre-XDR TB will provide urgently needed data and evidence for clinical and policy decision-making around the treatment of pre-XDR TB with a four-drug, all-oral, shortened regimen.

TRIAL REGISTRATION

ClinicalTrials.Gov NCT03896685. Registered on 1 April 2018; the record was last updated for study protocol version 4.3 on 17 March 2023.

Adaptation and validation of a TB stigma scale for adolescents in Lima, Peru

BACKGROUND: TB-related stigma contributes to poor clinical outcomes and reduced wellbeing for affected individuals. Adolescents may be particularly susceptible to TB-related stigma due to their heightened sensitivity to peer acceptance, yet few studies have evaluated TB-related stigma in this group. Without a validated scale, it remains challenging to measure TB-related stigma in adolescents.METHODS: We adapted and validated the Van Rie TB Stigma Scale (VTSS) for adolescents on treatment for rifampicin-susceptible TB in Lima, Peru. The modified stigma scale was administered within a larger survey, which measured other psychosocial factors, including depression, adverse childhood experiences (ACEs), and social support. Data analysis included factor analysis, internal consistency, and convergent validity.RESULTS: From October 2020 to September 2021, 249 adolescents (individuals aged 10-19 years) completed the survey. Preliminary confirmatory factor analysis led to removal of two items. The final 10-item scale demonstrated good internal consistency (Cronbach's α = 0.82) and adequate model fit (χ²/df = 2.0; root mean square error of approximation: 0.06; comparative fit index: 0.94; Tucker-Lewis Index: 0.92: standardized root mean square residual: 0.05). Stigma was positively correlated with ACEs (γ = 0.13), depression (γ = 0.39), and suicidal ideation (γ = 0.27), and negatively correlated with social support (γ = -0.19).CONCLUSION: This adolescent TB stigma scale may serve as a practical tool to measure TB-related stigma and evaluate the impact of stigma-reduction interventions in adolescents.

Person-centered strategies for delivering TB diagnostic services in Lima, Peru

SETTING

Lima, Peru.

OBJECTIVE

To close the gap in TB diagnosis, TB diagnostic services must match care-seeking preferences. We sought to identify preferred strategies for delivering TB diagnostic services and to determine whether preferences differ among demographic groups.

DESIGN

During May 2022-January 2023, we recruited adults who recently initiated treatment for pulmonary TB. We used an object-case best-worst scaling instrument to assess the desirability of nine hypothetical strategies for delivering TB diagnostic services. A t-test was used to assess differences in preference scores between groups.

RESULTS

Among 150 participants, the strategies with the highest preference scores were an integrated mobile unit offering screening for multiple conditions, expedited attention at the health center, and home-based screening. These were strongly preferred by 42%, 25%, and 27% of participants, respectively, and 80% of participants strongly preferred at least one of the three. Expedited attention at the health center scored more highly among people who experienced >2 months delay in TB diagnosis compared to those who experienced a more rapid diagnosis (0.37 ± 0.06 vs. 0.17 ± 0.06; P = 0.031).

CONCLUSION

Providing person-centered TB diagnostic services at diverse access points could help reach different populations, which could promote early diagnosis and help close the diagnosis gap.

Latent TB and depressive symptoms in household contacts of persons with active TB

BACKGROUND: Depression is common among persons with TB and is associated with poor clinical outcomes. However, little is known about the relationship between latent TB infection (LTBI) and depression. We assessed the association between LTBI and depressive symptoms among household contacts (HHCs) of patients receiving TB treatment.METHODS: We enrolled 1,009 HHCs of 307 patients receiving TB treatment in Lima, Peru, during 2016-2018. At enrollment, HHC LTBI status was assessed using the interferon-gamma release assay (IGRA). Depressive symptoms were assessed at baseline and 12 months later using the Patient Health Questionnaire-9 (PHQ-9) with a cut-off of ≥5. We used logistic regression to estimate the odds ratio (OR) for PHQ-9 ≥5, comparing HHCs with and without baseline LTBI.RESULTS: Among 921 HHCs, 374 (41.0%) had LTBI at baseline, and 69 (12.4%) of 567 HHCs had PHQ-9 ≥5. Compared to HHCs without LTBI at enrollment, those with LTBI had almost two times the odds of PHQ-9 ≥5 at follow-up after controlling for potential confounders (adjusted OR 1.93, 95% CI 1.09-3.39); this association was driven by greater severities of depressive symptoms.CONCLUSION: HHCs with LTBI had increased odds of depressive symptoms 1 year later. This population may benefit from mental health screening and interventions integrated into TB programs.

Culture-negative TB: clinical characteristics, risk factors and treatment outcomes

BACKGROUND: Although culture remains the standard for TB diagnosis, 15-20% of patients diagnosed and treated for TB are culture-negative. We explored clinical characteristics, risk factors and treatment outcomes for culture-negative TB in a Peruvian cohort.METHODS: We recruited 4,500 index TB patients and 10,160 household contacts in Lima, Peru, and enrolled 692 secondary patients diagnosed with TB during follow-up of household contacts. We analyzed smear and culture status, sociodemographic factors, clinical characteristics and TB treatment outcomes to compare culture-negative and positive patients.RESULTS: Of the 4,880 adult patients, 915 (18.8%) were culture-negative. Culture-negative patients were less likely to report symptoms of TB disease and disease of longer duration. A multivariate analysis showed no statistically significant difference in loss to follow-up, treatment failure or recurrence between the culture-negative and -positive groups but a higher rate of death among culture-negative patients with an adjusted OR of 1.65 (95% CI 1.05-2.60). In a multivariate analysis of determinants of culture negativity, older age, substance use and being a secondary case were associated with culture status.CONCLUSIONS: More recognition and awareness of culture-negative TB is key for early and correct diagnosis to reduce transmission and improve treatment outcomes.

Outcomes of WHO-conforming, longer, all-oral multidrug-resistant TB regimens and analysis implications

BACKGROUND: Evidence of the effectiveness of the WHO-recommended design of longer individualized regimens for multidrug- or rifampicin-resistant TB (MDR/RR-TB) is limited.OBJECTIVES: To report end-of-treatment outcomes for MDR/RR-TB patients from a 2015-2018 multi-country cohort that received a regimen consistent with current 2022 WHO updated recommendations and describe the complexities of comparing regimens.METHODS: We analyzed a subset of participants from the endTB Observational Study who initiated a longer MDR/RR-TB regimen that was consistent with subsequent 2022 WHO guidance on regimen design for longer treatments. We excluded individuals who received an injectable agent or who received fewer than four likely effective drugs.RESULTS: Of the 759 participants analyzed, 607 (80.0%, 95% CI 77.0-82.7) experienced successful end-of-treatment outcomes. The frequency of success was high across groups, whether stratified on number of Group A drugs or fluoroquinolone resistance, and ranged from 72.1% to 90.0%. Regimens were highly variable regarding composition and the duration of individual drugs.CONCLUSIONS: Longer, all-oral, individualized regimens that were consistent with 2022 WHO guidance on regimen design had high frequencies of treatment success. Heterogeneous regimen compositions and drug durations precluded meaningful comparisons. Future research should examine which combinations of drugs maximize safety/tolerability and effectiveness.

Using digital chatbots to close gaps in healthcare access during the COVID-19 pandemic

INTRODUCTION

Chatbots have emerged as a first link to care in recent years. The COVID-19 pandemic, and consequent health system disruptions, expanded their use. Socios En Salud (SES) introduced chatbots in Peru, which experienced one of the highest excess COVID mortalities in the world.

METHODS

SES and the government identified unmet population health needs, which could be amenable to virtual interventions. Chatbots were developed to screen individuals for these conditions; we describe the period of deployment, number of screenings, and number of people who received services.

RESULTS

Between April 2020 and May 2021, SES deployed nine ChatBots: four for mental health, two for maternal and child health, and three for chronic diseases: breast cancer, hypertension, diabetes mellitus, and obesity. Mental health services were provided to 42,932 people, 99.99% of those offered services. The other ChatBots reached fewer people. Overall, more than 50% of eligible people accepted chatbot-based services.

DISCUSSION

ChatBot use was highest for mental health. Chatbots may increase connections between a vulnerable population and health services; this is likely dependent on several factors, including condition, population, and penetration of smart phones. Future research will be critical to understand user experience and preferences and to ensure that chatbots link vulnerable populations to appropriate, high-quality care.

A structured community engagement strategy to support uptake of TB active case-finding

BACKGROUND: In Lima, Peru, a mobile TB screening program (“TB Móvil”) was implemented in high TB prevalence districts to increase TB screening. Community engagement activities to promote TB Móvil were simultaneously conducted.OBJECTIVE: To describe a structured, theory-driven community engagement strategy to support the uptake of TB Móvil.METHODS: We adapted Popular Opinion Leader (POL), an evidence-based social networking intervention previously used in Peru to promote HIV testing, for TB Móvil. Community health workers, women who run soup kitchens, and motorcycle taxi drivers served as “popular opinion leaders” who disseminated information about TB Móvil in everyday conversations, aided by a multi-media campaign. Performance indicators of POL included the number/characteristics of persons screened; number of multimedia elements; and proportion of persons with abnormal radiographs hearing about TB Móvil before attending.RESULTS: Between February 2019 and January 2020, 63,899 people attended the TB Móvil program at 210 sites; 60.1% were female. The multimedia campaign included 36 videos, 16 audio vignettes, flyers, posters, community murals and “jingles.” Among attendees receiving an abnormal chest X-ray suggestive of TB, 48% (6,935/14,563) reported hearing about TB Móvil before attending.CONCLUSIONS: POL promotes the uptake of TB Móvil and should be considered as a strategy for increasing TB screening uptake.

Integrated screening and testing for TB and COVID-19 in Peru

We describe the experience of integrating COVID-19 screening and testing into a mobile TB screening unit in Lima, Peru. All attendees received chest radiographs, which were analysed using CAD4TB and CAD4COVID; Xpert MTB/RIF Ultra was used to test for TB, and antibody and polymerase chain reaction (PCR) for SARS-CoV-2. One Xpert-positive TB case was diagnosed per 168 people screened, one person with SARS-CoV-2 antibodies per 3 people screened, and one PCR-confirmed SARS-CoV-2 infection per 8 people screened. Integrated screening can help to avoid delays in the diagnosis of both TB and COVID-19.

Evaluating newly approved drugs for multidrug-resistant tuberculosis (endTB): study protocol for an adaptive, multi-country randomized controlled trial

BACKGROUND

Treatment of multidrug- and rifampin-resistant tuberculosis (MDR/RR-TB) is expensive, labour-intensive, and associated with substantial adverse events and poor outcomes. While most MDR/RR-TB patients do not receive treatment, many who do are treated for 18 months or more. A shorter all-oral regimen is currently recommended for only a sub-set of MDR/RR-TB. Its use is only conditionally recommended because of very low-quality evidence underpinning the recommendation. Novel combinations of newer and repurposed drugs bring hope in the fight against MDR/RR-TB, but their use has not been optimized in all-oral, shorter regimens. This has greatly limited their impact on the burden of disease. There is, therefore, dire need for high-quality evidence on the performance of new, shortened, injectable-sparing regimens for MDR-TB which can be adapted to individual patients and different settings.

METHODS

endTB is a phase III, pragmatic, multi-country, adaptive, randomized, controlled, parallel, open-label clinical trial evaluating the efficacy and safety of shorter treatment regimens containing new drugs for patients with fluoroquinolone-susceptible, rifampin-resistant tuberculosis. Study participants are randomized to either the control arm, based on the current standard of care for MDR/RR-TB, or to one of five 39-week multi-drug regimens containing newly approved and repurposed drugs. Study participation in all arms lasts at least 73 and up to 104 weeks post-randomization. Randomization is response-adapted using interim Bayesian analysis of efficacy endpoints. The primary objective is to assess whether the efficacy of experimental regimens at 73 weeks is non-inferior to that of the control. A sample size of 750 patients across 6 arms affords at least 80% power to detect the non-inferiority of at least 1 (and up to 3) experimental regimens, with a one-sided alpha of 0.025 and a non-inferiority margin of 12%, against the control in both modified intention-to-treat and per protocol populations.

DISCUSSION

The lack of a safe and effective regimen that can be used in all patients is a major obstacle to delivering appropriate treatment to all patients with active MDR/RR-TB. Identifying multiple shorter, safe, and effective regimens has the potential to greatly reduce the burden of this deadly disease worldwide.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier NCT02754765. Registered on 28 April 2016; the record was last updated for study protocol version 3.3, on 27 August 2019.

Uncovering reasons for treatment initiation delays among children with TB in Lima, Peru

BACKGROUND: Timely diagnosis and treatment of pediatric tuberculosis (TB) is critical to reducing mortality but remains challenging in the absence of adequate diagnostic tools. Even once a TB diagnosis is made, delays in treatment initiation are common, but for reasons that are not well understood.METHODS: To examine reasons for delay post-diagnosis, we conducted semi-structured interviews with Ministry of Health (MoH) physicians and field workers affiliated with a pediatric TB diagnostic study, and caregivers of children aged 0-14 years who were diagnosed with pulmonary TB in Lima, Peru. Interviews were analyzed using systematic comparative and descriptive content analysis.RESULTS: We interviewed five physicians, five field workers and 26 caregivers with children who initiated TB treatment < 7 days after diagnosis (n = 15) or who experienced a delay of ≥7 days (n = 11). Median time in delay from diagnosis to treatment initiation was 26 days (range 7-117). Reasons for delay included: health systems challenges (administrative hurdles, medication stock, clinic hours), burden of care on families and caregiver perceptions of disease severity.CONCLUSION: Reasons for delay in treatment initiation are complex. Interventions to streamline administrative processes and tools to identify and support families at risk for delays in treatment initiation are urgently needed.

Introducing new and repurposed TB drugs: the endTB experience

In 2015, the initiative Expand New Drug Markets for TB (endTB) began, with the objective of reducing barriers to access to the new and repurposed TB drugs. Here we describe the major implementation challenges encountered in 17 endTB countries. We provide insights on how national TB programmes and other stakeholders can scale-up the programmatic use of new and repurposed TB drugs, while building scientific evidence about their safety and efficacy. For any new drug or diagnostic, multiple market barriers can slow the pace of scale-up. During 2015-2019, endTB was successful in increasing the number of patients receiving new and repurposed TB drugs in 17 countries. The endTB experience has many lessons, which are relevant to country level introduction of new TB drugs, as well as non-TB drugs and diagnostics. For example: the importation of TB drugs is possible even in the absence of registration; emphasis on good clinical monitoring is more important than pharmacovigilance reporting; national guidelines and expert committees can both facilitate and hinder innovative practice; clinicians use new and repurposed TB drugs when they are available; data collection to generate scientific evidence requires financial and human resources; pilot projects can drive national scale-up.

Performance of a household tuberculosis exposure survey among children in a Latin American setting

OBJECTIVE: To evaluate the performance of a survey that quantifies the intensity of household tuberculosis (TB) exposure among children.METHODS: Children aged 0-14 years in Lima, Peru, with ≥1 signs and/or symptoms of TB and a history of contact with an adult TB patient were included. The 10-question survey was administered to caregivers and addressed sleep proximity, frequency of exposure, and infectiousness of the contact. Infection status was determined using tuberculin skin tests (TSTs). The exposure scale was evaluated for association with TST positivity using mixed-effects regression analyses.RESULTS: The exposure score was significantly associated with TST positivity (age-adjusted odds ratio [aOR] 1.14, 95%CI 1.02-1.28). We observed a stronger association with TST positivity in children aged ≤5 years; (aOR 1.23, 95%CI 1.07-1.41) and no association in children 6-14 years of age (aOR 0.99, 95%CI 0.82-1.20).CONCLUSION: This survey was easy to use and modestly successful in predicting TST positivity in children aged ≤5 years. It may be a useful resource for clinicians for diagnosing TB in children, and for national TB programs aiming to scale up preventive therapy initiatives.

Feasibility and yield of screening for non-communicable diseases among treated tuberculosis patients in Peru

INTRODUCTION

The increasing prevalence of non-communicable diseases (NCDs) poses a major challenge to low- and middle-income countries. Patients' engagement with health services for anti-tuberculosis treatment provides an opportunity for screening for NCDs and for linkage to care.

METHODS

We explored the feasibility and yield of screening for NCDs in patients treated for tuberculosis (TB) in Lima, Peru, as part of a study focused on chronic respiratory sequelae. A representative sample of community controls was recruited from the same geographical area. Screening entailed taking a medical history and performing ambulatory blood pressure measurement and urinalysis.

RESULTS

A total of 177 participants with previous TB (33 with multidrug-resistant TB) and 161 community controls were evaluated. There was an almost four-fold increased prevalence of self-reported diabetes mellitus (DM) in the TB group (adjusted prevalence ratio 3.66, 95%CI 1.68-8.01). Among those without self-reported DM, 3.3% had glycosuria, with a number needed to screen (NNS) of 31. The NNS to find one (new) case of hypertension or proteinuria in the TB group was respectively 24 and 5.

CONCLUSION

Patient-centred care that includes pragmatic NCD screening is feasible in TB patients, and the treatment period provides a good opportunity to link patients to ongoing care.

Knowledge of tuberculosis and vaccine trial preparedness in Lima, Peru

SETTING

A safe, effective vaccine would improve tuberculosis (TB) control worldwide. Extensive community engagement will be essential to ensure the interest and participation of populations at highest risk.

OBJECTIVE/METHOD

To inform the potential implementation of efficacy studies, we assessed TB knowledge, attitudes towards licensed vaccines and willingness to participate in future TB vaccine efficacy trials among 262 household contacts of 79 recently diagnosed pulmonary TB cases in Lima, Peru.

RESULTS

Overall knowledge of TB was low. Only 41.6% of household contacts perceived themselves as being at high risk of acquiring TB. Slightly above half (54.2%) indicated willingness to participate in a TB vaccine trial. After clustered analysis adjusting for homogeneity among families, willingness to enroll was associated with belief that receiving all recommended vaccinations is important (adjusted OR [aOR] 3.28, P = 0.016), desire to know more about TB risk factors and clinical trials (aOR 2.60, P = 0.004), older age (aOR 1.02, P = 0.027) and TB knowledge (aOR 0.05, P = 0.039).

CONCLUSION

Barriers to participation in TB vaccine trials exist among individuals at high risk for TB. Targeted education about TB risk factors, TB transmission and education about the clinical trial process will be critical for laying the groundwork for future vaccine trials.

Barriers to the treatment of childhood tuberculous infection and tuberculosis disease: a qualitative study

SETTING

In 2012, Peru's National TB Program (NTP) reported approximately 2400 incident cases of tuberculosis (TB) disease in children aged <15 years. Peru's TB burden is concentrated in the Lima metropolitan area, particularly in poor districts such as El Agustino and La Victoria, where this study was conducted.

OBJECTIVE

To identify barriers to the treatment of childhood tuberculous infection and TB disease in Lima from the perspective of front-line providers and patients' families.

DESIGN

We conducted 10 semi-structured focus groups with 53 purposefully sampled primary care providers, community health workers, and parents/guardians of pediatric TB patients. We also completed nine in-depth interviews with National TB Program administrators and pulmonologists specializing in TB. Two authors performed inductive thematic analysis and identified emerging themes.

RESULTS

Four main treatment barriers emerged from the data: 1) dosing errors, 2) time- and labor-intensive preparation and administration of medications, 3) provider concern that isoniazid preventive therapy (IPT) generates isoniazid resistance, and 4) poor adherence to IPT.

CONCLUSION

Our findings highlight the urgent need for child-friendly formulations, provider and parent/guardian education about IPT, and strategies to promote adherence to IPT, including support and supervision by health workers and/or regimens with fewer doses.

Mental disorders and drug/alcohol use in patients commencing extensively drug-resistant tuberculosis treatment

Mental disorders and alcohol/drug use worsen treatment outcomes for multidrug-resistant tuberculosis (TB), but data are lacking for extensively drug-resistant (XDR) TB. We investigated the association of baseline mental disorders and alcohol/drug use on XDR-TB treatment outcomes in a retrospective study of 53 XDR-TB Peruvian patients during 2010-2012. Logistic regression estimated the odds ratios for unfavourable XDR-TB treatment outcomes. Overall treatment success was 25%. Mental disorders and drug/alcohol use were found in respectively 22.4% and 20.4% of patients; neither were associated with unfavourable treatment outcomes. Future research should explore the relationship between mental health and drug/alcohol use in XDR-TB treatment outcomes.

Barriers to the diagnosis of childhood tuberculosis: a qualitative study

SETTING

In 2012, Peru's National Tuberculosis Program (NTP) reported that children aged 0-14 years accounted for 7.9% of the country's tuberculosis (TB) incidence. This figure is likely an underestimate due to suboptimal diagnosis of childhood TB.

OBJECTIVE

To identify barriers to childhood TB diagnosis in Lima, Peru.

DESIGN

Using semi-structured guides, moderators conducted in-depth interviews with four NTP administrators and five pulmonologists specializing in TB and 10 focus groups with 53 primary care providers, community health workers (CHWs), and parents and/or guardians of pediatric TB patients. Two authors independently performed inductive thematic analysis and identified emerging themes.

RESULTS

Participants identified five barriers to childhood TB diagnosis: ignorance and stigma among the community, insufficient contact investigation, limited access to diagnostic tests, inadequately trained health center staff, and provider shortages.

CONCLUSION

Recent efforts to increase childhood TB detection have centered on the development of new technologies. However, our findings demonstrate that many diagnostic barriers are rooted in socio-economic and health system problems. Potential solutions include implementing multimedia campaigns and community education to reduce ignorance and stigma, prioritizing contact investigation for high-risk households, and training primary care providers and CHWs to recognize and evaluate childhood TB.

Clinical presentation of children with pulmonary tuberculosis: 25 years of experience in Lima, Peru

OBJECTIVE

To describe clinical presentation across age groups in 2855 children with pulmonary tuberculosis (TB) attending the Children's Hospital, Lima, Peru, to improve the diagnosis, treatment and care of childhood TB.

DESIGN

Children aged 0-14 years admitted between 1 January 1973 and 31 December 1997 with active pulmonary TB were enrolled. Demographic information, history, physical examination data, laboratory and microbiological results, chest radiograph data, disease classification, treatment and adverse effect data, and outcome at the time of discharge were recorded by pulmonologists using detailed chart abstractions.

RESULTS

Of the 2855 enrollees, 47% were malnourished and 56% had a household contact. Older children presented with classic TB symptoms, while weight loss and anorexia were rare in children aged <5 years. Microbiological or pathologic confirmation was obtained in 71% of children aged 10-14 years compared with 34% of children aged <2 years; however, severe extra-pulmonary TB was most common among children aged <2 years (41%).

CONCLUSION

Classic TB symptoms should be considered when making a diagnosis; however, systematic symptoms among young children are also important. In high-burden settings, clinicians should have a low threshold to diagnose and treat children for TB across all ages, even in the context of a negative tuberculin skin test result and lack of micro-pathological confirmation.