Social contact mixing patterns are critical to model the transmission of communicable diseases, and have been employed to model disease outbreaks including COVID-19. Nonetheless, there is a paucity of studies on contact mixing in low and middle-income countries such as India. Furthermore, mathematical models of disease outbreaks do not account for the temporal nature of social contacts. We conducted a longitudinal study of social contacts in rural north India across three seasons and analysed the temporal differences in contact patterns. A contact diary survey was performed across three seasons from October 2015-16, in which participants were queried on the number, duration, and characteristics of contacts that occurred on the previous day. A total of 8,421 responses from 3,052 respondents (49% females) recorded characteristics of 180,073 contacts. Respondents reported a significantly higher number and duration of contacts in the winter, followed by the summer and the monsoon season (Nemenyi post-hoc, p<0.001). Participants aged 0-9 years and 10-19 years of age reported the highest median number of contacts (16 (IQR 12-21), 17 (IQR 13-24) respectively) and were found to have the highest node centrality in the social network of the region (pageranks = 0.20, 0.17). A large proportion (>80%) of contacts that were reported in schools or on public transport involved physical contact. To the best of our knowledge, our study is the first from India to show that contact mixing patterns vary by the time of the year and provides useful implications for pandemic control. We compared the differences in the number, duration and location of contacts by age-group and gender, and studied the impact of the season, age-group, employment and day of the week on the number and duration of contacts using multivariate negative binomial regression. We created a social network to further understand the age and gender-specific contact patterns, and used the contact matrices in each season to parameterise a nine-compartment agent-based model for simulating a COVID-19 epidemic in each season. Our results can be used to parameterize more accurate mathematical models for prediction of epidemiological trends of infections in rural India.

BackgroundThis analysis used retrospective data from the DISCOVER CKD observational study (NCT04034992) to describe the burden of and treatment pathways for hyperkalemia (HK) in patients with CKD. MethodsData were extracted from the following databases: UK Clinical Practice Research Datalink (2008-2019) and Japan Medical Data Vision (2008-2017). Patients with CKD (two eGFR measures <75 ml/min per 1.73 m2 recorded >= 90 days apart) and HK (at least two serum potassium [sK+] measures >5.0 mmol/L) were compared with patients without HK (sK+ <5.0 mmol/L); HK index event was the second sK+ measurement. Outcomes included baseline characteristics and treatment pathways for key medications (renin-angiotensin-aldosterone system inhibitors [RAASi], diuretics and potassium [K+] binders). ResultsIn the UK Clinical Practice Research Datalink, 37,713 patients with HK and 142,703 patients without HK were included for analysis (HK prevalence 20.9%). In the Japan Medical Data Vision, 5924 patients with HK and 74,272 patients without HK were included for analysis (HK prevalence 7.4%). In both databases, median eGFR was lower and comorbidities such as hypertension, heart failure, type 2 diabetes, and AKI were more prevalent among patients with versus without HK, and most patients were taking RAASi at the time of HK index. Treatment pathways were more heterogeneous in Japan; <0.2% of patients with CKD and HK in the United Kingdom initiated K+ binders within 3 months of HK index versus 18.7% in Japan. The proportions of patients with CKD and HK who stopped treatment with diuretics, K+ binders, and RAASi during follow-up were 48.7%, 76.5%, and 50.6%, respectively, in the United Kingdom, and 22.9%, 53.6%, and 29.2%, respectively, in Japan. ConclusionsHK was associated with increased comorbidity burden in patients with CKD. Variations in treatment pathways between the United Kingdom and Japan reflect the previous lack of a standardized approach to HK management in CKD.

Aims: To describe treatment pathways for key glucose-lowering therapies in individuals with chronic kidney disease (CKD) and type 2 diabetes (T2D) using retrospective data from DISCOVER CKD (NCT04034992). Methods: Data were extracted from the UK Clinical Practice Research Datalink (CPRD) linked to Hospital Episode Statistics data (2008-2020) and the US integrated Limited Claims and Electronic Health Records Database (LCED; 2012-2019). Eligible individuals were aged >= 18 years with CKD, identified by two consecutive estimated glomerular filtration rate (eGFR) measures (15-< 75 mL/ min/1.73 m(2); 90-730 days apart; index date was the second measurement) and T2D. Chronological treatment pathways for glucose-lowering therapies prescribed on or after CKD index to end of follow-up were computed. Median time and proportion of overall follow-up time on treatment were described for each therapy by database and by eGFR and urinary albumin-to-creatinine ratio (UACR) categories. Results: Of 36,951 and 4339 eligible individuals in the CPRD and LCED, respectively, median baseline eGFR was 67.8 and 64.9 mL/min/1.73 m(2); 64.2 and 63.9% received metformin prior to index; and median (interquartile range) time on metformin during follow-up was 917 (390-1671) and 454 (192-850) days (accounting for similar to 75% of follow-up time in both databases). The frequency of combination treatment increased over time. There were trends towards decreased metformin prescriptions with decreasing eGFR and increasing UACR within each eGFR category. Conclusions: Individuals with CKD and T2D had many combinations of therapies and substantial follow-up time on therapy. These results highlight opportunities for improved CKD management.

Historically, typhoid control has been achieved with water and sanitation interventions. Today, in an era of rising antimicrobial resistance (AMR), two World Health Organization-prequalified vaccines are available to accelerate control in the shorter term. Meanwhile, water and sanitation interventions could be implemented in the longer term to sustainably prevent typhoid in low- and middle-income countries. This article first approaches typhoid control from a historical perspective, subsequently presents how vaccination could complement water and sanitation activities, and finally discusses the challenges and opportunities for impactful control of typhoid infection. It also addresses data blind spots and knowledge gaps to focus on for typhoid control and to ultimately progress towards elimination. This article presents a synthesis of discussions held in December 2021 during a roundtable session at the "12th International Conference on Typhoid and Other Invasive Salmonelloses".

PURPOSE: We surveyed oncologists who treat classic Hodgkin lymphoma (cHL) as part of the CONNECT study to understand the treatment decision‐making process, including the impact of positron emission tomography/computed tomography (PET/CT) imaging. METHODS: US physicians self-identifying as oncologists, hematologists, or hematologists/oncologists with ≥2 years of practice experience who treated ≥1 adult with stage III/IV cHL in the frontline setting in the last year were surveyed (October 19-November 16, 2020). Physician demographics, guideline adherence, and PET/CT utilization, interpretation, and access barriers were assessed. RESULTS: In total, 301 physicians participated in the survey. Eighty-eight percent of physicians gave somewhat-to-significant consideration to NCCN guidelines. Most physicians (94%; n = 284) reported obtaining a PET/CT scan at diagnosis; of these physicians, 97% reported obtaining an interim PET/CT scan for stage III/IV cHL, with 65% typically obtaining an interim PET/CT scan after cycle 2. The Deauville 5-point scale (5PS) was the primary scoring system used to review PET/CT results by 62% of physicians, with a positive score defined as ≥3 by 44%, ≥4 by 37%, and ≥2 by 12% of physicians. Fifty-five percent of physicians reported difficulty in obtaining PET/CT scans. CONCLUSION: Although most physicians considered NCCN guidelines when treating patients with stage III/IV cHL, interim PET/CT scans after cycle 2 were not universally obtained. When PET/CT scans were obtained, Deauville 5PS scores were not always provided, and variability existed on what defined a positive score. These findings suggest that opportunities exist for education and improved PET-adapted treatment approaches.

Typhoid fever is a significant global health problem that impacts people living in areas without access to clean water and sanitation. However, collaborative international partnerships and new research have improved both knowledge of the burden in countries with endemic disease and the tools for improved surveillance, including environmental surveillance. Two typhoid conjugate vaccines (TCVs) have achieved World Health Organization prequalification, with several more in the development pipeline. Despite hurdles posed by the coronavirus disease 2019 pandemic, multiple TCV efficacy trials have been conducted in high-burden countries, and data indicate that TCVs provide a high degree of protection from typhoid fever, are safe to use in young children, provide lasting protection, and have the potential to combat typhoid antimicrobial resistance. Now is the time to double down on typhoid control and elimination by sustaining progress made through water, sanitation, and hygiene improvements and accelerating TCV introduction in high-burden locations.

ObjectivesDuring COVID-19 vaccination programmes, new safety signals have emerged for vaccines, including extremely rare cases of thrombosis with thrombocytopaenia syndrome (TTS). Background event rates before and during the pandemic are essential for contextualisation of such infrequent events. In the literature, most studies do not report an overall TTS event rate. Rather, background rates are mainly reported for subtypes of thrombotic/thromboembolic diagnoses included in the TTS clinical definition mostly by anatomical location, with reported rates for TTS subtypes varying widely. The objective of this study was to report prepandemic TTS background event rates in the general population.MethodsPrepandemic background TTS rates were generated via secondary data analysis using a cohort design in the IBM Truven MarketScan (now Merative MarketScan) US health insurance claims database, from 1 January 2019 to 31 December 2019. Two algorithms were applied: thrombocytopaenia occurring±7 days (algorithm 1) or occurring 1 day prior to ≤14 days after the thrombotic/thromboembolic event (algorithm 2).ResultsThe study population derived from the MarketScan database analysis included approximately 9.8 million adults (aged ≥18 years; mean age 45 years, 52% females). Using this study population, prepandemic background TTS incidence was estimated as 9.8–11.1 per 100 000 person-years. Event rates were higher in males and increased with age. Similar patterns were observed with both algorithms.ConclusionsThis study presents an estimate of aggregate prepandemic background TTS event rates including by type of thrombosis/thromboembolism and age group. The background event rates are dependent on the precision of capturing underlying TTS events in variable data sources, and the ability of electronic health records or insurance claims databases to reflect the TTS clinical definition. Differences between reported event rates demonstrate that estimating background event rates for rare, unprecedented safety events is methodologically challenging.

ObjectivesTo describe a flexible common data model (CDM) approach that can be efficiently tailored to study-specific needs to facilitate pooled patient-level analysis and aggregated/meta-analysis of routinely collected retrospective patient data from disparate data sources; and to detail the application of this CDM approach to the DISCOVER CKD retrospective cohort, a longitudinal database of routinely collected (secondary) patient data of individuals with chronic kidney disease (CKD).MethodsThe flexible CDM approach incorporated three independent, exchangeable components that preceded data mapping and data model implementation: (1) standardized code lists (unifying medical events from different coding systems); (2) laboratory unit harmonization tables; and (3) base cohort definitions. Events between different coding vocabularies were not mapped code-to-code; for each data source, code lists of labels were curated at the entity/event level. A study team of epidemiologists, clinicians, informaticists, and data scientists were included within the validation of each component.ResultsApplying the CDM to the DISCOVER CKD retrospective cohort, secondary data from 1,857,593 patients with CKD were harmonized from five data sources, across three countries, into a discrete database for rapid real-world evidence generation.ConclusionsThis flexible CDM approach facilitates evidence generation from real-world data within the DISCOVER CKD retrospective cohort, providing novel insights into the epidemiology of CKD that may expedite improvements in diagnosis, prognosis, early intervention, and disease management. The adaptable architecture of this CDM approach ensures scalable, fast, and efficient application within other therapy areas to facilitate the combined analysis of different types of secondary data from multiple, heterogeneous sources.

e24004 Background: The health and work productivity burden informal cHL patient (pt) caregivers face is unknown. As part of the US-based CONNECT study, we evaluated caregivers’ burden and role in treatment (tx) decisions by relation to the pt: spouse/partner (SP) vs other (parent, child, friend, other relative). Methods: The CONNECT caregiver survey was an IRB-approved online survey administered from Dec 2020-Mar 2021 to self-identified current or former adult cHL pt caregivers. Health-related quality of life (HRQoL, PROMIS-Global), work impact (WPAI), decision-making, tx selection, and physician communication were assessed. Statistical significance was at the 95% confidence level. Results: 209 caregivers (58% women; median age 47 yrs; 54% employed; 53% SP) completed the survey. At completion, 69% cared for pts diagnosed in the past 1-2 yrs; 48% of pts cared for had stage III/IV cHL and 58% were in remission/not receiving active tx. While caregiver HRQoL was similar to that of the general population on the PROMIS-Global, employed caregivers had work impairment (29%) from caregiving activities (Table) which was higher when the pt was on vs off tx. Caregiving began at pt symptom onset for more SP vs other caregivers (61 vs 27%), and after the pt’s first tx for more other vs SP caregivers (34 vs 5%). 88% of caregivers discussed tx options with the pt. Cure, caregivers’ top tx goal (49%), was rated higher by SP vs other caregivers (56 vs 42%). Tx decisions with the pt (54 vs 23%) and tx option discussions with the doctor (52 vs 28%) were more common for SP vs other caregivers. More SP vs other caregivers had extensive tx option discussions with the pt (88 vs 68%), said it was important the doctor discussed managing side effects (94 vs 84%), felt the doctor provided adequate information about side effects (91 vs 71%), and felt aligned with the pt’s tx goals (93 vs 79%). Caregivers noted COVID-19 impacts like limiting daily activities to reduce COVID-19 risks (72%). Conclusions: Although cHL pt caregivers reported good HRQoL, caregiving impacted their work productivity regardless of relation to the pt. Cure was caregivers’ top tx goal. SP vs other caregivers were more involved and earlier, reporting alignment with pt tx goals and decision-making.[Table: see text]

Introduction:Kidney Disease: Improving Global Outcomes (KDIGO) 2012 guidelines classify chronic kidney disease (CKD) risk or prognosis using estimated glomerular filtration rate (eGFR) and urinary albumin-to-creatinine ratio (UACR). We assessed patient characteristics and outcomes according to the KDIGO classification, using data from DISCOVER CKD (NCT04034992). Methods:Data were extracted from the US integrated Limited Claims and Electronic Health Record Dataset and TriNetX databases, and the UK Clinical Practice Research Datalink linked to Hospital Episode Statistics and Office for National Statistics databases. Eligible patients were aged ≥18 years with CKD, and identified by 2 consecutive eGFR measures (5 to <75 ml/min/1.73 m2; ≥90 days apart [maximum 730]) from January 2008. Index date was the second eGFR measurement; patients were categorized using the UACR measure closest to the index. Outcomes included patient characteristics, eGFR or UACR measurement frequency, and clinical outcomes per baseline KDIGO classification. Results:Across databases, only 8.6% of patients with 2 eGFR measures had ≥1 UACR measures. Among 123,807 eligible patients, prevalence of heart failure, hypertension, and type 2 diabetes increased with increasing albuminuria. Incidence rates of mortality and adverse cardiovascular and renal outcomes increased with declining baseline eGFR, and particularly with increasing albuminuria. Median number of eGFR and UACR tests per year post-index ranged from 1.6 to 2.5 and 0.5 to 0.6, respectively, across databases; there was no clear increase in UACR testing frequency following the KDIGO 2012 guidelines. Conclusion:Albuminuria monitoring is critical for optimal risk stratification in CKD, and our findings highlight an imperative for more regular UACR testing in clinical practice.

Background Long-term clinical outcome data from patients with non-dialysis-dependent (NDD) chronic kidney disease (CKD) are lacking. We characterized patients with NDD-CKD and anemia using real-world data from the USA. Methods This retrospective longitudinal observational study evaluated integrated Limited Claims and Electronic Health Record Data (IBM Health, Armonk, NY), including patients >= 18 years with two or more estimated glomerular filtration rate (eGFR) measures Results Comprising 22 720 patients (57.4% female, 63.9% CKD stage 3, median hemoglobin 12.5 g/dL), median (interquartile range) follow-up for patients with and without anemia were 2.9 (1.5-4.4) and 3.8 (2.2-4.8) years, respectively. The most prevalent comorbidities were dyslipidemia (57.6%), type 2 diabetes mellitus (38.8%) and uncontrolled hypertension (20.0%). Overall, 23.3% of patients had anemia, of whom 1.9% and <0.1% received erythropoiesis-stimulating agents (ESAs) or intravenous iron, respectively. Anemia prevalence increased with CKD stage from 18.2% (stage 3a) to 72.8% (stage 5). Patients with anemia had a higher incidence rate of hospitalizations for heart failure (1.6 versus 0.8 per 100 patient-years), CKD stage advancement (43.5 versus 27.5 per 100 patient-years), and a 40% eGFR decrease (18.1 versus 7.3 per 100 patient-years) versus those without anemia. Conclusions Anemia, frequently observed in NDD-CKD and associated with adverse clinical outcomes, is rarely treated with ESAs and intravenous iron. These data suggest that opportunities exist for improved anemia management in patients with NDD-CKD.

Background

Background. Real-world data for patients with chronic kidney disease (CKD), specifically pertaining to clinical management, metabolic control, treatment patterns, quality of life (QoL) and dietary patterns, are limited. Understanding these gaps using real-world, routine care data will improve our understanding of the challenges and consequences faced by patients with CKD, and will facilitate the long-term goal of improving their management and prognosis. Methods. DISCOVER CKD follows an enriched hybrid study design, with both retrospective and prospective patient cohorts, integrating primary and secondary data from patients with CKD from China, Italy, Japan, Sweden, the UK and the USA. Data will be prospectively captured over a 3-year period from >1000 patients with CKD who will be followed up for at least 1 year via electronic case report form entry during routine clinical visits and also via a mobile/tablet-based application, enabling the capture of patient-reported outcomes (PROs). In-depth interviews will be conducted in a subset of -100 patients. Separately, secondary data will be retrospectively captured from >2000 000 patients with CKD, extracted from existing datasets and registries. Results. The DISCOVER CKD program captures and will report on patient demographics, biomarker and laboratory measurements, medical histories, clinical outcomes, healthcare resource utilization, medications, dietary patterns, physical activity and PROs (including QoL and qualitative interviews). Conclusions. The DISCOVER CKD program will provide contemporary real-world insight to inform clinical practice and improve our understanding of the epidemiology and clinical and economic burden of CKD, as well as determinants of clinical outcomes and PROs from a range of geographical regions in a real-world CKD setting.

Background: Effective actions to slow chronic kidney disease (CKD) progression depend on early disease recognition. This study aimed to assess the prevalence of and factors associated with undiagnosed stage 3 CKD.Methods: REVEAL-CKD is a multinational initiative to assess undiagnosed CKD. From the US, we utilised TriNetX, a federated research network providing statistics on electronic health records. Adult patients, with two eGFR measurements ≥30 and <60 mL/min/1.732 at least 90 days apart, were identified between 2015-2020. The date of the second eGFR measurement was defined as the index date. Those with no CKD diagnosis code at any time before or up to 6 months after the index date were considered to have undiagnosed CKD.Results: The study cohort included 178,331 patients whose mean age at index date was 70.8 years (standard deviation (SD): 10.6). The proportion of patients with undiagnosed CKD was 62.4% (95% confidence interval [CI] 62.2 to 62.6). Patients with comorbidities or younger age had a lower undiagnosed rate (Table 1). Of 123,994 patients with undiagnosed CKD at the index date, 25% received a diagnosis at some point during follow-up, with a median time to diagnosis of 253 days.Conclusion: This study documented that a majority of stage 3 CKD patients were undiagnosed. These results suggest that an opportunity exists for more proactive CKD diagnosis and monitoring at early stages.View largeDownload slideView largeDownload slide DisclosureA. Abdul sultan: Employee; Self; AstraZeneca. S. Barone: Employee; Self; AstraZeneca. S. Kumar: Employee; Self; AstraZeneca, Stock/Shareholder; Self; AstraZeneca. H. Chen: None. K. Järbrink: Employee; Self; AstraZeneca. E. T. Wittbrodt: Employee; Self; AstraZeneca, Stock/Shareholder; Self; AstraZeneca. P. R. Kushner: Advisory Panel; Self; Abbott Diabetes, AstraZeneca, Boehringer Ingelheim Pharmaceuticals, Inc., Novo Nordisk, Speaker's Bureau; Self; AstraZeneca, Janssen Pharmaceuticals, Inc., Lilly Diabetes, Novo Nordisk.

Abstract Introduction Hodgkin lymphoma (HL) represents ~10% of all lymphomas in the United States (US) with classical HL (cHL) accounting for ~95% of all HL cases. cHL has a bimodal age distribution with peaks at ages 15-39 and ≥75 years. As part of CONNECT, the first real-world survey in cHL to include physicians, patients, and caregivers, patient treatment preferences for those with stage III or IV cHL were explored and differences evaluated between those aged <40 years (corresponding to the upper end of the age range for adolescence and young adulthood [US National Cancer Institute]) and ≥40 years at diagnosis. Methods The CONNECT patient survey was a non-interventional patient-centered survey. Participants included were aged ≥18 years at the time of participation (aged ≥12 years at diagnosis), diagnosed with cHL within the past 10 years, and previously or currently being treated for cHL in the US. The CONNECT survey was reviewed and approved by the New England Institutional Review Board and administered from December 30, 2020, to March 1, 2021. Results In CONNECT, 182 participants had stage III or IV cHL (64% female; 77% Caucasian) with 64% aged <40 years at diagnosis. Overall, median (interquartile range) age at cHL diagnosis was 32 (25-50) years (aged <40, 27 [23-32] years; ≥40, 57 [49-64] years). Sixty-two percent of participants were diagnosed with stage III or IV cHL within the past 2 years and 27% were receiving treatment at time of survey. Cure was ranked as the first or second goal of initial cHL treatment for 86% of participants aged <40 years and 52% of participants aged ≥40 years (P < 0.001; Figure A). A higher percentage of participants aged ≥40 than <40 years ranked living longer (43% vs 28%) and having better quality of life (26% vs 8%, P = 0.001) as the first or second goal for initial cHL treatment. Among those with stage III or IV cHL in remission (<40, n=105; ≥40, n=11), 86% aged <40 and 100% age ≥40 years ranked staying in remission as the first or second most important survivorship goal. At diagnosis, a significantly higher percentage of participants aged <40 than ≥40 years preferred to treat their cancer aggressively (79% vs 60%, P = 0.016; Figure B). These participants were willing to trade off short-term risks for long-term efficacy (93% vs 71%, P < 0.001; Figure B). However, 44% of those aged <40 and 45% of those aged ≥40 years were willing to make that same trade-off for long-term risk reduction. A significantly higher percentage of participants aged <40 than ≥40 years reported being informed by their health care provider (HCP) about the following short-term side effects: nausea/vomiting (93% vs 80%, P = 0.015), hair loss (97% vs 74%, P < 0.001), fatigue (96% vs 74%, P < 0.001), risk of infection from low blood counts (90% vs 62%, P < 0.001), low blood count (87% vs 63%, P < 0.001), numbness and tingling (91% vs 45%, P < 0.001), and muscle weakness (74% vs 55%, P = 0.014). Regardless of age, fewer participants reported being told about the long-term risks of cHL treatment with those aged <40 years being more informed about the risk of developing other cancers (73% vs 55%; P = 0.028) and infertility (74% vs 22%; P < 0.001), and those aged ≥40 years being more informed about stroke (40% vs 13%; P < 0.001). Most participants reported being told about the short-term (<40 years, 85%; ≥40 years, 72%) and long-term (< 40 years, 75%; ≥40 years, 62%) side effects of cHL treatment during a discussion of treatment options with their HCP. When asked about long-term side effects of greatest concern, a significantly higher percentage of participants aged <40 compared with ≥40 years were concerned about secondary cancers (81% vs 46%; P < 0.001) and infertility (23% vs 6%; P = 0.007) whereas a significantly higher percentage of those aged ≥40 compared with those <40 years were concerned about heart disease and stroke (58% vs 42%; P = 0.046) and infections (31% vs 4%; P < 0.001). Conclusion Treatment goals differ significantly between participants with stage III or IV cHL based primarily on age, with those aged <40 years focusing on cure and aggressive treatments and those ≥40 years focusing on living longer and obtaining a good quality of life. Additionally, participants aged <40 compared with those ≥40 years were more willing to accept short-term risks in exchange for long-term benefits. Lastly, regardless of age, most participants were told about short-term and long-term side effects in discussion of treatment options with their HCP. Figure 1 Figure 1. Disclosures Flora: Seagen, Inc: Research Funding. Parsons: SeaGen: Consultancy. Liu: Seagen, Inc: Current Employment, Current equity holder in publicly-traded company. Yu: Seagen, Inc: Current Employment, Current equity holder in publicly-traded company. Fanale: Seagen, Inc: Current Employment, Current equity holder in publicly-traded company. Kumar: Seagen, Inc: Consultancy. Byrd: Seagen, Inc: Research Funding.

Background: Transmission of respiratory pathogens such as SARS-CoV-2 depends on patterns of contact and mixing across populations. Understanding this is crucial to predict pathogen spread and the effectiveness of control efforts. Most analyses of contact patterns to date have focused on high-income settings. Methods: Here, we conduct a systematic review and individual-participant meta-analysis of surveys carried out in low- and middle-income countries and compare patterns of contact in these settings to surveys previously carried out in high-income countries. Using individual-level data from 28,503 participants and 413,069 contacts across 27 surveys, we explored how contact characteristics (number, location, duration, and whether physical) vary across income settings. Results: Contact rates declined with age in high- and upper-middle-income settings, but not in low-income settings, where adults aged 65+ made similar numbers of contacts as younger individuals and mixed with all age groups. Across all settings, increasing household size was a key determinant of contact frequency and characteristics, with low-income settings characterised by the largest, most intergenerational households. A higher proportion of contacts were made at home in low-income settings, and work/school contacts were more frequent in high-income strata. We also observed contrasting effects of gender across income strata on the frequency, duration, and type of contacts individuals made. Conclusions: These differences in contact patterns between settings have material consequences for both spread of respiratory pathogens and the effectiveness of different non-pharmaceutical interventions. Funding: This work is primarily being funded by joint Centre funding from the UK Medical Research Council and DFID (MR/R015600/1).