Worldwide, the population is ageing. As the population ages, so does the prevalence of age-related diseases such as arthritis, osteoporosis, diabetes, hypertension, cancer and dementia, increasing the demand on health and social care services. The evidence underpinning treatments and interventions for most health and social care issues is derived from populations younger than 80 years of age because this age group is often excluded from taking part in clinical trials. This raises concerns that many established treatments may not be the most suitable or effective approach for those aged 80 years or more. Our aim was to produce an interactive evidence and gap map to provide an overview of the volume, diversity and nature of the evidence on health and social care interventions that target adults over 80 years of age. We searched 18 databases: Medline, PsycINFO, HMIC, Social Policy and Practice, Ageline, CINAHL Complete, ASSIA, PQDT; Epistemonikos; Cochrane, CENTRAL, Campbell systematic reviews, Web of Science, SCI, SSCI, AHCI, CPCI-S, CPCI-SSH, and ESCI (in October 2022). Searches were updated in July 2024. Forward and backward citation searching was also undertaken in 2024 using CiteSearch, Scopus and Google Scholar. We included systematic reviews, randomised controlled trials (RCTs) and primary qualitative studies in the map that focused on the effectiveness and/or experience of any health or social care interventions for adults aged 80 years or more. All studies were independently screened for eligibility by two people at both title/abstract and full text stages. Interventions were categorised in line with the WHO definition of five domains that facilitate healthy ageing: building and maintaining intrinsic capacity, health services models and approaches, enabling environments and technologies, building and maintaining relationships and learning, growing and making decisions. Interventions could cut across multiple domains. The data extraction tool was developed on EPPI reviewer and was modified and tested through piloting and revising by the core team. The tool was informed by the research question and the structure of the map. As well as extracting data on population characteristics, intervention domain and sub-categories, we extracted additional data to enable filters, such as specific health conditions, and equity characteristics. Standardised tools were used to assess study quality for all studies: AMSTAR-2 for systematic reviews; Cochrane Risk of Bias tool (version 1) for RCTs; and the Wallace criteria for primary qualitative studies. Data extraction and quality appraisal were extracted by one person and checked by a second. We included 172 studies: 36 systematic reviews, 120 RCTs and 16 primary qualitative studies. Most of the systematic reviews were assessed as low or very low quality with only five assessed as moderate to high quality. Similarly, most of the RCTs were assessed to be at medium to high risk of bias, with only 27 RCTs assessed with an overall low risk of bias. Ten of the qualitative studies were assessed as high quality. Over a third of the studies (n = 67) in the map have been published since 2020. The majority of the evidence, over 90% (n = 157/172), was focused within the domain of building and maintaining intrinsic capacity, and within this domain, on either surgical and medical procedures (n = 75) or medicines and medical technologies (n = 54) in predominantly the cardiovascular, neuromuscular and digestive areas. Rehabilitation and behavioral interventions were also represented. Only a small number of studies focused on health conditions linked to ageing: frailty a focus of research in 14 studies, and falls in six studies. Only two studies addressed mental health therapies, and there were no studies focused on skin conditions, genitourinary health and or voice/speech conditions. The second most frequently represented domain was health service models and/or approaches (n = 38), predominantly relating to home visits (n = 15, all RCTs) and comprehensive geriatric assessment and integrated care (n = 5, all RCTs). The three intervention domains of enabling environments and technologies, building and maintaining relationships and learning, growing and making decisions were poorly represented in the evidence. The majority of studies measured physiological outcomes of health, such as measures of functional health, chronic health markers or symptoms, and adverse events; few studies assessed measures of well-being or psychosocial health. Sixteen studies reported on experiences of interventions, mostly from the experience of the older adult (n = 9) and were in relation to heart surgery and procedures, colon surgery, resuscitation, medicines review and preventative screening. Only 7% of outcomes in the map were in the psychological health and wellbeing category. Social health (including connectedness and participation) was not featured as an outcome in any studies. Studies were primarily conducted in Europe and Asia: these two regions representing over 75% of the evidence. There were several gaps evident in the map, including but not limited to, end-of-life care (including advance care planning) and healthcare delivery such as hospital-at-home and telehealth. Several potential research areas where synthesis might be valuable were also identified such as medicines optimisation, home visits, and specific health conditions such as osteoporosis treatments. As the worldwide population continues to age, it is increasingly important that we have evidence of appropriate effective interventions for those who have reached their 80s, 90s and beyond, a group often left out of trials. This evidence and gap map shows that currently there is a clear bias towards interventions orientated around a biomedical view of health focused on intrinsic capacity, and relatively little on the wider functional and psychosocial aspect of health, or on enabling environments, such as adaptations to health and care services, or models of care. There is also a clear need for more research to understand the experiences and preferences of interventions from adults aged 80 years or more. Research exclusively focussed on people aged over 80 targets medical treatments and surgical procedures, neglecting healthcare services or wellbeing, and much of it is poor quality. The Evidence and Gap Map (EGM) in brief: Most of the studies in people aged over 80 investigate medical procedures and treatments with a focus on basic health needs and the ability to function, with fewer studies about health and care services or wellbeing. What is this EGM about?: Our population is ageing, which means that people are living longer, and age-related illnesses such as arthritis, dementia and cancer are becoming more common. Studies investigating interventions (treatments, procedures, therapies and services) are often focused on people aged under 80, because those who are older are often excluded from taking part in trials. Therefore, the treatments that are considered best practice in a general population might not be the best option for people aged over 80. This EGM displays evidence of interventions from systematic reviews and randomised controlled trials (RCTs) and studies looking at experiences (qualitative studies) where the people being investigated were aged over 80. What is the aim of this EGM?: The aim of this EGM is to provide easy access to studies that investigate interventions for people aged over 80. The studies are grouped by types of interventions and outcomes. Overall, the EGM provides an overview of the volume and nature of evidence on interventions for this age group. What studies are included?: The EGM contains 172 studies investigating interventions for people aged over 80. The interventions are organized into five groups: building and maintaining intrinsic capacity (ability to function both physically and mentally), health services an/or approaches, enabling environments and technologies, building and maintaining relationships and learning, growing and making decisions. The EGM contains 36 systematic reviews, 120 RCTs and 16 qualitative studies. What are the main findings of this gap map?: Research in older people is becoming more common as the population ages. Over a third of studies (n = 67) in the map have been published since 2020. However, most of the research was moderate to poor quality. Most of the systematic reviews (n = 31) and RCTs (n = 93) were rated as low or very low quality. Only a small number of studies focused on health conditions linked to ageing, with frailty covered in 14 studies, and falls in 6 studies. Most of the studies (n = 157) were about building and maintaining intrinsic capacity, focusing on the treatment and/or prevention of diseases and health disorders. The categories with most studies were those that involved surgery (n = 75 studies), and those that involved medicines or medical devices (n = 54). Only two studies addressed mental health therapies, and no studies examined ‘end of life’, skin conditions, genitourinary health and or voice/speech conditions. Several studies (n = 38) examined health services and/or health approaches. Some of these (n = 15) were RCTs assessing the effectiveness of home visits and a smaller number (n = 5) assessed geriatric assessment. Surprisingly, there were no systematic reviews in the map covering those topics. The only systematic review in the health services category investigated admitting older adults with sepsis into intensive care units. Similarly, there were no systematic reviews in the categories of enabling environments and technologies and learning, growing and making decisions. The most common outcomes reported in the studies were physiological measures of health (such as blood cholesterol levels, or blood pressure), measures of physical function (such as strength, balance), chronic health symptoms and side effects and complications. Only 7% of outcomes in the map were in the psychological health and wellbeing category. Social health (including connectedness and participation) was not featured as an outcome in any studies. Sixteen studies reported on experiences of interventions, mostly from the experience of the older adult (n = 9) and were in relation to heart surgery and procedures, colon surgery, resuscitation, medicines review and preventative screening. What do the findings of the map mean?: This EGM provides information on systematic reviews, RCTs and qualitative studies that have examined the effectiveness of interventions for people aged over 80. This is important because people in older age groups are often excluded from research, meaning the interventions that are best for the general population might not be most suitable for them. While studies in people aged over 80 focus on basic health needs, older people are under-represented in studies about psychosocial aspects of health or enabling environments such as adaptations to health and care services. There is also a need for more studies examining how people aged over 80 experience treatments, therapies and services. How up-to-date is this EGM?: The EGM contains studies published up until July 2024.