Frailty is a multidimensional syndrome of reduced physiological reserve and heightened vulnerability to stressors. Frailty is common among older adults and linked to adverse outcomes including disability, hospitalisation and death. Infections are common in older populations and remain a major cause of morbidity and death. Although it has been suggested that infections influence frailty development and progression (via inflammatory and functional mechanisms), evidence from longitudinal studies is inconsistent. Therefore, we aim to assess longitudinal associations between infections and frailty in adults.

We will conduct a systematic review of observational cohort and case-control studies examining associations between infections and frailty in adults. We will search MEDLINE, Embase and Global Health from 2001 to February 2026 without language restrictions. Two reviewers will independently screen titles and abstracts and subsequently assess full texts for eligibility. Data will be extracted using a standardised data extraction form. Risk of bias will be assessed using a customised domain-based tool based on the Risk Of Bias In Non-randomised Studies of Exposures (ROBINS-E) framework. We will initially narratively synthesise our findings. Where studies are sufficiently homogeneous, we will undertake random effects meta-analysis. We will assess the certainty of the evidence using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach.

Ethical approval is not required for a systematic review. Results of the review will be published in a peer-reviewed journal and disseminated through conferences.

CRD420261299590.

Acute pain is an expected symptom for adolescents after outpatient surgery. In the USA, postoperative analgesic regimens frequently include prescription opioids. Increasing attention from clinicians, patients and other healthcare leaders has been directed toward non-opioid strategies, such as combining non-steroidal anti-inflammatory drugs (NSAIDs) plus acetaminophen, as potential first-line options for managing postoperative pain. However, the effectiveness and safety of home regimens that include versus exclude opioids for adolescents are unclear. The Comparing Analgesic Regimen Effectiveness and Safety after surgery for Kids study evaluates the effectiveness and safety of NSAIDs plus acetaminophen alone (NSAID regimen) versus NSAIDs and acetaminophen plus a low-dose opioid regimen (opioid regimen).

This study is a pragmatic, multicentre randomised controlled clinical trial recruiting 900 patients aged 12–20 years undergoing three common outpatient surgeries (tonsillectomy, laparoscopic cholecystectomy, knee arthroscopy) across four health systems. We will recruit patients prior to surgery and individuals will be randomised 1:1 with stratification to receive prescriptions for either the NSAID regimen or the opioid regimen. The primary effectiveness outcome is patient-reported pain intensity, while the primary safety outcome is adverse medication-related symptoms both assessed over the first 2 weeks after surgery. Secondary outcomes include quality of recovery, healthcare-related quality of life and rates of problematic substance use and chronic prescription opioid use, assessed up to 1 year after surgery.

The study incorporates stakeholder collaboration, including patient partners, surgeons, professional organisations., and health insurance payors, to ensure ethical conduct and relevance. This study is overseen by a single institutional review board with certificate of confidentiality. Findings will be disseminated through academic publications, conferences and community outreach to inform patients, parents, surgical teams and policymakers about optimal pain management strategies for adolescents after surgery.

NCT06671002.