Lung cancer pathway inequalities for adults with severe mental health conditions: A mixed-methods analysis of barriers to screening and care pathways in South East London

Technical Summary: Lung Cancer Pathway Inequalities for Adults with Severe Mental Health Conditions

Problem Statement
Adults with severe mental health conditions (SMI), defined here as schizophrenia, schizoaffective disorder, bipolar disorder, or other psychoses, experience a 15–20-year mortality gap relative to the general population, with lung cancer being a significant contributor. While national cancer policy in the UK targets earlier diagnosis, existing pathways are largely designed around age-based eligibility and standard symptom presentation, failing to explicitly account for the needs of the SMI population. Previous evidence indicates a 64% higher all-cause mortality rate for adults with SMI following cancer diagnosis, attributed to delayed diagnosis, advanced stage at presentation, and reduced engagement. However, there is limited empirically grounded evidence describing how lung cancer pathways function in practice for this group, specifically where along the pathway inequalities emerge and how they are navigated by both staff and patients.

Methodology
This study employed an exploratory mixed-methods service evaluation design, conducted across the six boroughs of South East London (SEL). The research followed a sequential exploratory design, integrating quantitative analysis of routinely collected data with qualitative inquiry.

• Quantitative Component: Data were extracted from the Quality Outcomes Framework (QOF) SMI registers, the SMI Register, and Cancer Waiting Times (CWT) records for the period April 2023 to March 2024. The study analyzed approximately 26,365 individuals with SMI (1% of the registered population). Key metrics included smoking prevalence, lung cancer prevalence, Urgent Suspected Cancer (USC) referral rates, conversion to diagnosis, adherence to the 28-day Faster Diagnosis Standard (FDS), and appointment non-attendance (DNA) rates. Data were linked to local cancer activity dashboards, with small number suppression applied for privacy.
• Qualitative Component: The study utilized semi-structured interviews with 11 clinical staff (from primary care, mental health services, and emergency departments) and focus groups with 6 adults with lived experience of SMI who had accessed lung cancer pathways. Recruitment was co-designed with the Woolwich Service Users Project (WSUP) and experts by experience.
• Analysis: Quantitative data were analyzed using descriptive statistics. Qualitative data were transcribed and coded using a hybrid framework integrating the Health Equity Implementation Framework (HEIF), the Consolidated Framework for Implementation Research (CFIR 2.0), and selected domains of the Theoretical Domains Framework (TDF). Findings were integrated using a joint display approach to map quantitative indicators against qualitative themes.
• Stakeholder Engagement: A multidisciplinary steering group, including people with lived experience, guided the study design, interpretation, and validation of findings.

Key Results
The study identified a consistent pattern of inequality that accumulates across the diagnostic pathway rather than arising at a single point of failure.

• Risk and Prevalence: Lung cancer prevalence among adults with SMI was approximately double that of the general population (0.17% vs. 0.09%). Smoking prevalence in the SMI population was 27% (six-fold higher than the 4% in the non-SMI primary care population), with the highest rates in working-age adults.
• Referral and Detection Paradox: Despite USC referral rates being more than double in the SMI population (63 vs. 28 per 100,000), fewer cancers were detected via planned General Practice (GP) routes (11% vs. 20% in the general population). Conversion rates from referral to diagnosis were slightly lower for the SMI population.
• Diagnostic Timeliness: No SMI patients diagnosed with lung cancer via the USC pathway met the 28-day Faster Diagnosis Standard (FDS), compared to 21% of the non-SMI population. Overall FDS performance for the SMI population was 76% versus 84% in the general population.
• Engagement: Appointment non-attendance (DNA) rates were more than double for the SMI population (6% vs. 3%).
• Screening Eligibility: A significant proportion of the SMI population falls outside the current NHS Lung Cancer Screening (LCS) age criteria (55–74), despite high smoking prevalence and risk accumulation in younger working-age groups.
• Qualitative Barriers:
  • Individual Level: Stigma, fear of diagnosis, low health literacy, and competing daily survival needs (housing, food insecurity) led to symptom concealment and delayed help-seeking.
  • Service Level: Rigid non-attendance policies (referral closure after missed appointments), complex correspondence, and lack of continuity (e.g., loss of named clinicians) disproportionately disrupted pathway navigation.
  • System Level: Fragmented coordination between physical and mental health services, diagnostic overshadowing (attributing physical symptoms to mental health causes), and unclear accountability for care continuity.
• Enablers: Trusting relationships with named clinicians, continuity of care, support workers, and adaptive clinical practices (e.g., flexible appointment scheduling) were identified as critical facilitators, though these were often informal and inconsistently available.

Key Contributions
This study provides a granular, empirically grounded description of lung cancer pathway performance for adults with SMI, moving beyond mortality statistics to identify specific mechanisms of inequality.

1. Pathway Accumulation: It demonstrates that inequality is cumulative, compounding at each transition point from symptom recognition to diagnosis and treatment.
2. Mechanism Identification: It identifies specific barriers such as diagnostic overshadowing, rigid administrative protocols, and the "one-size-fits-all" nature of screening programs that exclude high-risk younger SMI adults.
3. Data Integration: By integrating quantitative pathway metrics with qualitative insights from staff and patients, the study explains why high referral rates do not translate into timely diagnoses.
4. Actionable Framework: The findings are organized using implementation science frameworks (CFIR, HEIF) to provide a structured basis for intervention.

Significance and Claims
The paper claims that addressing lung cancer inequalities for adults with SMI requires proportionate adaptations within existing cancer pathways rather than solely focusing on increasing referral volumes. The study argues that:

• Measurement is Critical: Current Cancer Waiting Time (CWT) metrics do not routinely stratify by SMI status, rendering these disparities invisible in standard performance reporting. The authors propose the introduction of an SMI flag in cancer tracking systems to improve visibility and accountability.
• Systemic Redesign: Interventions must address the entire pathway, including reducing reliance on rigid non-attendance policies, improving coordination between mental and physical health services, and adapting communication methods.
• Screening Gaps: The current LCS age criteria create a structural gap for younger, high-risk SMI adults, necessitating complementary prevention and risk identification strategies (e.g., embedding cessation support in mental health settings).
• Co-Production: The study validates the necessity of co-designing pathways with people with lived experience to ensure accessibility and trust.

The authors conclude that without targeted, system-level interventions and routine reporting of outcomes stratified by SMI status, the mortality gap for this population will persist. The study offers practical, co-produced recommendations for clinicians and system leaders to improve early diagnosis and engagement.