Cancer in general practice research priorities in Australia.

BACKGROUND AND OBJECTIVES: The Primary Care Collaborative Cancer Clinical Trials Group (PC4) is funded by Cancer Australia to support the development of new cancer in primary care research. We undertook a research prioritisation exercise to identify cancer research priorities in Australian general practice. METHOD: We adapted the nominal group technique, including a literature search and stakeholder survey. An expert group from the Primary Care Collaborative Cancer Clinical Trials Group consolidated and ranked priorities. A second stakeholder survey reviewing the top 50 priorities informed a final prioritisation workshop. RESULTS: Overall, 311 priorities were identified across the cancer continuum. Nearly one-third of priorities were related to cancer survivorship and included strategies to detect recurrence, behavioural interventions and tools to assess physical and psychosocial aspects of survivorship. Prevention/early detection comprised 43.4% of priorities. Palliative care produced the least priorities (9.6%). Cross cutting research priorities (15.1%) included quality and models of care. DISCUSSION: This is the first study to identify cancer research priorities for general practice in Australia. It could be used to inform the development of targeted research and funding to improve the care and outcomes for Australians affected by cancer.

What are the mechanisms underlying the delivery of survivorship care information in Australia? A realist review.

OBJECTIVE: Quality survivorship information is an essential component of cancer care. However, survivors often report not receiving this information and healthcare professionals report limited practical guidance on how to effectively deliver survivorship information. Therefore, this study used realist review methods to identify mechanisms reported within the published literature for communicating survivorship information and to understand the contextual factors that make these mechanisms effective. METHODS: Full-text papers published in CINAHL, PubMed, Web of Science, Scopus, Cochrane Library, and Academic Search Ultimate were included. Studies included in this review were conducted in Australia between January 2006 and December 2023, and reported on how information regarding survivorship care was communicated to adult cancer survivors living in the community. This review utilized realist methodologies: text extracts were converted to if-then statements used to generate context-mechanism-outcome theories. RESULTS: Fifty-one studies were included and six theories for mechanisms that underpin the effective delivery of survivorship information were formed. These include: (1) tailoring information based on the survivors' background, (2) enhancing communication among providers, (3) employing dedicated survivorship staff, (4) providing survivorship training, (5) reducing the burden on survivors to navigate their care, and (6) using multiple modalities to provide information. CONCLUSIONS: Findings can inform practical guidance for how survivorship care information is best delivered in practice. Clinicians can apply this guidance to improve their individual interactions with cancer survivors, as can policymakers to develop healthcare systems and procedures that support effective communication of cancer survivorship information.

Should I Take Aspirin? (SITA): RCT of a decision aid for cancer chemoprevention.

Background Australian guidelines recommend that all people aged 50-70 years old consider taking low-dose aspirin to reduce the risk of colorectal cancer (CRC). Aim To determine the effect of a consultation with a researcher in general practice using a decision aid about taking low-dose aspirin to prevent CRC on informed decision-making and low-dose aspirin uptake compared to a general CRC prevention brochure. Design and Setting Individually randomised controlled trial in six general practices in Victoria, Australia, from October 2020 to March 2021. Method Patients aged 50-70 years attending a general practitioner (GP) were recruited consecutively. The intervention was a consultation using a decision aid to discuss taking aspirin to reduce CRC risk; control consultations discussed reducing CRC risk generally. The self-reported co-primary outcomes were informed choices about taking aspirin at one month and low-dose aspirin uptake at six months. Results 261 participants (86% of eligible patients) were randomised into trial arms (129 intervention, 132 control). 17.7% (20/113) of intervention and 7.6% (9/118) control participants reported making an informed choice at one month, an estimated 9.1% (95% CI 0.29% to 18.5) between-arm difference in proportions [odds ratio (OR) 2.47 (97.5% CI:0.94 to 6.52) p=0.074]. The proportions of individuals who reported using aspirin at six months were: 10.2% (12/118) intervention vs 13.8% (16/116) control (estimated between-arm difference: -4.0% (95% CI: -13.5 to 5.5); [OR= 0.68 (97.5% CI:0.27 to 1.70), p= 0.692]. Conclusion The decision aid improved informed decision-making; but has little effect on long-term regular use of aspirin to reduce CRC risk.

Clinical activity in general practice prior to sarcoma diagnosis: Australian cohort study.

Background Increased time-to-diagnosis in sarcoma is associated with poor prognosis and patient outcomes. Research is needed to identify if opportunities to expedite the diagnosis of sarcoma in general practice (GP) exist. Aim To examine pre-diagnostic GP clinical activity prior to sarcoma diagnosis. Design and Setting An Australian retrospective cohort study using hospital registry data (Australian Comprehensive Cancer Outcomes and Research Database) linked to two primary care datasets (Patron and MedicineInsight). Method The frequency of GP healthcare utilisation events (GP attendances, prescriptions, blood test and imaging requests) were compared in 377 soft tissue sarcoma (STS) and 64 bone sarcoma (BS) patients in the year pre-diagnosis. Poisson regression models were used to calculate monthly incidence rates and rate ratios (IRR) for the 24 months pre-diagnosis and estimate inflection points for when healthcare use starts to increase from baseline. Results In the six months pre-diagnosis sarcoma patients had a median of 3-4 GP attendances, a third had a GP imaging request (33% BS and 36% STS), and one in five had multiple imaging requests (19% BS and 21% STS). GP imaging requests progressively increased up to 8-fold from 6 months prior to sarcoma diagnosis (IRR 8.43 95%CI 3.92-18.15, p<0.001) and GP attendances increased from 3 months pre-diagnosis. Conclusion Sarcoma patients have increased GP clinical activity from 6 months pre-diagnosis, indicating a diagnostic window where potential opportunities exist for earlier diagnosis. Interventions to help identify patients and promote appropriate use of imaging and direct specialist centre referrals could improve earlier diagnosis and patient outcomes.

Discussions with patients about referral pathways and costs in the diagnosis and treatment of colorectal cancer in Victoria, Australia.

BACKGROUND AND OBJECTIVES: Colorectal cancer (CRC) survival in Australia differs by health insurance status, but why this occurs is uncertain. There are growing concerns about out-of-pocket healthcare costs. We examined patient experiences of referral pathways to diagnosis and treatment of CRC in Victoria, Australia, and discussions about costs, comparing public, private and mixed healthcare system users. METHOD: Semistructured telephone interviews were conducted with 16 purposively sampled, English-speaking patients aged ≥40 years with CRC. Interviews were recorded, transcribed and analysed thematically. RESULTS: Private patients described greater out-of-pocket expenses balanced by greater choice of provider and access. Public patients perceived limited choice in their diagnostic or treatment provider, although some considered switching systems. Patients trusted their general practitioner or specialist for referrals. Discussions about costs did not meet guideline recommendations. DISCUSSION: There are limited opportunities for informed decision making about public versus private care for cancer diagnosis and treatment, which could contribute to inequalities in outcomes.

Patient Preferences for Investigating Cancer-Related Symptoms in Australian General Practice: A Discrete Choice Experiment.

BACKGROUND: Striking the right balance between early cancer diagnosis and the risk of excessive testing for low-risk symptoms is of paramount importance. Patient-centred care must also consider patient preferences for testing. AIM: To investigate diagnostic testing preferences of the Australian public for symptoms associated with oesophagogastric (OG), bowel, or lung cancer. DESIGN AND SETTING: One of three discrete choice experiments (DCEs) related to either OG, bowel, or lung cancer were administered to a nationally representative sample of Australians aged 40 and above. METHODS: Each DCE comprised three scenarios with symptom positive predictive values (PPVs) for undiagnosed cancer ranging from 1% to 3%. The numerical risk was concealed from participants. DCE attributes encompassed the testing strategy, GP familiarity, test and result waiting times, travel duration, and test cost. Preferences were estimated using conditional and mixed logit models. RESULTS: A total of 3013 individuals participated in one of three DCEs: OG (n=1004), Bowel (n=1006), and Lung (n=1003). Preferences were chiefly driven by waiting time, test cost followed by the test type. There was preference for more invasive tests. When confronted with symptoms carrying an extremely low risk (symptom PPV of 1% or less), participants were more inclined to abstain from testing. CONCLUSIONS: Access-related factors, particularly waiting times and testing costs, emerged as the most pivotal elements influencing preferences, underscoring the substantial impact of these systemic factors on patient choices regarding investigations.

Primary care practice-based interventions and their effect on participation in population-based cancer screening programs: a systematic narrative review.

AIM: To provide a systematic synthesis of primary care practice-based interventions and their effect on participation in population-based cancer screening programs. BACKGROUND: Globally, population-based cancer screening programs (bowel, breast, and cervical) have sub-optimal participation rates. Primary healthcare workers (PHCWs) have an important role in facilitating a patient's decision to screen; however, barriers exist to their engagement. It remains unclear how to best optimize the role of PHCWs to increase screening participation. METHODS: A comprehensive search was conducted from January 2010 until November 2023 in the following databases: Medline (OVID), EMBASE, and CINAHL. Data extraction, quality assessment, and synthesis were conducted. Studies were separated by whether they assessed the effect of a single-component or multi-component intervention and study type. FINDINGS: Forty-nine studies were identified, of which 36 originated from the USA. Fifteen studies were investigations of single-component interventions, and 34 studies were of multi-component interventions. Interventions with a positive effect on screening participation were predominantly multi-component, and most included combinations of audit and feedback, provider reminders, practice-facilitated assessment and improvement, and patient education across all screening programs. Regarding bowel screening, provision of screening kits at point-of-care was an effective strategy to increase participation. Taking a 'whole-of-practice approach' and identifying a 'practice champion' were found to be contextual factors of effective interventions.The findings suggest that complex interventions comprised of practitioner-focused and patient-focused components are required to increase cancer screening participation in primary care settings. This study provides novel understanding as to what components and contextual factors should be included in primary care practice-based interventions.

Increasing bowel cancer screening using SMS in general practice: the SMARTscreen cluster randomised trial.

BACKGROUND: Australia has one of the highest incidences of colorectal cancer (CRC) worldwide. The Australian National Bowel Cancer Screening Program (NBCSP) is a best-practice, organised screening programme, but uptake is low (40.9%) and increasing participation could reduce morbidity and mortality associated with CRC. Endorsement by GPs is strongly associated with increasing screening uptake. AIM: This study (SMARTscreen) aimed to test whether a multi-intervention short message service (SMS) sent by general practices to 50-60-year-old patients who were due to receive the NBCSP kit would increase NBCSP uptake, by comparing it with usual care. DESIGN AND SETTING: A stratified cluster randomised controlled trial was undertaken, involving 21 Australian general practices in Western Victoria, Australia. METHOD: For intervention practices, people due to receive the NBCSP kit within a 6-month study period were sent an SMS just before receiving the kit. The SMS included a personalised message from the person's general practice endorsing the kit, a motivational narrative video, an instructional video, and a link to more information. Control practices continued with usual care, comprising at-home testing with a faecal immunochemical test (FIT) through the NBCSP. The primary outcome was the between-arm percentage difference in uptake of FIT screening within 12 months from randomisation, which was estimated using generalised linear model regression. RESULTS: In total, 39.2% (1143/2914) of people in 11 intervention practices and 23.0% (583/2537) of people in 10 control practices had a FIT result in their electronic health records - a difference of 16.5% (95% confidence interval = 2.02 to 30.9). CONCLUSION: The SMS intervention increased NBCSP kit return in 50-60-year-old patients in general practice. This finding informed a larger trial - SMARTERscreen - to test this intervention in a broader Australian population.

Colorectal cancer survivors' experiences and views of shared and telehealth models of survivorship care: A qualitative study.

OBJECTIVES: The number of colorectal cancer (CRC) survivors is increasing and current models of survivorship care are unsustainable. There is a drive to implement alternative models of care including shared care between general practitioners (GPs) and hospital-based providers. The primary objective of this study was to explore perspectives on facilitators and barriers to shared care. The secondary objective was to explore experiences of telehealth-delivered care. METHOD: Qualitative data were collected via semi-structured interviews with participants in the Shared Care for Colorectal Cancer Survivors (SCORE) randomised controlled trial. Interviews explored patient experiences of usual and shared survivorship care during the SCORE trial. In response to the COVID pandemic, participant experiences of telehealth appointments were also explored. Interviews were recorded and transcribed for thematic analysis. RESULTS: Twenty survivors of CRC were interviewed with an even number in the shared and usual care arms; 14 (70%) were male. Facilitators to shared care included: good relationships with GPs; convenience of GPs; good communication between providers; desire to reduce public health system pressures. Barriers included: poor communication between clinicians; inaccessibility of GPs; beliefs about GP capacity; and a preference for follow-up care with the hospital after positive treatment experiences. Participants also commonly expressed a preference for telehealth-based follow-up when there was no need for a clinical examination. CONCLUSIONS: This is one of few studies that have explored patient experiences with shared and telehealth-based survivorship care. Findings can guide the implementation of these models, particularly around care coordination, communication, preparation, and personalised pathways of care.

SCORE: a randomised controlled trial evaluating shared care (general practitioner and oncologist) follow-up compared to usual oncologist follow-up for survivors of colorectal cancer.

Background: SCORE is the first randomised controlled trial (RCT) to examine shared oncologist and general practitioner (GP) follow-up for survivors of colorectal cancer (CRC). SCORE aimed to show that shared care (SC) was non-inferior to usual care (UC) on the EORTC QLQ-C30 Global Health Status/Quality of Life (GHQ-QoL) scale to 12 months. Methods: The study recruited patients from five public hospitals in Melbourne, Australia between February 2017 and May 2021. Patients post curative intent treatment for stage I-III CRC underwent 1:1 randomisation to SC and UC. SC replaced two oncologist visits with GP visits and included a survivorship care plan and primary care management guidelines. Assessments were at baseline, 6 and 12 months. Difference between groups on GHQ-QoL to 12 months was estimated from a mixed model for repeated measures (MMRM), with a non-inferiority margin (NIM) of -10 points. Secondary endpoints included quality of life (QoL); patient perceptions of care; costs and clinical care processes (CEA tests, recurrences). Registration ACTRN12617000004369p. Findings: 150 consenting patients were randomised to SC (N = 74) or UC (N = 76); 11 GPs declined. The mean (SD) GHQ-QoL scores at 12 months were 72 (20.2) for SC versus 73 (17.2) for UC. The MMRM mean estimate of GHQ-QoL across the 6 month and 12 month follow-up was 69 for SC and 73 for UC, mean difference -4.0 (95% CI: -9.0 to 0.9). The lower limit of the 95% CI did not cross the NIM. There was no clear evidence of differences on other QoL, unmet needs or satisfaction scales. At 12 months, the majority preferred SC (40/63; 63%) in the SC group, with equal preference for SC (22/62; 35%) and specialist care (22/62; 35%) in UC group. CEA completion was higher in SC. Recurrences similar between arms. Patients in SC on average incurred USD314 less in health costs versus UC patients. Interpretation: SC seems to be an appropriate and cost-effective model of follow-up for CRC survivors. Funding: Victorian Cancer Agency and Cancer Australia.

Estimating the contribution of subclinical tuberculosis disease to transmission: An individual patient data analysis from prevalence surveys.

Background: Individuals with bacteriologically confirmed pulmonary tuberculosis (TB) disease who do not report symptoms (subclinical TB) represent around half of all prevalent cases of TB, yet their contribution to Mycobacterium tuberculosis (Mtb) transmission is unknown, especially compared to individuals who report symptoms at the time of diagnosis (clinical TB). Relative infectiousness can be approximated by cumulative infections in household contacts, but such data are rare. Methods: We reviewed the literature to identify studies where surveys of Mtb infection were linked to population surveys of TB disease. We collated individual-level data on representative populations for analysis and used literature on the relative durations of subclinical and clinical TB to estimate relative infectiousness through a cumulative hazard model, accounting for sputum-smear status. Relative prevalence of subclinical and clinical disease in high-burden settings was used to estimate the contribution of subclinical TB to global Mtb transmission. Results: We collated data on 414 index cases and 789 household contacts from three prevalence surveys (Bangladesh, the Philippines, and Viet Nam) and one case-finding trial in Viet Nam. The odds ratio for infection in a household with a clinical versus subclinical index case (irrespective of sputum smear status) was 1.2 (0.6-2.3, 95% confidence interval). Adjusting for duration of disease, we found a per-unit-time infectiousness of subclinical TB relative to clinical TB of 1.93 (0.62-6.18, 95% prediction interval [PrI]). Fourteen countries across Asia and Africa provided data on relative prevalence of subclinical and clinical TB, suggesting an estimated 68% (27-92%, 95% PrI) of global transmission is from subclinical TB. Conclusions: Our results suggest that subclinical TB contributes substantially to transmission and needs to be diagnosed and treated for effective progress towards TB elimination. Funding: JCE, KCH, ASR, NS, and RH have received funding from the European Research Council (ERC) under the Horizon 2020 research and innovation programme (ERC Starting Grant No. 757699) KCH is also supported by UK FCDO (Leaving no-one behind: transforming gendered pathways to health for TB). This research has been partially funded by UK aid from the UK government (to KCH); however, the views expressed do not necessarily reflect the UK government's official policies. PJD was supported by a fellowship from the UK Medical Research Council (MR/P022081/1); this UK-funded award is part of the EDCTP2 programme supported by the European Union. RGW is funded by the Wellcome Trust (218261/Z/19/Z), NIH (1R01AI147321-01), EDTCP (RIA208D-2505B), UK MRC (CCF17-7779 via SET Bloomsbury), ESRC (ES/P008011/1), BMGF (OPP1084276, OPP1135288 and INV-001754), and the WHO (2020/985800-0).

Reevaluating progression and pathways following Mycobacterium tuberculosis infection within the spectrum of tuberculosis.

Traditional understanding of the risk of progression from Mycobacterium tuberculosis (Mtb) infection to tuberculosis (TB) overlooks diverse presentations across a spectrum of disease. We developed a deterministic model of Mtb infection and minimal (pathological damage but not infectious), subclinical (infectious but no reported symptoms), and clinical (infectious and symptomatic) TB, informed by a rigorous evaluation of data from a systematic review of TB natural history. Using a Bayesian approach, we calibrated the model to data from historical cohorts that followed tuberculin-negative individuals to tuberculin conversion and TB, as well as data from cohorts that followed progression and regression between disease states, disease state prevalence ratios, disease duration, and mortality. We estimated incidence, pathways, and 10-y outcomes following Mtb infection for a simulated cohort. Then, 92.0% (95% uncertainty interval, UI, 91.4 to 92.5) of individuals self-cleared within 10 y of infection, while 7.9% (95% UI 7.4 to 8.5) progressed to TB. Of those, 68.6% (95% UI 65.4 to 72.0) developed infectious disease, and 33.2% (95% UI 29.9 to 36.4) progressed to clinical disease. While 98% of progression to minimal disease occurred within 2 y of infection, only 71% and 44% of subclinical and clinical disease, respectively, occurred within this period. Multiple progression pathways from infection were necessary to calibrate the model and 49.5% (95% UI 45.6 to 53.7) of those who developed infectious disease undulated between disease states. We identified heterogeneous pathways across disease states after Mtb infection, highlighting the need for clearly defined disease thresholds to inform more effective prevention and treatment efforts to end TB.

Should I take aspirin? A qualitative study on the implementation of a decision aid on taking aspirin for bowel cancer prevention.

OBJECTIVES: Australian guidelines recommend 50-70 years consider taking aspirin to reduce their bowel cancer risk. We trialled a decision aid in general practice to facilitate the implementation of these guidelines into clinical practice. This publication reports on the qualitative results from the process evaluation of the trial. We aimed to explore general practitioners' (GPs) and their patients' approach to shared decision-making (SDM) about taking aspirin to prevent bowel cancer and how the decision aids were used in practice. METHODS: Semistructured interviews were conducted with 17 participants who received the decision aid and 12 GPs who participated in the trial between June and November 2021. The interviews were coded inductively, and emerging themes were mapped onto the Revised Programme Theory for SDM. RESULTS: The study highlighted the dynamics of SDM for taking aspirin to prevent bowel cancer. Some participants discussed the decision aid with their GPs as advised prior to taking aspirin, others either took aspirin or dismissed it outright without discussing it with their GPs. Notably, participants' trust in their GPs, and participants' diverse worldviews played pivotal roles in their decisions. Although the decision aid supported SDM for some, it was not always prioritised in a consultation. This was likely impacted during the trial period as the COVID-19 pandemic was the focus for general practice. CONCLUSION: In summary, this study illustrated the complexities of SDM through using a decision aid in general practice to implement the guidelines for low-dose aspirin to prevent bowel cancer. While the decision aid prompted some participants to speak to their GPs, they were also heavily influenced by their unwavering trust in the GPs and their different worldviews. In the face of the COVID-19 pandemic, SDM was not highly prioritised. This study provides insights into the implementation of guidelines into clinical practice and highlights the need for ongoing support and prioritisation of cancer prevention in general practice consultations. TRIAL REGISTRATION NUMBER: ACTRN12620001003965.

SMARTERscreen protocol: a three-arm cluster randomised controlled trial of patient SMS messaging in general practice to increase participation in the Australian National Bowel Cancer Screening Program.

BACKGROUND: Australia persistently has one of the highest rates of colorectal cancer (CRC) in the world. Australia's National Bowel Cancer Screening Program (NBCSP) sends a biennial Faecal Immunochemical Test (FIT)-the 'NBCSP kit'-to everyone eligible for the programme between 50 and 74 years old; however, participation in the programme is low, especially in the 50- to 60-year-old age group. Our previous efficacy trial ('SMARTscreen') demonstrated an absolute increase in uptake of 16.5% (95% confidence interval = 2.02-30.9%) for people sent an SMS with motivational and instructional videos, from their general practice prior to receiving their NBCSP kit, compared to those receiving usual care. Building on the strengths of the SMARTscreen trial and addressing limitations, the 'SMARTERscreen' trial will test the effect on participation in the NBCSP of sending either an SMS only or an SMS with online video material to general practice patients due to receive their NBCSP compared to 'usual care'. METHODS: SMARTERscreen is a three-arm stratified cluster randomised controlled trial involving 63 general practices in two states in Australia. Eligible patients are patients who are aged 49-60 years and due to receive their NBCSP kit within the next 2 weeks during the intervention period. General practices will be equally randomised to three trial arms (21:21:21, estimated average 260 patients/practice). The two interventions include (i) an SMS with an encouraging message from their general practice or (ii) the same SMS with weblinks to additional motivational and instructional videos. The control arm will receive 'usual care'. Using the intention-to-treat approach, primary analysis will estimate the three pair-wise between-arm differences in the proportion of eligible patients who participate in the NBCSP within 6 months of when their kit is sent, utilising screening data from the Australian National Cancer Screening Register (NCSR). Patient intervention adherence to the interventions will also be evaluated. Findings will be incorporated into the Policy1-Bowel microsimulation model to estimate the long-term health benefits and cost-effectiveness of the interventions. DISCUSSION: SMARTERscreen will provide high-level evidence determining whether an SMS or an SMS with web-based material sent to general practice patients prior to receiving their NBCSP kit increases participation in bowel cancer screening. TRIAL REGISTRATION: Australian New Zealand Clinical Trials Registry ACTRN12623000036617. Registered on 13 January 2023. Trial URL: https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=385119&isClinicalTrial=False.

A systematic review of smartphone applications for cancer survivors.

PURPOSE: Mobile phone applications are positioned to support, educate, and empower cancer survivors during post-treatment care. We undertook a review to assess the utility of such smartphone applications; determine whether their use correlates with improved quality of life and other self-reported outcomes; and understand the feasibility of integrating mobile apps into routine follow-up care. METHODS: MEDLINE, EMBASE, Emcare, and PsycINFO databases were searched for studies evaluating apps that addressed at least one of the five Cancer Survivorship Care Quality Framework (CSCQF) domains published up until December 2021. Studies were narratively synthesized. Implementation barriers and facilitators were mapped against the Technology Acceptance Model. RESULTS: Twenty-three primary studies were included in this review. Only three randomized controlled trials (RCTs) were identified. Studies generally found mobile apps to be feasible, acceptable, and well-placed to support survivorship care. Health promotion was the most predominant CSCQF domain with apps primarily aiming to support exercise and dietary changes. The domains of monitoring for cancer recurrence (n=5) and management of co-morbidities (n=1) were underrepresented. Barriers to app use included greater time since active treatment, lack of familiarity with technology, and content not tailored to the user. CONCLUSIONS: Mobile apps are both feasible and acceptable in supporting the transition between active treatment and follow-up care. However, understanding the utility of such apps is limited by the low number of RCTs. IMPLICATIONS FOR CANCER SURVIVORS: Mobile apps have the potential to be useful support tools for patients post-treatment. However, given the number of apps developed, targeted, and available to cancer survivors, practical guidance to help cancer survivors choose appropriate apps is needed.

The effect of time before diagnosis and treatment on colorectal cancer outcomes: systematic review and dose-response meta-analysis.

BACKGROUND: This systematic review and meta-analysis aimed to evaluate existing evidence on the relationship between diagnostic and treatment intervals and outcomes for colorectal cancer. METHODS: Four databases were searched for English language articles assessing the role of time before initial treatment in colorectal cancer on any outcome, including stage and survival. Two reviewers independently screened articles for inclusion and data were synthesised narratively. A dose-response meta-analysis was performed to examine the association between treatment interval and survival. RESULTS: One hundred and thirty papers were included in the systematic review, eight were included in the meta-analysis. Forty-five different intervals were considered in the time from first symptom to treatment. The most common finding was of no association between the length of intervals on any outcome. The dose-response meta-analysis showed a U-shaped association between the treatment interval and overall survival with the nadir at 45 days. CONCLUSION: The review found inconsistent, but mostly a lack of, association between interval length and colorectal cancer outcomes, but study design and quality were heterogeneous. Meta-analysis suggests survival becomes increasingly poorer for those commencing treatment more than 45 days after diagnosis. REGISTRATION: This review was registered, and the protocol is available, in PROSPERO, the international database of systematic reviews, with the registration ID CRD42021255864.

Is neglect of self-clearance biasing TB vaccine impact estimates?

BACKGROUND: Mathematical modelling has been used extensively to estimate the potential impact of new tuberculosis vaccines, with the majority of existing models assuming that individuals with Mycobacterium tuberculosis (Mtb) infection remain at lifelong risk of tuberculosis disease. Recent research provides evidence that self-clearance of Mtb infection may be common, which may affect the potential impact of new vaccines that only take in infected or uninfected individuals. We explored how the inclusion of self-clearance in models of tuberculosis affects the estimates of vaccine impact in China and India. METHODS: For both countries, we calibrated a tuberculosis model to a scenario without self-clearance and to various scenarios with self-clearance. To account for the current uncertainty in self-clearance properties, we varied the rate of self-clearance, and the level of protection against reinfection in self-cleared individuals. We introduced potential new vaccines in 2025, exploring vaccines that work in uninfected or infected individuals only, or that are effective regardless of infection status, and modelling scenarios with different levels of vaccine efficacy in self-cleared individuals. We then estimated the relative disease incidence reduction in 2050 for each vaccine compared with the no vaccination scenario. FINDINGS: The inclusion of self-clearance increased the estimated relative reductions in incidence in 2050 for vaccines effective only in uninfected individuals, by a maximum of 12% in China and 8% in India. The inclusion of self-clearance increased the estimated impact of vaccines only effective in infected individuals in some scenarios and decreased it in others, by a maximum of 14% in China and 15% in India. As would be expected, the inclusion of self-clearance had minimal impact on estimated reductions in incidence for vaccines that work regardless of infection status. INTERPRETATIONS: Our work suggests that the neglect of self-clearance in mathematical models of tuberculosis vaccines does not result in substantially biased estimates of tuberculosis vaccine impact. It may, however, mean that we are slightly underestimating the relative advantages of vaccines that work in uninfected individuals only compared with those that work in infected individuals.