Direct-to-consumer testing as consumer initiated testing: compromises to the testing process and opportunities for quality improvement.

Direct-to-consumer testing (DTCT) refers to commercial laboratory tests initiated by laypersons without the involvement of healthcare professionals. As this market grows in size and variety of products, a clear definition of DTCT to ground the conceptualization of their harms and benefits is needed. We describe how three different modalities of DTCT (home self-testing, self-sampled tests, and direct access tests) present caveats to the traditional testing process ('brain-to-brain loop'), and how this might differ between medical vs. non-medical laboratories. We make recommendations for ways to improve quality and reduce errors with respect to DTCT. The potential benefits and harms of DTCT will invariably depend on the context and situation of individual consumers and the types of tests involved. Importantly, implications for both consumers and the healthcare system should be considered, such as the effects on improving health outcomes and reducing unnecessary testing and use of clinical resources. 'Consumer initiation' must be a central defining characteristic of DTCT, to clearly demarcate the key drawbacks as well as opportunities of this type of testing from a laboratory specialists' perspective. The concept of 'consumer initiated testing' should also help define DTCT regulation, and provide a locus of efforts to support consumers as the main decision-makers in the purchasing and conducting of these tests in the absence of clinician gatekeeping.

Cystatin C or creatinine for pre-operative assessment of kidney function and risk of post-operative acute kidney injury: a secondary analysis of the METS cohort study.

Background: Post-operative acute kidney injury (PO-AKI) is a common surgical complication consistently associated with subsequent morbidity and mortality. Prior kidney dysfunction is a major risk factor for PO-AKI, however it is unclear whether serum creatinine, the conventional kidney function marker, is optimal in this population. Serum cystatin C is a kidney function marker less affected by body composition and might provide better prognostic information in surgical patients. Methods: This was a pre-defined, secondary analysis of a multi-centre prospective cohort study of pre-operative functional capacity. Participants were aged ≥40 years, undergoing non-cardiac surgery. We assessed the association of pre-operative estimated glomerular filtration rate (eGFR) calculated using both serum creatinine and serum cystatin C with PO-AKI within 3 days after surgery, defined by KDIGO creatinine changes. The adjusted analysis accounted for established AKI risk factors. Results: A total of 1347 participants were included (median age 65 years, interquartile range 56-71), of whom 775 (58%) were male. A total of 82/1347 (6%) patients developed PO-AKI. These patients were older, had higher prevalence of cardiovascular disease and related medication, were more likely to have intra-abdominal procedures, had more intraoperative transfusion, and were more likely to be dead at 1 year after surgery 6/82 (7.3%) vs 33/1265 (2.7%) (P = .038). Pre-operative eGFR was lower in AKI than non-AKI patients using both creatinine and cystatin C. When both measurements were considered in a single age- and sex-adjusted model, eGFR-Cysc was strongly associated with PO-AKI, with increasing risk of AKI as eGFR-Cysc decreased below 90, while eGFR-Cr was no longer significantly associated. Conclusions: Data from over 1000 prospectively recruited surgical patients confirms pre-operative kidney function as major risk factor for PO-AKI. Of the kidney function markers available, compared with creatinine, cystatin C had greater strength of association with PO-AKI and merits further assessment in pre-operative assessment of surgical risk.

Laparoscopic cholecystectomy versus conservative management for adults with uncomplicated symptomatic gallstones: the C-GALL RCT.

Background: Gallstone disease is a common gastrointestinal disorder in industrialised societies. The prevalence of gallstones in the adult population is estimated to be approximately 10-15%, and around 80% remain asymptomatic. At present, cholecystectomy is the default option for people with symptomatic gallstone disease. Objectives: To assess the clinical and cost-effectiveness of observation/conservative management compared with laparoscopic cholecystectomy for preventing recurrent symptoms and complications in adults presenting with uncomplicated symptomatic gallstones in secondary care. Design: Parallel group, multicentre patient randomised superiority pragmatic trial with up to 24 months follow-up and embedded qualitative research. Within-trial cost-utility and 10-year Markov model analyses. Development of a core outcome set for uncomplicated symptomatic gallstone disease. Setting: Secondary care elective settings. Participants: Adults with symptomatic uncomplicated gallstone disease referred to a secondary care setting were considered for inclusion. Interventions: Participants were randomised 1: 1 at clinic to receive either laparoscopic cholecystectomy or observation/conservative management. Main outcome measures: The primary outcome was quality of life measured by area under the curve over 18 months using the Short Form-36 bodily pain domain. Secondary outcomes included the Otago gallstones' condition-specific questionnaire, Short Form-36 domains (excluding bodily pain), area under the curve over 24 months for Short Form-36 bodily pain domain, persistent symptoms, complications and need for further treatment. No outcomes were blinded to allocation. Results: Between August 2016 and November 2019, 434 participants were randomised (217 in each group) from 20 United Kingdom centres. By 24 months, 64 (29.5%) in the observation/conservative management group and 153 (70.5%) in the laparoscopic cholecystectomy group had received surgery, median time to surgery of 9.0 months (interquartile range, 5.6-15.0) and 4.7 months (interquartile range 2.6-7.9), respectively. At 18 months, the mean Short Form-36 norm-based bodily pain score was 49.4 (standard deviation 11.7) in the observation/conservative management group and 50.4 (standard deviation 11.6) in the laparoscopic cholecystectomy group. The mean area under the curve over 18 months was 46.8 for both groups with no difference: mean difference -0.0, 95% confidence interval (-1.7 to 1.7); p-value 0.996; n = 203 observation/conservative, n = 205 cholecystectomy. There was no evidence of differences in quality of life, complications or need for further treatment at up to 24 months follow-up. Condition-specific quality of life at 24 months favoured cholecystectomy: mean difference 9.0, 95% confidence interval (4.1 to 14.0), p < 0.001 with a similar pattern for the persistent symptoms score. Within-trial cost-utility analysis found observation/conservative management over 24 months was less costly than cholecystectomy (mean difference -£1033). A non-significant quality-adjusted life-year difference of -0.019 favouring cholecystectomy resulted in an incremental cost-effectiveness ratio of £55,235. The Markov model continued to favour observation/conservative management, but some scenarios reversed the findings due to uncertainties in longer-term quality of life. The core outcome set included 11 critically important outcomes from both patients and healthcare professionals. Conclusions: The results suggested that in the short term (up to 24 months) observation/conservative management may be a cost-effective use of National Health Service resources in selected patients, but subsequent surgeries in the randomised groups and differences in quality of life beyond 24 months could reverse this finding. Future research should focus on longer-term follow-up data and identification of the cohort of patients that should be routinely offered surgery. Trial registration: This trial is registered as ISRCTN55215960. Funding: This award was funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment programme (NIHR award ref: 14/192/71) and is published in full in Health Technology Assessment; Vol. 28, No. 26. See the NIHR Funding and Awards website for further award information.

The C-GALL study assessed the benefits, in terms of symptoms, quality of life and costs, of cholecystectomy versus observation (conservative management: by the patient and general practitioner that might include dietary advice and pain management and surgery if needed). Four hundred and thirty-four patients with symptomatic gallstones were randomly allocated surgery or conservative management. The main symptom of ongoing bodily pain and some other quality-of-life measures were assessed over the next 2 years using postal questionnaires. After 2 years, 70% of those allocated to surgery had been operated on and 37% of the observation group either had an operation or were waiting for one. There was no difference in bodily pain or overall quality of life between the groups. However, participants in the surgery group reported fewer ongoing problems related to their gallstone disease or after surgery than those in the conservative management group. Surgery was, however, more costly than conservative management. The C-GALL study has shown that for some patients, a conservative management approach may be a sufficient and less costly way of managing their gallstone symptoms rather than going straight on the waiting list for surgery. More research is needed to identify which patients benefit most from surgery.