Effect of Lipid-Testing Interval on Stoke Risk among Newly Diagnosed Dyslipidemia Patients Initiated on Statins

(1) Background: Although current guidelines recommend regular lipid testing for dyslipidemia patients, the effectiveness of regular lipid profile monitoring in clinical outcomes is unclear. (2) Methods: We assessed 64,664 newly diagnosed dyslipidemia patients from the Korean National Health Insurance Service Health Screening Cohort from 2003–2011 For lipid-testing frequency from all admission and outpatient records for 3 years after diagnosis. Participants were followed until 31 December 2015 for stroke. We used Cox regression analysis to determine the adjusted hazard ratio (aHR) for stroke according to lipid-testing interval. (3) Results: Compared to patients with lipid-testing intervals of ≤6 months, patients with >6 to ≤12 (aHR 1.32, 95% confidence interval (CI) 1.08–1.61), >12 to ≤18 (aHR 1.48, 95% CI 1.20–1.82), and >18 (aHR 1.54, 95% CI 1.25–1.90) month testing intervals had elevated risk of total stroke (p for trend <0.001). A significant association existed between lipid-testing interval and total and ischemic stroke risk in the >6 to ≤12 (aHR 1.62, 95% CI 1.19–2.21), >12 to ≤18 (aHR 1.87, 95% CI 1.36–2.58), and >18 (aHR 1.79, 95% CI 1.30–2.48) month interval groups, but no significant association existed between lipid-testing interval and hemorrhagic stroke risk. (4) Conclusions: Lipid-testing intervals of more than 6 months may lead to increased stroke risk among newly diagnosed dyslipidemia patients after initiation of statin treatment. Lipid testing every 6 months can lower stroke risk among dyslipidemia patients.

The impact of different prostate-specific antigen (PSA) testing intervals on Gleason score at diagnosis and the risk of experiencing false-positive biopsy recommendations: a population-based cohort study

ObjectiveGiven a man’s current prostate- specific antigen (PSA) level, age and family history of prostate cancer, what are the benefits (decreased risk of higher Gleason score [GS] cancer at diagnosis) and harms (increased risk of false-positive biopsy recommendation) of waiting 1, 2, 3, 4 or 5–8 years until the next PSA test?DesignProspective cohort.SettingAll PSA tested men in Stockholm, Sweden, between 2003 and 2015.ParticipantsMen aged 50–74 years with at least two PSA tests between 2003 and 2015 (n=174 636).Main outcome measuresLog-binomial regression to calculate the risk ratio (RR) of GS ≥7 and GS 6 versus benign outcome at prostate biopsy and 12-year cumulative probability of experiencing a false-positive biopsy by testing interval, age, PSA level and first-degree family history.ResultsMen with PSA ≤1 ng/mL had low risk of GS ≥7 prostate cancer irrespective of testing interval; <3% had a PSA >3 at the next testing occasion, and of the 663 men biopsied after the next PSA test only 32 (5%) had GS ≥7 cancer. Men with PSA >1 ng/mL had increased risk of being diagnosed with GS ≥7 prostate cancer when screened with longer than annual intervals (RRs ranged from 1.4 to 3.2 depending on PSA level and testing interval). The results were consistent across age groups and family history status. This benefit needs to be balanced against the increased risk for false-positive biopsy recommendation with shorter testing intervals (twofold for annual vs biennial and threefold for annual vs triennial).ConclusionsMen aged 50–74 years with PSA ≤1 ng/mL can wait 3–4 years before having a new PSA test. For men with PSA >1 ng/mL, we observed an increased risk of being diagnosed with GS ≥7 prostate cancer with longer than annual testing intervals. This benefit needs to be balanced against the markedly increased risks for false-positive biopsy recommendations with shorter testing intervals recommendations.

Monitoring Thyroid Function in Patients on Levothyroxine. Assessment of Conformity to National Guidance and Variability in Practice

With demand for endocrine tests steadily increasing year-on-year, we examined thyroid function test (TFT) frequencies in patients on levothyroxine replacement therapy to assess the effect of initial TFT results and request source on TFT re-testing interval. All TFTs performed by the Clinical Biochemistry Departments at the Salford Royal Hospital (2009–2012; 288 263 requests from 139 793 patients) and University Hospital of North Midlands (2011–2014; 579 156 requests from 193 035 patients) were extracted from the laboratory computer systems. Of these, 54 894 tests were on 13 297 patients confirmed to be on levothyroxine therapy in the test cohort (Salford) and 67 298 requests on 11 971 patients in the confirmatory cohort (North Midlands). In the test cohort, median TFT re-testing interval in the total group was 19.1 weeks (IQR 9.1–37.7 weeks), with clearly defined peaks in TFT re-testing evident at 6 and 12 months and a prominent broad peak at 1–3 months. Median re-test interval was much lower than recommended (52 weeks) for those with normal TFTs at 31.3 weeks (30.6 weeks for the confirmatory cohort). Where thyroid-stimulating hormone (TSH) was elevated and free thyroxine (fT4) was below the reference range, re-test interval was much longer than is recommended (8 weeks) at 13.4–17.6 weeks (7.1–23.4 weeks in the confirmatory cohort), as was the interval when TSH was below and fT4 was above the normal range, at 16.7–25.6 weeks (27.5–31.9 weeks in the confirmatory cohort). Our findings show that the majority of TFT requests are requested outside recommended intervals and within-practice variability is high. A new approach to ensuring optimum monitoring frequency is required. Direct requesting from the clinical laboratory may provide one such solution.