Is Myocardial Infarction Overdiagnosed?

This Viewpoint examines whether overdiagnosis rather than underdiagnosis may now be the dominant form of myocardial infarction misdiagnosis.

Ecological study estimating melanoma overdiagnosis in the USA using the lifetime risk method.

OBJECTIVES: To quantify the proportion of melanoma diagnoses (invasive and in situ) in the USA that might be overdiagnosed. DESIGN: In this ecological study, incidence and mortality data were collected from the Surveillance, Epidemiology and End Results 9 registries database. DevCan software was used to calculate the cumulative lifetime risk of being diagnosed with melanoma between 1975 and 2018, with adjustments made for changes in longevity and risk factors over the study period. SETTING: USA. PARTICIPANTS: White American men and women (1975-2018). MAIN OUTCOME MEASURES: The primary outcome was excess lifetime risk of melanoma diagnosis between 1976 and 2018 (adjusted for year 2018 competing mortality and changes in risk factors), which was inferred as likely overdiagnosis. The secondary outcome was an excess lifetime risk of melanoma diagnosis in each year between 1976 and 2018 (adjusted and unadjusted). RESULTS: Between 1975 and 2018 the adjusted lifetime risk of being diagnosed with melanoma (invasive and in situ) increased from 3.2% (1 in 31) to 6.4% (1 in 16) among white men, and from 1.6% (1 in 63) to 4.5% (1 in 22) among white women. Over the same period, the adjusted lifetime risk of being diagnosed with melanoma in situ increased from 0.17% (1 in 588) to 2.7% (1 in 37) in white men and 0.08% (1 in 1250) to 2.0% (1 in 50) in white women. An estimated 49.7% of melanomas diagnosed in white men and 64.6% in white women were overdiagnosed in 2018. Among people diagnosed with melanomas in situ, 89.4% of white men and 85.4% of white women were likely overdiagnosed in 2018. CONCLUSIONS: Melanoma overdiagnosis among white Americans is significant and increasing over time with an estimated 44 000 overdiagnosed in men and 39 000 in women in 2018. A large proportion of overdiagnosed melanomas are in situ cancers, pointing to a potential focus for intervention.

Discriminative capacity of guideline recommendations in the assessment of patients with asymptomatic microhematuria.

BACKGROUND & OBJECTIVE: Asymptomatic microhematuria (aMh) remains a diagnostic challenge in urological practice: while aMh is a risk factor of urothelial carcinoma (UC), prevalence of aMh is high. Guidelines were developed to permit risk stratification and reduce diagnostic workload. This study investigates the efficacy of several recommendations. MATERIAL & METHODS: Sixty hundred eight patients with newly diagnosed aMh without previous UC from an academic referral center (A; n = 320) and a private outpatient clinic (B; n = 288) were included. All patients underwent clinical workup including medical history, urine cytology, upper tract imaging and cystoscopy. Eleven former and current guidelines were applied to each patient individually; every patient was classified as either low risk (no further workup recommended) or high risk. Furthermore, a recently developed nomogram for hematuria assessment was included. RESULTS: The cohort comprised 142 females and 466 males (mean age 62 [range 18-92] years). Sixty-one patients (10.0%) were diagnosed with UC. Excluding the Swedish and recent NICE guideline generally advising against urologic workup, application of 9 other recommendations would have diagnosed all UCs and saved 1.6% to 16.1% of patients from workup. For the 2020 US guideline, solely applied to cohort B, 10.6% of patients were classified as low risk. The use of the nomogram would have saved 17.1% to 25% of patients from workup. CONCLUSIONS: Practical relevance of current guidelines is limited as they do not sufficiently identify patients not requiring clinical work up. Thus, guideline adherence may trigger overdiagnosis and even overtreatment. New ways of risk stratification are needed to improve aMh assessment.

QT prolongation is over-estimated by Bazett compared to Friderica in Japanese child and adolescent inpatients.

Recent researches suggested that the risk of drug-induced QTc prolongation is low in child and adolescent psychiatry setting. However, these cohorts enrolled mainly of Caucasian background. We aimed to assess the prevalence of QTc prolongation and its association with antipsychotic use in Japanese youth. The medical records of inpatients were reviewed. Two different definitions of QT prolongation, Bazett's corrected QT interval (QTcB) >450 msec and Fridericia's corrected QT interval (QTcF) >450 msec, were adopted. In 220 participants [age: 13.4 ± 2.3 years, antipsychotics according to the chlorpromazine equivalence: 50 (25th-75th percentiles; 0-150) mg/day], the prevalence of QTcB and QTcF prolongation was 13.6 and 2.3%, respectively. Patients with QTcB >450 msec had a significantly higher heart rate than those with QTcB ≤450 msec (91.2 ± 20.6 bpm vs. 76.1 ± 15.2 bpm; P < 0.001). The other variables, except potassium level (4.1 ± 0.4 mEq/L vs. 4.2 ± 0.3 mEq/L; P = 0.030), showed no significant difference. Clinically meaningful QTc prolongation was rare even in this Japanese cohort. This study also suggested that if QTcB is used, clinicians should be aware of possible overdiagnosis of QTc prolongation due to accelerated heart rate.

Overdiagnosis of Malaria Illness in an Endemic Setting: A Facility-Based Surveillance Study in Malawi.

In endemic settings where asymptomatic malaria infections are common, malaria infection can complicate fever diagnosis. Factors influencing fever misdiagnosis, including accuracy of malaria rapid diagnostic tests (mRDTs) and the malaria-attributable fraction of fevers (MAF), require further investigation. We conducted facility-based surveillance in Malawi, from January 2012 through December 2013 in settings of high perennial (Chikhwawa), high seasonal (Thoylo), and moderate seasonal (Ndirande) malaria transmission. Consecutive patients presenting to outpatient departments were screened; those with suspected malaria illness were tested by mRDT or routine thick-smear microscopy. Test positivity rates (TPRs), positive predictive value (PPVs) of mRDTs, and MAFs were calculated by site, age, and season. Of 41,471 patients, 10,052 (24.2%) tested positive for malaria. The TPR was significantly greater in Chikhwawa (29.9%; 95% CI, 28.6-30.0) compared with Thyolo (13.2%; 95% CI, 12.5-13.7) and Ndirande (13.1%; 95% CI, 12.2-14.4). The overall PPV was 77.8% (95% CI, 76.8-78.7); it was lowest among infants (69.9%; 95% CI, 65.5-74.2) and highest among school-age children (81.9%; 95% CI, 80.3-83.4). Malaria infection accounted for about 50% of fevers in children younger than 5 years old with microscopy-confirmed Plasmodium falciparum infection, and less than 20% of such fevers in school-age children. Outpatient settings in Malawi had a high burden of malaria illness, but also possible overdiagnosis of malaria illness. Interventions to reduce malaria transmission and rapid testing for other common febrile illness may improve diagnostic clarity among outpatients in malaria endemic settings.