Assessment of treatment outcome in current de-escalation for differentiated thyroid cancer (DTC) according to the 2015 Dutch thyroid cancer guidelines (NL-15) and American Thyroid Association guidelines (ATA-15).
Retrospectively, the recommendations of the NL-15 and ATA-15 guidelines were evaluated to estimate potentially adequate, under- and overtreatment of DTC in patients treated in the University Medical Center Groningen between 2007 and 2017.
A total of 240 patients with a cT1-T3aN0-1aM0 DTC fulfilled the inclusion criteria.
After actual treatment was given, patients were again categorized according to both guidelines into low, intermediate, or high-risk based on tumour status. Next, they were categorized into a congruent low-risk (n = 60), congruent high-risk (n = 73), or incongruent risk group (n = 107). Follow-up data were used to estimate the proportion of potentially adequate, under-, and overtreatment according to both guidelines.
Comparing treatment recommended by NL-15 and ATA-15 showed significantly more over- and adequate treatment when following NL-15 recommendations, and more undertreatment following ATA-15 (all: p < .001). Subanalysis of the congruent low-risk group showed overtreatment in 64% when following NL-15 guidelines (p < .001). No treatment differences were found in the congruent high-risk group. Undertreatment was most often seen in the incongruent risk group when following ATA-15 (p < .001).
Low-risk patients were treated too aggressively when following NL-15 recommendations, where the less aggressive ATA-15 approach seemed more adequate. Treatment of intermediate risk DTC patients varies greatly, with a relative higher rate of undertreatment according to the recommendations of the ATA-15, advocating further refining of the risk classification in this patient group.

Guidelines for the severity classification and treatment of Clostridium difficile infection (CDI) were published by Infectious Diseases Society of America (IDSA)/Society for Healthcare Epidemiology of America (SHEA) in 2010; however, compliance and efficacy of these guidelines has not been widely investigated. This present study assessed compliance with guidelines and its effect on CDI patient outcomes as compared with before these recommendations. A retrospective study included all adult inpatients with an initial episode of CDI treated in a single academic center from January 2009 to August 2014. Patients after guideline publication were compared with patients treated in 2009-2010. Demographic, clinical, and laboratory data were collected to stratify for disease severity. Outcome measures included compliance with guidelines, mortality, length of stay (LOS), and surgical intervention for CDI. A total of 1021 patients with CDI were included. Based upon the 2010 guidelines, 42 (28·8%) of 146 patients treated in 2009 would have been considered undertreated, and treatment progressively improved over time, as inadequate treatment decreased to 10·0% (15/148 patients) in 2014 (P = 0·0005). Overall, patient outcomes with guideline-adherent treatment decreased CDI attributable mortality twofold (P = 0·006) and CDI-related LOS by 1·9 days (P = 0·0009) when compared with undertreated patients. Compliance with IDSA/SHEA guidelines was associated with a decreased risk of mortality and LOS in hospitalized patients with CDI.

Over recent years, adjuvant systemic treatment guidelines (AST) for early-stage breast cancer have changed considerably. We aimed to assess the impact of these guideline changes on the administration of AST in early-stage breast cancer patients and to what extent these guidelines are adhered to at a nation-wide level. We used Netherlands Cancer Registry data to describe trends in AST prescription, adherence to AST guidelines, and to identify clinicopathological determinants of nonadherence. Between 1990 and 2012, 231,648 Dutch patients were diagnosed with early breast cancer, of whom 124,472 received AST. Adjuvant endocrine treatment (ET) use increased from 23 % of patients (1990) to 56 % (2012), and chemotherapy from 11 to 44 %. In 2009-2012, 8 % of patients received ET and 3 % received chemotherapy without guideline indication. Conversely, 10-29 % of patients did not receive ET and chemotherapy, respectively, despite a guideline indication. Unfavorable clinicopathological characteristics generally decreased the chance of undertreatment and increased the chance for overtreatment. Remarkable was the increased chance of ET undertreatment in younger women (RR < 35 vs 60-69 years 1.79; 95 % CI 1.30-2.47) and in women with HER2+ disease (RR 1.64; 95 % CI 1.46-1.85). Over the years, AST guidelines expanded resulting in much more Dutch early breast cancer patients receiving AST. In the majority of cases, AST administration was guideline concordant, but the high frequency of chemotherapy undertreatment in some subgroups suggests limited AST guideline support in these patients.