Differences in health outcomes associated with initial adherence to oral antidiabetes medications among veterans with uncomplicated Type 2 diabetes: a 5-year survival analysis

AIM

To determine the association of adherence to oral antidiabetes medication with macrovascular and microvascular complications, time to insulin therapy, revascularization, admissions, and death among veterans with uncomplicated diabetes.

METHODS

This was a retrospective cohort study using the Veterans Affairs Corporate Data Warehouse to examine 159 032 veterans diagnosed with uncomplicated diabetes during 2002-2014 and starting oral antidiabetes therapy for the first time. The first uncomplicated diabetes diagnosis was identified and confirmed by subsequent oral antidiabetes therapy initiation. Adherence was calculated from outpatient pharmacy records using the proportion of days covered over the first year of therapy. Health outcomes were observed up to 5 years beyond the first oral antidiabetes agent fill, and compared according to adherence status using Cox proportional hazards models adjusted for baseline demographic and clinical characteristics.

RESULTS

During the first 5 years of oral antidiabetes treatment, people initially non-adherent to oral antidiabetes therapy were more likely to experience myocardial infarction (hazard ratio 1.14, 95% CI 1.03-1.27) and ischaemic stroke (hazard ratio 1.22, 95% CI 1.05-0.1.42), or to die (hazard ratio 1.21; 95% CI 1.15-1.28). Veterans with <20% adherence to oral antidiabetes therapy in the first year had particularly high hazards for ischaemic stroke (hazard ratio 1.78, 95% CI 1.27-2.49) and all-cause death (hazard ratio 1.33, 95% CI 1.17-151). Adherent people were more likely to be diagnosed with a microvascular complication or chronic kidney disease.

CONCLUSIONS

People who are non-adherent to treatment were more likely to experience detrimental health outcomes within the first 5 years of antidiabetes therapy. Adherence is paramount to disease management and this should be stressed from the time at which treatment is initiated.

Solitary fibrous tumor of the ischioanal fossa-a multidisciplinary approach to management with radiologic-pathologic correlation

Solitary fibrous tumors are primary mesenchymal tumors, which may occur in any part of the body. Overall, these tumors are considered to have intermediate malignant potential with 5- and 10-year metastasis-free and overall disease-specific survival rates of 74% and 55%, and 89% and 73%, respectively (Demicco et al, 2012). Herein we present an unusual case of solitary fibrous tumors involving the ischioanal fossa in a 19-year-old woman with radiologic-pathologic correlation. This case was complicated by extensive tumor vascularity and was thus managed with preoperative embolization followed by en bloc surgical resection.

Choice Reaction Times and the Theory of Intermittency in Human Performance

One visual signal, drawn from two equi-probable alternatives, was followed at a variable interval by a similar signal, also drawn from two equi-probable alternatives. The relationship between reaction time to the second signal and the interval between signals was studied under the following conditions: (1) Subjects were trained from the beginning to regard the first signal as irrelevant. (2) Subjects were asked to report on the nature of the first signal after they had responded to the second. The interval between signals was one of the five values, 50, 100, 150, 200, 250 millisec. In the regular interval situation the same interval was used over a block of 20 trials. In the random interval situation the values of the interval were randomly arranged, with equal frequency within each block of 20 trials.

The results showed: (1) In the random interval situation there was a definite disturbing effect of the first signal on the reaction time to the second, despite the fact that subjects were trained to disregard the first signal. However, the delays in reaction time were significant only at the shortest interval, 50 millisec. (2) In the regular interval situation this disturbing effect was not evident. (3) The additional requirement of having to report on the nature of the first signal produced no consistent increase in reaction time to the second signal. Some implications of these results for the conception of the human operator as a channel of limited capacity are discussed.

The Human Operator as a Single Channel Information System

A further experiment is reported on reaction times to stimuli separated by short intervals. On this occasion an auditory stimulus was followed by a visual stimulus. Results indicate that the pattern of delays at short intervals is the same as the pattern of delays when the stimuli are presented in one modality only. This suggests a model of the human operator functioning as a single channel through which information from both sense modalities has to pass before appropriate responses are organized. An attempt is also made to reconcile data with the known facts about the peripheral and central components of reaction time and the possibility that delays are the result of occupation of the channel for a central time plus a central refractory time is suggested.

Imitative Responses and the Rate of Gain of Information

A series of experiments is described on audio-verbal reaction times. In the first experiment the signals were letters or digits recorded on magnetic tape and presented through earphones. In the second experiment the signals were nonsense syllables drawn from vocabularies of different size. The subjects responded by repeating what they heard as soon as it was presented and reaction times were recorded. It is shown that the size of the group from which the signal is drawn has little effect on the reaction time to that signal. A distinction is drawn between situations in which the rate of gain of information may be expected to apply and situations in which it may not apply. It is suggested that many highly practiced skills fall into the latter category.

The Role of “Attention” in the Psychological Refractory Period

A set of experiments is described in which two consecutive signals, separated by a variable time interval, were presented to the subjects. Manual reaction times to these signals were recorded and the delays in the reactions to the second of the two signals were compared in situations where the subject was required to respond to both signals and where he was not required to respond to the first signal.

The magnitude of the delays found at any particular interval were the same in both situations, and there was not much difference between cases where the two signals were in the same sense modality (visual) or in different modalities (visual, followed by auditory). These results confirm the suggestion of the writer in a previous paper that there may be a common analysing and classifying system for auditory and visual information and also illustrate a new point. It is paying attention to a signal rather than performing any overt response to it which gives rise to delays in subsequent responses.

The Combination of Information from Different Sources

In this experiment subjects were presented with visual information from two different sources and were required to combine it in order to make the correct response. The time interval between the two signals was varied in two different ways (a) regularly and (b) randomly. Reaction times were measured from the moment of occurrence of the second signal. By this means the time course of the decision procedure involved in combining the information from the two sources was analysed.

Results indicate that subjects may deal with the situation in two ways (i) by means of a “perceptual” classification in which the individual elements are not analysed separately, or (ii) by means of an “intellectual” classification in which each signal is analysed sequentially. These two methods correspond to the experimental conditions of (a) regular intervals and (b) random intervals.

It is argued that when subjects use the latter strategy the results are consistent with the conception of the human operator as an intermittent analysing system.

The Limits of the “Psychological Refractory Period”

Previous evidence on the psychological refractory period is shown to be inadequate on the crucial issue of whether delays, which cannot be overcome by practice, occur in responding to the second of two signals, when the interval between them is less than 0·5 seconds. For simple key pressing responses it is shown that when the interval between signals is less than the reaction time to the first signal, delays in the reaction time to the second signal occur in a predictable manner. When the interval is greater than the first reaction time, however, no such delays are found. Possible reasons for the discrepancy between these and earlier findings are suggested.

Novel C-Terminal Heat Shock Protein 90 Inhibitors (KU711 and Ku757) Are Effective in Targeting Head and Neck Squamous Cell Carcinoma Cancer Stem cells

Advanced head and neck squamous cell carcinoma (HNSCC) remains a therapeutic challenge due to the development of therapy resistance. Several studies have implicated the development of cancer stem cells as a possible mechanism for therapy resistance in HNSCC. Heat shock protein 90's (Hsp90's) molecular chaperone function is implicated in pathways of resistance in HNSCC. Therefore, in the present study, we investigated the efficacy of novel C-terminal Hsp90 inhibitors (KU711 and KU757) in targeting HNSCC cancer stem cells (CSCs). Treatment of HNSCC human cell lines MDA1986, UMSCC 22B, and UMSCC 22B cisplatin-resistant cells with the KU compounds indicated complete blockage of self-renewal for the resistant and parent cell lines starting from 20 μM KU711 and 1 μM KU757. Dose-dependent decrease in the cancer stem cell markers CD44, ALDH, and CD44/ALDH double-positive cells was observed for all cell lines after treatment with KU711 and KU757. When cells were treated with either drug, migration and invasion were downregulated greater than 90% even at the lowest concentrations of 20 μM KU711 and 1 μM KU757. Western blot showed >90% reduction in client protein "stemness" marker BMI-1 and mesenchymal marker vimentin, as well as increase in epithelial marker E-cadherin for both cell lines, indicating epithelial to mesenchymal transition quiescence. Several CSC-mediated miRNAs that play a critical role in HNSCC therapy resistance were also downregulated with KU treatment. In vivo, KU compounds were effective in decreasing tumor growth with no observed toxicity. Taken together, these results indicate that KU compounds are effective therapeutics for targeting HNSCC CSCs.