Racial disparities in low-value surgical care and time to surgery in high-volume hospitals

BACKGROUND

The objective of this study is to examine racial differences in receipt of low-value surgical care and time to surgery (TTS) among women receiving treatment at high-volume hospitals.

METHODS

Stage I-III non-Hispanic Black (NHB) and Non-Hispanic White (NHW) breast cancer patients were identified in the National Cancer Database. Low-value care included (1) sentinel lymph node biopsy (SLNB) among T1N0 patients age ≥70 with hormone receptor-positive cancers, (2) axillary lymph node dissection (ALND) in patients meeting ACOSOG Z0011 criteria, and (3) contralateral prophylactic mastectomy (CPM) with unilateral cancer. TTS was days from biopsy to surgery. Bivariate and logistic regression analyses were used to compare the groups.

RESULTS

Compared to NHWs, NHBs had lower rates of SLNB among women age ≥70 with small hormone-positive cancers (NHB 58.5% vs. NHW 62.2% p < .001) and CPM (NHB 26.3% vs. NHW 36%; p < .001). ALND rates for patients meeting ACOSOG Z0011 criteria were similar between both groups (p = .13). The odds of surgery >60 days were higher among NHBs (odds ratio, 1.77; 95% confidence interval, 1.64-1.91; NHW ref).

CONCLUSIONS

NHBs treated at high-volume hospitals have higher rates of surgical delay but are less likely to undergo low-value surgical procedures compared to NHW women.

Adaptive effects of spaceflight as revealed by short-term partial weight suspension

BACKGROUND

Human performance and adaptation to altered loading levels is investigated. A previous astronaut jumping study demonstrated significantly altered landing performance following spaceflight, complementing reports of postflight postural and gait instabilities. A dynamic model indicated that leg stiffness changes accounted for the kinematic differences due to adaptation in open-loop modulation of leg impedance. Muscular atrophy or altered stretch reflexes and vestibular sensing could not be discounted.

HYPOTHESIS

We hypothesize that partial weight unloading can cause modulation of leg impedance and altered jump landing performance similar to longer-term microgravity exposure, while controlling for muscle atrophy and altered graviceptor inputs. Lower-body impedance changes after partial weight unloading support the hypothesis that postflight differences result primarily from modulation of leg impedance due to reduced postural control demands in microgravity.

METHODS

Six subjects performed six baseline 30-cm downward jumps from a platform, followed by 10 jumps under 60% body weight unloading (the adaptation sequence), and then six additional jumps under full-body loading (termed "adapted jumps"). Joint and mass center kinematics were compared for the baseline and adapted jump landings. A second order model evaluated changes in vertical leg impedance.

RESULTS

Three subjects exhibited significant increased joint angles and rates. Vertical ground reaction forces showed more heavily damped responses after adaptation. Model fits to mass center motion indicated reduced leg stiffness.

CONCLUSIONS

Post-adaptation performance is similar to that of four astronaut subjects who demonstrated reduced postflight leg stiffness. The new study strongly suggests adaptive control of lower limb impedance to accommodate altered gravity levels which can be induced by minimal unloading exposure. Partial weight unloading provides a simple, inexpensive analog to spaceflight for certain postural and movement studies.

Efficacy of conventional endoscopic disinfection and sterilization methods against Helicobacter pylori contamination

BACKGROUND

Iatrogenic transmission of Helicobacter pylori via contaminated endoscopic devices is well documented. Despite the prevalence of this infectious agent, few controlled studies have investigated the major factors that impact on reprocessing of endoscopes contaminated with H. pylori.

MATERIALS AND METHODS

An endoscope (Pentax) was contaminated with 108 cfu/ml of H. pylori in 5% bovine calf serum as standardized inoculum. The endoscope then was passed through one of eight arms (five repetitions per arm = 40 total runs), as follows: 1, recovery control (no cleaning or disinfection); 2, manual cleaning alone; 3-5, manual precleaning followed by either 10-, 20-, or 45-minute exposure to 2% glutaraldehyde and ethanol (ETOH) drying; 6, manual cleaning followed by automated reprocessing by STERIS System; 7 and 8, automated reprocessing by STERIS with and without active peracetic acid sterilant (wash-off control). Suction-biopsy channels and air-water channels were harvested for microbiological culture.

RESULTS

Control runs recovered more than 1 x 106 cfu per site, confirming the viability of the test organism and the adequacy of the biological burden for challenge. When instruments underwent manual cleaning alone (without subsequent disinfection), test organisms remained in 40% of runs at the air-water site. Manual cleaning followed by 10-, 20-, or 45-minute glutaraldehyde exposure and ETOH drying removed all test organisms from all sites in all runs (i.e., 100% disinfection). The automated STERIS system with or without active peracetic acid sterilant also removed all test organisms from all sites in all runs, as did manual cleaning followed by STERIS use.

CONCLUSION

Manual cleaning alone does not effectively remove H. pylori from an endoscope. Current joint association recommendations for minimal disinfection (manual cleaning followed by at least 20 minutes of immersion in glutaraldehyde and ETOH drying) are effective in preventing cross-transmission of H. pylori. Reprocessing using the automated STERIS system according to manufacturer's recommendations also is highly effective in sterilizing endoscopes contaminated with H. pylori.

Antimicrobial efficacy of endoscopic disinfection procedures: a controlled, multifactorial investigation

BACKGROUND

Adequate disinfection of endoscopes is essential to prevent environmental and patient-to-patient transmission of infectious agents, but data from controlled studies are limited. Moreover, there is controversy regarding current guidelines for disinfection. We compared the antimicrobial efficacy of several endoscopic disinfection procedures controlling for multiple factors that affect reprocessing.

METHODS

A colonoscope was contaminated with 10(8) CFU/mL of Enterococcus faecalis as a standardized inoculum. The colonoscope was passed through 1 of 16 study arms (5 reps/arm for a total of 80 runs) that were controlled for all possible combinations of the following variables: manual precleaning; 10-, 20-, or 45-minute glutaraldehyde exposure; air or ethanol drying; or automated reprocessing with peracetic acid (liquid sterilization system). Suction accessory channels and air-water channels were harvested for microbiologic culture.

RESULTS

Control runs (no cleaning or disinfection) recovered more than 5 x 10(7) CFU/mL from each sampling site. When each processing variable was isolated independent of other variables, the benefits of manual precleaning, longer soak times, and ethanol drying were apparent. When factors were combined, manual precleaning followed by 20- and 45-minute glutaraldehyde exposure and ethanol drying removed all test organisms, as did processing with the liquid sterilization system.

CONCLUSION

Although the initial cost is higher, the automated liquid sterilization system provides effective sterilization and minimizes worker exposure. In units where chemical disinfection is used, our results suggest that manual precleaning followed by at least 20-minute glutaraldehyde exposure and ethanol rinse drying are sufficient to achieve complete disinfection.

Altered astronaut lower limb and mass center kinematics in downward jumping following space flight

Astronauts exposed to the microgravity conditions encountered during space flight exhibit postural and gait instabilities upon return to earth that could impair critical postflight performance. The aim of the present study was to determine the effects of microgravity exposure on astronauts' performance of two-footed jump landings. Nine astronauts from several Space Shuttle missions were tested both preflight and postflight with a series of voluntary, two-footed downward hops from a 30-cm-high step. A video-based, three-dimensional motion-analysis system permitted calculation of body segment positions and joint angular displacements. Phase-plane plots of knee, hip, and ankle angular velocities compared with the corresponding joint angles were used to describe the lower limb kinematics during jump landings. The position of the whole-body center of mass (COM) was also estimated in the sagittal plane using an eight-segment body model. Four of nine subjects exhibited expanded phase-plane portraits postflight, with significant increases in peak joint flexion angles and flexion rates following space flight. In contrast, two subjects showed significant contractions of their phase-plane portraits postflight and three subjects showed insignificant overall changes after space flight. Analysis of the vertical COM motion generally supported the joint angle results. Subjects with expanded joint angle phase-plane portraits postflight exhibited larger downward deviations of the COM and longer times from impact to peak deflection, as well as lower upward recovery velocities. Subjects with postflight joint angle phase-plane contraction demonstrated opposite effects in the COM motion. The joint kinematics results indicated the existence of two contrasting response modes due to microgravity exposure. Most subjects exhibited "compliant" impact absorption postflight, consistent with decreased limb stiffness and damping, and a reduction in the bandwidth of the postural control system. Fewer subjects showed "stiff" behavior after space flight, where contractions in the phase-plane portraits pointed to an increase in control bandwidth. The changes appeared to result from adaptive modifications in the control of lower limb impedance. A simple 2nd-order model of the vertical COM motion indicated that changes in the effective vertical stiffness of the legs can predict key features of the postflight performance. Compliant responses may reflect inflight adaptation due to altered demands on the postural control system in microgravity, while stiff behavior may result from overcompensation postflight for the presumed reduction in limb stiffness inflight.

Enhancing the effectiveness of abortive therapy: a controlled evaluation of self-management training

Research suggests that approximately one half of recurrent headache sufferers fail to adhere properly to drug treatment regimens with as many as two thirds of patients failing to make optimal use of abortive medications such as ergotamine. In spite of these findings there are no controlled studies that have attempted to evaluate methods for improving adherence to drug regimens for the treatment of chronic headache disorders. In an initial effort to address this adherence problem thirty-four recurrent migraine sufferers were randomized to abortive therapy with ergotamine tartrate plus caffeine (standard abortive therapy) or to standard abortive therapy accompanied by a brief educational intervention designed to facilitate the migraine sufferer's effective use of ergotamine. Patients who received the adjunctive educational intervention attempted to abort a greater percentage of their migraine attacks (70% vs 40%) and showed larger reduction in headache activity (e.g., 40% vs 26% reduction in month two of treatment). However, patients in both treatment groups used similar amounts of abortive medication when attempting to abort a migraine attack and showed similar reductions in analgesic medication use with abortive therapy. There results suggest that brief educational interventions designed to address the problem of patient adherence may yield significant improvements in standard therapies. We argue that such educational interventions deserve more attention in the headache treatment literature than they have received to date.

Relation between mycoplasmas and leukaemia and related diseases

Forty-five bone marrow specimens from leukaemia patients and 40 marrows from nonleukaemia patients were cultured for mycoplasmas. No mycoplasmas were isolated. Sera from patients with leukaemia or reticuloses and from non-leukaemic subjects were examined for antibodies to the Negroni and 880 strains of Mycoplasma pulmonis and also to the K7, K10, and prototype (PG18) strains of M. fermentans. No significant differences were observed between the two groups of patients with respect to antibodies to these mycoplasmas. These findings support those of the majority of other workers in failing to show any relationship between mycoplasmas and neoplastic disease in man.