Pain, Analgesic Use, and Patient Satisfaction With Spinal Versus General Anesthesia for Hip Fracture Surgery : A Randomized Clinical Trial

BACKGROUND

The REGAIN (Regional versus General Anesthesia for Promoting Independence after Hip Fracture) trial found similar ambulation and survival at 60 days with spinal versus general anesthesia for hip fracture surgery. Trial outcomes evaluating pain, prescription analgesic use, and patient satisfaction have not yet been reported.

OBJECTIVE

To compare pain, analgesic use, and satisfaction after hip fracture surgery with spinal versus general anesthesia.

DESIGN

Preplanned secondary analysis of a pragmatic randomized trial. (ClinicalTrials.gov: NCT02507505).

SETTING

46 U.S. and Canadian hospitals.

PARTICIPANTS

Patients aged 50 years or older undergoing hip fracture surgery.

INTERVENTION

Spinal or general anesthesia.

MEASUREMENTS

Pain on postoperative days 1 through 3; 60-, 180-, and 365-day pain and prescription analgesic use; and satisfaction with care.

RESULTS

A total of 1600 patients were enrolled. The average age was 78 years, and 77% were women. A total of 73.5% (1050 of 1428) of patients reported severe pain during the first 24 hours after surgery. Worst pain over the first 24 hours after surgery was greater with spinal anesthesia (rated from 0 [no pain] to 10 [worst pain imaginable]; mean difference, 0.40 [95% CI, 0.12 to 0.68]). Pain did not differ across groups at other time points. Prescription analgesic use at 60 days occurred in 25% (141 of 563) and 18.8% (108 of 574) of patients assigned to spinal and general anesthesia, respectively (relative risk, 1.33 [CI, 1.06 to 1.65]). Satisfaction was similar across groups.

LIMITATION

Missing outcome data and multiple outcomes assessed.

CONCLUSION

Severe pain is common after hip fracture. Spinal anesthesia was associated with more pain in the first 24 hours after surgery and more prescription analgesic use at 60 days compared with general anesthesia.

PRIMARY FUNDING SOURCE

Patient-Centered Outcomes Research Institute.

Clinically Important Differences for Mobility Measures Derived from the Testosterone Trials

BACKGROUND/OBJECTIVES

Accurate estimates of clinically important difference (CID) are required for interpreting the clinical importance of treatments to improve physical function, but CID estimates vary in different disease populations. We determined the CID for two common measures of walking ability in mobility-limited older men.

DESIGN

Longitudinal, multisite placebo-controlled trial.

SETTING/PARTICIPANTS

Men enrolled in the Testosterone Trials who had self-reported mobility limitation and gait speed less than 1.2 m/second (n = 429). Testosterone- and placebo-allocated participants were combined for this study.

RESULTS

Mean changes from baseline, adjusting for time-in-intervention and site, were 29.6, 13.2, 12.5, -2.4, and -32.6 m for 6MWD, and 15.4, 7.2, 2.1, -3.4, and -7.2 for PF10 in men who reported their mobility was "very/much better," "little better," "no change," "little worse," or "much worse," respectively. CID estimates using regression, ROC, and eCDF varied from 5.0-29.6 m for 6MWD, and 5.0-15.2 points for PF10.

CONCLUSION

CID estimates vary by the population studied and by the method and precision of measurement. Increases of 16 to 30 m for 6MWD and 5 to 15 points for PF10 over 12 months appear to be clinically meaningful in mobility-limited, older hypogonadal men. These CID estimates may be useful in the design of efficacy trials of therapies to improve physical function.

Biomarkers and Noncalcified Coronary Artery Plaque Progression in Older Men Treated With Testosterone

OBJECTIVE

Recent results from the Cardiovascular Trial of the Testosterone Trials showed that testosterone treatment of older men with low testosterone was associated with greater progression of noncalcified plaque (NCP). We evaluated the effect of anthropometric measures and cardiovascular biomarkers on plaque progression in individuals in the Testosterone Trial.

METHODS

The Cardiovascular part of the trial included 170 men aged 65 years or older with low testosterone. Participants received testosterone gel or placebo gel for 12 months. The primary outcome was change in NCP volume from baseline to 12 months, as determined by coronary computed tomography angiography (CCTA). We assayed several markers of cardiovascular risk and analyzed each marker individually in a model as predictive variables and change in NCP as the dependent variable.

RESULTS

Of 170 enrollees, 138 (73 testosterone, 65 placebo) completed the study and were available for the primary analysis. Of 10 markers evaluated, none showed a significant association with the change in NCP volume, but a significant interaction between treatment assignment and waist-hip ratio (WHR) (P = 0.0014) indicated that this variable impacted the testosterone effect on NCP volume. The statistical model indicated that for every 0.1 change in the WHR, the testosterone-induced 12-month change in NCP volume increased by 26.96 mm3 (95% confidence interval, 7.72-46.20).

CONCLUSION

Among older men with low testosterone treated for 1 year, greater WHR was associated with greater NCP progression, as measured by CCTA. Other biomarkers and anthropometric measures did not show statistically significant association with plaque progression.

Validity and Clinically Meaningful Changes in the Psychosexual Daily Questionnaire and Derogatis Interview for Sexual Function Assessment: Results From the Testosterone Trials

BACKGROUND

Limited information is available on the performance characteristics of 2 questionnaires commonly used in clinical research, the Psychosexual Daily Questionnaire (PDQ) and the Derogatis Interview for Sexual Function (DISF)-II Assessment, especially in older men with low testosterone (T) and impaired sexual function.

AIM

To determine reliability of PDQ and DISF-II by assessing the correlation within and between domains in the questionnaires and to define clinically meaningful changes in sexual activity (PDQ question 4 [Q4]) and desire (DISF-II sexual desire domain [SDD]) domains.

METHODS

Data from 470 men participating in the T Trials were used to calculate Spearman correlation coefficients of individual items and total score among questionnaires to determine convergent and construct validity. Clinically meaningful changes for sexual desire and activity were determined by randomly dividing the sample into training and validation sets. Anchor- and distribution-based clinically meaningful change criteria were defined in the training set, and selected changes were evaluated in the validation set.

OUTCOMES

Validity of the PDQ and DISF-II and clinically meaningful changes in sexual desire and activity were determined in older men in T Trials.

RESULTS

Moderate to strong correlations were shown within and between domains from different questionnaires. Using Patient Global Impression of Change as an anchor, clinically meaningful change in PDQ sexual activity was ≥0.6, and in DISF-SDD was ≥5.0. Applying these change cut-points to the validation set, a greater proportion of T-treated men achieved clinically meaningful improvement in their sexual desire and activity compared to placebo-treated men.

CLINICAL IMPLICATIONS

The PDQ-Q4 and DISF-II-SDD can be used to reliably assess clinically meaningful changes in sexual activity and sexual desire in hypogonadal men treated with T.

STRENGTHS & LIMITATIONS

Strengths of this study include a large sample size, long trial duration, and inclusion of men with low libido and unequivocally low T levels. Limitations include using data from a single study that enrolled only older hypogonadal men, and only 1 anchor for both sexual desire and activity.

CONCLUSION

Moderate to strong correlations were demonstrated within and between different sexual domains of the PDQ and DISF-II confirming construct and convergent validity. Clinically meaningful improvement in elderly hypogonadal men was change of ≥0.6 score in the PDQ-Q4 and ≥5.0 in the DISF-SDD. Improvements in sexual activity and desire in the T Trials were modest but clinically meaningful. Wang C, Stephens-Shields AJ, DeRogatis LR, et al. Validity and Clinically Meaningful Changes in the Psychosexual Daily Questionnaire and Derogatis Interview for Sexual Function Assessment: Results From the Testosterone Trials. J Sex Med 2018;15:997-1009.

Prostate-Specific Antigen Levels During Testosterone Treatment of Hypogonadal Older Men: Data from a Controlled Trial

CONTEXT

Prostate-specific antigen (PSA) changes during testosterone treatment of older hypogonadal men have not been rigorously evaluated.

DESIGN

Double-blinded, placebo-controlled trial.

SETTING

Twelve US academic medical centers.

PARTICIPANTS

Seven hundred ninety hypogonadal men ≥65 years of age with average testosterone levels ≤275 ng/dL. Men at high risk for prostate cancer were excluded.

INTERVENTIONS

Testosterone or placebo gel for 12 months.

MAIN OUTCOMES

Percentile changes in PSA during testosterone treatment of 12 months.

RESULTS

Testosterone treatment that increased testosterone levels from 232 ± 63 ng/dL to midnormal was associated with a small but substantially greater increase (P < 0.001) in PSA levels than placebo treatment. Serum PSA levels increased from 1.14 ± 0.86 ng/mL (mean ± SD) at baseline by 0.47 ± 1.1 ng/mL at 12 months in the testosterone group and from 1.25 ± 0.86 ng/mL by 0.06 ± 0.72 ng/mL in the placebo group. Five percent of men treated with testosterone had an increase ≥1.7 ng/mL and 2.5% of men had an increase of ≥3.4 ng/mL. A confirmed absolute PSA >4.0 ng/mL at 12 months was observed in 1.9% of men in the testosterone group and 0.3% in the placebo group. Four men were diagnosed with prostate cancer; two were Gleason 8.

CONCLUSIONS

When hypogonadal older men with normal baseline PSA are treated with testosterone, 5% had an increase in PSA ≥1.7 ng/mL, and 2.5% had an increase ≥3.4 ng/mL.

Clinically Meaningful Change in Sexual Desire in the Psychosexual Daily Questionnaire in Older Men from the TTrials

BACKGROUND

A recent study of older men participating in the Testosterone Trials (TTrials) defined a clinically meaningful change in the Psychosexual Daily Questionnaire (PDQ) question 4 in hypogonadal men age ≥65 years. This study defines clinically meaningful change in the same population for sexual desire assessed by PDQ question 1.

AIM

To determine a clinically meaningful change in the answers to question 1 of the PDQ in hypogonadal older men.

METHODS

Participants in the Sexual Function Trial of the TTrials were randomly divided into a training and test set. Anchor-based methods, including regression analysis, receiver operating characteristic curves, and empirical cumulative distribution functions, were used to determine a clinically meaningful change on question 1 in the training set, and the selected threshold was evaluated in the test set for an effect of testosterone treatment.

RESULTS

A clinically meaningful increase in question 1 of the PDQ was determined to be ≥0.7 points.

CLINICAL IMPLICATIONS

Question 1 of the PDQ can be used to assess sexual desire in response to testosterone treatment.

STRENGTHS & LIMITATIONS

Data were obtained from a single large study of older hypogonadal men.

CONCLUSION

Clinically meaningful improvement of sexual desire is a change of ≥0.7 in the score of question 1 of the PDQ. Stephens-Shields AJ, Wang C, Preston P, et al. Clinically Meaningful Change in Sexual Desire in the Psychosexual Daily Questionnaire in Older Men from the TTrials. J Sex Med 2019;16:951-953.

Effect of testosterone replacement on measures of mobility in older men with mobility limitation and low testosterone concentrations: secondary analyses of the Testosterone Trials

BACKGROUND

The Physical Function Trial (PFT) was one of seven Testosterone Trials (TTrials), the aim of which was to assess the effect of testosterone on mobility, self-reported physical function, falls, and patient global impression-of-change (PGIC) in older men with low testosterone concentrations, self-reported mobility limitation, and walking speed of less than 1·2 m/s. Using data from the PFT and the overall TTrials study population, we also aimed to identify whether the effect of testosterone on mobility differed according to baseline walking speed, mobility limitation, or other participant-level factors.

METHODS

The TTrials included 790 men aged 65 years or older and with an average of two total testosterone concentrations below 275 ng/dL (9·5 nmol/L), of whom 390 had mobility limitation and a walking speed below 1·2 m/s and were enrolled in the PFT. Participants were assigned (by minimisation method) to 1% testosterone gel or placebo gel daily for 12 months, with participants and study staff masked to intervention allocation. The primary outcome of the PFT was an increase in 6 min walk test (6MWT) distance of 50 m or more. Here we report data for absolute change in 6MWT distance and physical component of Short Form-36 (PF10), and for PGIC and falls. Data are reported for men enrolled in the PFT and those who were not, and for all men in TTrials; data are also reported according to baseline walking speed and mobility limitation. Analyses were done in a modified intention-to-treat population in all patients who were allocated to treatment, had a baseline assessment, and at least one post-intervention assessment. The TTrials are registered with ClinicalTrials.gov, number NCT00799617.

FINDINGS

The TTrials took place between April 28, 2011 and June 16, 2014. Of 790 TTrials participants, 395 were allocated to testosterone and 395 to placebo; of the 390 participants enrolled in the PFT, 193 were allocated to testosterone and 197 to placebo. As reported previously, 6MWT distance improved significantly more in the testosterone than in the placebo group among all men in the TTrials, but not in those who were enrolled in the PFT; among TTrials participants not enrolled in the PFT, 6MWT distance improved with a treatment effect of 8·9 m (95% CI 2·2-15·6; p=0·010). As reported previously, PF10 improved more in the testosterone group than in the placebo group in all men in TTrials and in men enrolled in the PFT; among those not enrolled in the PFT, PF10 improved with an effect size of 4·0 (1·5-6·5; p=0·0019). Testosterone-treated men with baseline walking speed of 1·2 m/s or higher had significantly greater improvements in 6MWT distance (treatment effect 14·2 m, 6·5-21·9; p=0·0004) and PF10 (4·9, 2·2-7·7; p=0·0005) than placebo-treated men. Testosterone-treated men reporting mobility limitation showed significantly more improvement in 6MWT distance (7·6 m, 1·0-14·1; p=0·0237) and PF10 (3·6, 1·3-5·9; p=0·0018) than placebo-treated men. Men in the testosterone group were more likely to perceive improvement in their walking ability (PGIC) than men in the placebo group, both for men enrolled in the PFT (effect size 2·21, 1·35-3·63; p=0·0018) and those not enrolled in the PFT (3·01, 1·61-5·63; p=0·0006). Changes in 6MWT distance were significantly associated with changes in testosterone, free testosterone, dihydrotestosterone, and haemoglobin concentrations. Fall frequency during the intervention period was identical in the two treatment groups of the TTrials (103 [27%] of 380 analysed in both groups had at least one fall).

INTERPRETATION

Testosterone therapy consistently improved self-reported walking ability, modestly improved 6MWT distance (across all TTtrials participants), but did not affect falls. The effect of testosterone on mobility measures were related to baseline gait speed and self-reported mobility limitation, and changes in testosterone and haemoglobin concentrations.

FUNDING

US National Institute on Aging and AbbVie.

Antithrombotic properties of rafigrelide: a phase 1, open-label, non-randomised, single-sequence, crossover study

Platelets play a central role in atherothrombotic events. We investigated the effect of a novel platelet-lowering agent, rafigrelide, on thrombus formation and characteristics. In this phase 1, open-label, non-randomised, single-sequence, crossover study, healthy male volunteers received rafigrelide for 14 days (Period 1). Following a ≥6-week washout period, they then received rafigrelide + acetylsalicylic acid (ASA) for 14 days (Period 2). Thrombus formation was assessed ex vivo using the Badimon perfusion chamber, and thrombus characteristics were assessed using thromboelastography. A total of 15 volunteers were enrolled in the study and were assigned to Panel A or Panel B, which had different schedules of assessments. In Panel A, after treatment with rafigrelide alone (Period 1), mean (± standard deviation) platelet count was reduced from 283 (± 17) × 109/l at Day 1, to 125 (± 47) × 109/l at Day 14 (n=6) and thrombus area reduced under high and low shear conditions. Reductions in thrombus area under high shear conditions correlated with reductions in platelet count (r2=0.11, p=0.022; n=12). Rafigrelide treatment prolonged clot formation time and reduced clot strength. The addition of ASA to rafigrelide (Period 2) had no additional effect on platelet count or thrombus area under high or low shear conditions. Similar results were seen in Panel B for all parameters. The most common adverse events (≥3 participants per period) were thrombocytopenia and headache. While confirming the platelet-lowering effects of rafigrelide, this early phase study also indicates that rafigrelide has antithrombotic properties under both high and low shear conditions.

Effects of Altering Trunk Position during Landings on Patellar Tendon Force and Pain

PURPOSE

This study aimed to verify the immediate effects of altering sagittal plane trunk position during jump landings on lower limb biomechanics, patellar tendon force, and pain of athletes with and without patellar tendinopathy.

METHODS

Twenty-one elite male athletes were categorized into three groups: athletes with patellar tendinopathy (TG; n = 7), asymptomatic athletes with patellar tendon abnormalities (n = 7), and asymptomatic athletes without tendon abnormalities (CG; n = 7). A biomechanical evaluation was conducted while the athletes performed drop landings from a bench in a self-selected trunk position (SS). Afterward, the athletes were randomly assigned to land with either a flexed trunk position (FLX) or an extended trunk position (EXT). Variables of interest for this study included sagittal plane peak kinematics, kinetics, patellar tendon force, and pain during the landing tasks.

RESULTS

Peak patellar tendon force, knee extensor moment, and knee pain decreased in the FLX landing compared with the SS landing, regardless of group. In addition, peak patellar tendon force, knee extensor moment, and vertical ground reaction force were smaller in the FLX landing compared with the EXT landing. The TG had smaller peak ankle dorsiflexion compared with the CG during jump landings, regardless of trunk position.

CONCLUSIONS

Landing with greater trunk flexion decreased patellar tendon force in elite jumping athletes. An immediate decrease in knee pain was also observed in symptomatic athletes with a more flexed trunk position during landing. Increasing trunk flexion during landing might be an important strategy to reduce tendon overload in jumping athletes.

Cost-minimization analysis of lanthanum carbonate versus sevelamer hydrochloride in US patients with end-stage renal disease

PURPOSE

Sevelamer hydrochloride (SH) and lanthanum carbonate (LC) are calcium-free phosphate binders used in the clinical management of hyperphosphatemia in patients with end-stage renal disease (ESRD). The objective of this analysis was to assess the cost-effectiveness of LC monotherapy compared with SH monotherapy in US patients with ESRD in a clinical practice setting.

METHODS

This was a post hoc assessment of phosphate binder costs among US patients with ESRD who converted from SH to LC monotherapy in a previously published, 16-week, Phase IV, real-world study. Calculations of drug costs used both average wholesale price (AWP) and wholesale acquisition cost (WAC).

FINDINGS

There were 953 patients with available baseline SH dose data; 950 also had a recorded LC dose >0 mg at baseline, and 691 had dose data available for both SH at baseline and LC at week 16 (post hoc analysis population). Baseline demographic characteristics were similar in excluded patients and the post hoc analysis population. Mean (SD) serum phosphate levels were 5.91 (1.66) mg/dL at baseline and 5.93 (1.85) mg/dL after conversion to LC monotherapy for 16 weeks. Mean AWP costs were US$35.72 (16.89) per day at baseline and US$24.69 (8.28) per day at week 16, yielding an overall mean cost change (defined as LC cost - SH cost) of -US$11.03 (16.37) per day in favor of LC. The overall mean WAC cost change was -US$9.17 (13.64) per day. Within baseline SH dose subgroups 2400 to 4800, >4800 to 7200, >7200 to 9600, and >9600 mg/d, the mean AWP cost change ranged from US$2.78 (9.26) per day in favor of SH for the 2400- to 4800-mg/d subgroup to -US$33.15 (12.58) per day in favor of LC for the >9600-mg/d subgroup. Mean WAC cost changes showed a similar trend, ranging from US$2.33 (7.72) per day to -US$27.59 (10.48) per day. Linear regression analyses revealed that the inflection SH doses corresponding to a mean cost change of zero were 4905 mg/d (AWP) and 4908 mg/d (WAC). For the 455 (66%) patients in the post hoc analysis population who had baseline SH doses at least as high (≥ 5600 mg/d) as these point estimates, the mean SH:LC tablet ratio was ≥ 3.7, indicating a mean reduction in the tablet burden after conversion to LC of ≥ 73%.

IMPLICATIONS

This real-world assessment of comparative phosphate binder drug costs between SH and LC among US patients with ESRD indicates that average cost savings with LC use increased with increasing SH doses. Conversion to LC from SH ≥ 5600 mg/d reduced drug costs and tablet burden while maintaining serum phosphate levels.

Effect of MMX® mesalamine coadministration on the pharmacokinetics of amoxicillin, ciprofloxacin XR, metronidazole, and sulfamethoxazole: results from four randomized clinical trials

Background

MMX^® mesalamine is a once daily oral 5-aminosalicylic acid formulation, effective in induction and maintenance of ulcerative colitis remission. Patients on long-term mesalamine maintenance may occasionally require concomitant antibiotic treatment for unrelated infections.

Aim

To evaluate the potential for pharmacokinetic interactions between MMX mesalamine and amoxicillin, ciprofloxacin extended release (XR), metronidazole, or sulfamethoxazole in four open-label, randomized, placebo-controlled, two-period crossover studies.

Methods

In all four studies, healthy adults received placebo once daily or MMX mesalamine 4.8 g once daily on days 1–4 in one of two treatment sequences. In studies 1 and 2, subjects also received a single dose of amoxicillin 500 mg (N=62) or ciprofloxacin XR 500 mg (N=30) on day 4. In studies 3 and 4, subjects received metronidazole 750 mg twice daily on days 1–3 and once on day 4 (N=30); or sulfamethoxazole 800 mg/trimethoprim 160 mg twice daily on days 1–3 and once on day 4 (N=44).

Results

MMX mesalamine had no significant effects on systemic exposure to amoxicillin, ciprofloxacin, or metronidazole; the 90% confidence intervals (CIs) around the geometric mean ratios (antibiotic + MMX mesalamine: antibiotic + placebo) for maximum plasma concentration (C_max) and area under the plasma concentration–time curve (AUC) fell within the predefined equivalence range (0.80–1.25). Sulfamethoxazole exposure increased by a statistically significant amount when coadministered with MMX mesalamine; however, increased exposure (by 12% in C_max at steady state; by 15% in AUC at steady state) was not considered clinically significant, as the 90% CIs for each point estimate fell entirely within the predefined equivalence range. Adverse events in all studies were generally mild.

Conclusion

MMX mesalamine may be coadministered with amoxicillin, ciprofloxacin, metronidazole, or sulfamethoxazole, without affecting pharmacokinetics or safety of these antibiotics.

ClinicalTrials.gov identifiers

NCT01442688, NCT01402947, NCT01418365, and NCT01469637.

Changes in fibroblast growth factor 23 levels in normophosphatemic patients with chronic kidney disease stage 3 treated with lanthanum carbonate: results of the PREFECT study, a phase 2a, double blind, randomized, placebo-controlled trial

BACKGROUND

High levels of circulating fibroblast growth factor 23 (FGF23) are associated with chronic kidney disease (CKD) progression and high mortality. In the Phosphate Reduction Evaluation of FGF23 in Early CKD Treatment (PREFECT) study, we assessed the effect of reducing intestinal phosphate absorption using lanthanum carbonate on FGF23 levels in normophosphatemic patients with CKD stage 3.

METHODS

Thirty-five individuals were randomized to lanthanum carbonate 3000 mg/day (n=23) or placebo (n=12) for 12 weeks. Levels of intact FGF23 (iFGF23), C-terminal FGF23, serum and urinary phosphate and calcium, intact parathyroid hormone and 1,25-dihydroxyvitamin D were assessed.

RESULTS

The median age was 65 years in the lanthanum group and 73 years in the placebo group; 58.8% and 41.7% were men, respectively. No significant difference was seen in mean iFGF23 between groups at week 12. There was, however, a transient reduction from baseline in iFGF23 in the lanthanum group at week 1, from 70.5 pg/ml to 51.9 pg/ml, which was not seen in the placebo group; this between-group difference in percentage change from baseline was significant in post hoc analyses (p=0.0102). Urinary phosphate decreased after 1 week of lanthanum treatment and remained low at week 12.

CONCLUSIONS

Reducing intestinal phosphate absorption with lanthanum carbonate did not lead to sustained reductions in iFGF23 in patients with CKD stage 3, although phosphaturia decreased. This suggests that factors other than phosphate burden may be responsible for driving increases in circulating FGF23 in patients with CKD.

TRIAL REGISTRATION

ClinicalTrials.gov NCT01128179, 20 May 2010.

The real-world dose-relativity of sevelamer hydrochloride and lanthanum carbonate monotherapy in patients with end-stage renal disease

INTRODUCTION

Sevelamer hydrochloride (SH) and lanthanum carbonate (LC) are calcium-free phosphate binders used for the management of hyperphosphatemia in patients with end-stage renal disease (ESRD). The objective of this analysis was to evaluate the real-world dose-relativity between SH and LC monotherapy in US patients with ESRD.

METHODS

This was a post hoc analysis of a 16-week, real-world study (Vemuri et al. in BMC Nephrol 12:49, 2011) of the efficacy of conversion to LC monotherapy from other phosphate binders. The SH:LC dose-relativity ratio, based on the mean daily dose, was calculated in the subset of patients from the Vemuri study who converted from SH to LC monotherapy and had available SH and LC dose data.

RESULTS

A total of 950 patients converted from SH to LC monotherapy and had recorded dose data. The post hoc analysis population comprised 691 patients with available dose data for both SH at baseline and LC at week 16. The mean (SD) serum phosphate level at baseline was 5.91 (1.66) mg/dL. After conversion to LC monotherapy for 16 weeks, the mean (SD) serum phosphate level was 5.93 (1.85) mg/dL. The mean (SD) daily baseline SH dose was 7,703 (3,642) mg and the mean (SD) daily LC dose at week 16 was 2,800 (939) mg (9.6 versus 2.8 tablets, respectively; P < 0.0001), resulting in a SH:LC dose-relativity ratio of 2.8. The median individual patient SH:LC dose-relativity ratio was 2.6 (95% CI 2.6-2.8). Across baseline SH dose subgroups (2,400-4,800, >4,800-7,200, >7,200-9,600, and >9,600 mg/day), the mean daily SH dose was 4,051, 7,047, 9,253, and 13,150 mg, respectively. In comparison, the mean daily LC dose was 2,445-3,156 mg. Thus, patients requiring baseline SH doses >7,200 mg/day (41% of the analysis population) had higher SH:LC dose-relativity ratios of 3.1-4.2 (median individual patient ratios 3.1-4.0).

CONCLUSION

In this post hoc analysis of real-world dose-relativity, the overall SH:LC dose-relativity ratio was 2.8 (median individual patient ratio 2.6 (95% CI 2.6-2.8). These findings are consistent with the World Health Organization-defined daily dose and previous studies of the relative phosphate binding capacity of the two drugs. Patients requiring SH doses >7,200 mg/day had higher SH:LC dose-relativities of 3.1-4.2 (median individual patient ratios 3.1-4.0). These findings have implications for the tablet burden and cost-effectiveness of SH and LC in the treatment of hyperphosphatemia.

Current steering for high resolution retinal implants

To significantly increase the resolution achievable by a retinal prosthesis without requiring additional electrodes, a current steering technique could be utilized. In this study, a finite element model was constructed to analyze the local concentrations of charge carrying ions within a saline bath due to concurrent stimulation from two electrodes surrounded by a hexagonal arrangement of return electrodes. By altering the return pathways, tissue activation and identification of unique stimulation patterns is possible. Ag/Ag-Cl electrodes and a voltage controlled current source were developed to validate the finite element model, with the model accurately predicting saline bath measurements. The average error in the returned currents between the finite element model and experimental results was 2% relative to the stimulus current.

In-vitro testing of simultaneous charge injection and recovery in a retinal neuroprosthesis

In order to deliver sufficient phosphene quantities to convey effective vision in a prosthesis device, simultaneous stimuli is necessary. We present in vitro experimental results of the current distribution between stimulation sites during simultaneous stimulation of platinum electrodes immersed in physiological saline. Stimuli were delivered using circuitry that utilizes (a) current source only, (b) current sink only, and (c) the combination of a balanced current source and current sink, to deliver and recover balanced charge at each stimulation site. The results from these experiments support our decision to implement balanced combined current source and current sink circuitry in an application specific integrated circuit (ASIC).

Phyllodes tumour of the prostate posing diagnostic and therapeutic dilemmas

A rare case of phyllodes tumour of the prostate of which less than 100 cases have been reported in the literature. It has an unclear clinical course and uncertain management options. In an inoperable case such as this, the authors discuss the difficulties faced with its management and the limited, possibly palliative role, of hormonal treatment using luteinising hormone-releasing hormone analogue in managing it over a medium term.

Long-term anal continence and quality of life following postpartum anal sphincter injury

OBJECTIVE

Anal incontinence occurs as a result of damage to pelvic floor and the anal sphincter. In women, vaginal delivery has been recognized as the primary cause. To date, figures quoted for overt third degree anal sphincter tear vary between 0% and 26.9% of all vaginal deliveries and the prevalence of anal incontinence following primary repair vary between 15% and 61%. Our aim was to analyse the long-term (minimum 10 years post primary repair) anorectal function and quality of life in a cohort of women who suffered a third degree tear (Group 1) and compare the results with a cohort of women who underwent an uncomplicated vaginal delivery (Group 2) or an elective caesarean delivery (Group 3).

METHOD

In all, 107 patients who suffered a third degree tear between 1981 and 1993 were contacted with a validated questionnaire. The two control groups comprised of 125 patients in each category. Those who responded to the questionnaire were invited for anorectal physiology studies and endoanal ultrasound.

RESULTS

Of the total number contacted, 54, 71 and 54 women from the three groups returned the completed questionnaire. In the three groups, a total of 28 (53%), 13 (19%) and six (11%) complained of anal incontinence (P < 0.0001) respectively. Comparison of quality of life scores between the groups showed a poorer quality of life in those who suffered a tear (P < 0.0001). In addition, in spite of primary repair, 13 (59%) patients in group 1 showed a persistent sphincter defect compared to one (4%) occult defect in Group 2 and none in Group 3.

CONCLUSION

Our study indicates that long-term results of primary repair are not encouraging. It therefore emphasizes the importance of primary prevention and preventing further sphincter damage in those who have already suffered an injury (during subsequent deliveries).

A wideband frequency-shift keying demodulation technique for inductively powered biomedical implants

A digital wideband frequency-shift keying (FSK) demodulator is presented. The primary application of this system is for inductively powered biomedical implants. By providing both the data and the power to the implant via an inductive link, the need for a battery and the interconnect wires are eliminated. This reduces revision surgeries that may take place for maintenance purposes, provides extra safety measures in the case of failures and reduces the risk of infection. However these devices are challenged by power requirements and size availability at the receiving site and often require a high data rate. These challenges lead to the need for an efficient demodulation technique, as traditional methods often do not overcome the restrictions that prevail. The demodulator circuitry presented relies solely on delaying elements, utilising a delayed FSK carrier to sample the incoming FSK waveform. The system architecture is based on a digital environment and both the data and a synchronised clock are derived concurrently. This can be achieved with the coherent-FSK modulated raw binary data stream without the need of any additional baseband coding schemes. The demodulator circuitry was simulated up to a data rate of 5 Mbps while receiving a 5/10 MHz FSK carrier. The system was also implemented on the bench and experimentally tested at a data rate of 1.042 Mbps with no detectable bit error rate while receiving a 4.16/6.25 MHz FSK carrier signal.

An FPGA-Based Vision Prosthesis Prototype: Implementing an Efficient Multiplexing Method for Addressing Electrodes

A prototype of an epi-retinal vision prosthesis based upon an efficient electrode addressing schema has been developed. This system has the ability to stimulate multiple electrode regions simultaneously, hence greatly improving the maximum rate of stimulation compared to many currently available neural stimulation devices based on serial stimulation protocols. To minimize the problem of cross talk between stimulating electrodes, a hexagon layout of electrodes was implemented. Basic tests were completed using a field programmable gate array logic system driving analogue circuitry to inject current into physiological saline via electrodes in hexagon arrangements and in a simple paired arrangement. The hexagon layout of electrodes was shown to clearly reduce the interaction between multiple current sources and hence cross talk.

Bank note recognition for the vision impaired

Blind Australians find great difficulty in recognising bank notes. Each note has the same feel, with no Braille markings, irregular edges or other tangible features. In Australia, there is only one device available that can assist blind people recognise their notes. Internationally, there are devices available; however they are expensive, complex and have not been developed to cater for Australian currency. This paper discusses a new device, the MoneyTalker that takes advantage of the largely different colours and patterns on each Australian bank note and recognises the notes electronically, using the reflection and transmission properties of light. Different coloured lights are transmitted through the inserted note and the corresponding sensors detect distinct ranges of values depending on the colour of the note. Various classification algorithms were studied and the final algorithm was chosen based on accuracy and speed of recognition. The MoneyTalker has shown an accuracy of more than 99%. A blind subject has tested the device and believes that it is usable, compact and affordable. Based on the devices that are available currently in Australia, the MoneyTalker is an effective alternative in terms of accuracy and usability.

Iron-deficiency anaemia caused by an enterolith-filled jejunal duplication cyst

Enterogenous duplication cysts are rare, but recognised, developmental anomalies. Duplications in the midgut are the commonest of these rare anomalies with a high proportion of them being found in the jejunum. Enterolith formation within these duplication cysts is uncommon as is heterotopic mucosa giving rise to peptic ulceration. Mode of presentation depends on whether symptoms due to mass effect or gastrointestinal bleeding predominate. We present a case of iron-deficiency anaemia caused by an enterolith-filled jejunal duplication cyst diagnosed at laparotomy and treated by surgical excision and small bowel resection.

Management strategies for encouraging creativity

Change, chaos, and uncertainty touch every part of every institution. The laboratory is not immune. Managers content to continue on their familiar path soon will find themselves bypassed. To meet today's challenges, directors of technical operations, laboratory directors, team leaders, and coordinators need plenty of creativity--from everyone on their staff. It is no longer just "nice" to improve group output and problem-solving skills while staying within a "shoestring" budget. It is absolutely necessary. In this article, we explore strategies laboratory managers can use to tap the creative potential and commitment of their people. These strategies work. Whether it involves using humor, creating "idea centers," or "deconstructing the bureaucracy," the goal is the same: to encourage clinical managers to think beyond their technical and managerial experience. The examples in this article may not suit the needs, situations, or tastes of all laboratory managers. They are "food for thought." The concepts and strategies these examples illustrate are every laboratory manager's keys to adapting successfully to future challenges.

Chameleon voices: interpreting for deaf parents

As interpreters for their deaf parents, hearing children are a cultural link between two often separate worlds: the Deaf and the Hearing. Data from a 4 year study of adult hearing children throughout the United States indicate significant differences between hearing daughters and hearing sons. Not only were daughters more likely than sons (regardless of birth order or age differences) to interpret for their parents, but daughters were also far more likely to be bilingual: fluent in both spoken English and American Sign Language. A similar gender bias has been observed among the general hearing public: women are far more likely to attend sign language classes and to work as interpreters for the deaf. This paper explores the social mechanisms and cultural values which determine the gender of the way we communicate with one another. Informants' narratives suggest that sign language and the practice of interpreting often touched upon a larger pattern of socialization and status differences between women and men. The discussion then turns to consider how these differences affect the cultural identity of hearing sons versus hearing daughters.

Breaking down barriers to creativity

The author describes six barriers to creativity in the workplace and explains how they can be avoided. He emphasizes the importance of creativity to meet the demands--especially the unforeseen demands--of today's chaotic health-care environment.

Prudent expert systems with credentials: managing the expertise of decision support systems

'Black box' expert systems (ES) are mistrusted by clinicians. Errors generated by medical ES are also a significant cause for concern. We report new ES properties--prudence and credentials--that improve error management and underpin a new approach for improving the credibility of ES for clinical users. Prudent ES modify their output according to past experience. For a knowledge base built from 1610 cases, feature exception prudence (FEP) detected all interpretation errors (100% sensitivity for error detection). Although the false positive rate for FEP was high (47%), the 100% sensitivity meant that the 53% of cases that did not produce flags could be exempted from human validation. As more cases are processed, fewer cases should need human validation. Feature recognition prudence (FRP), a property of ripple down rules (RDR), proposed the correct alternative conclusion in 14% of incorrectly interpreted cases. Human expert validation of the flagged cases enabled context-sensitive credentials (accuracy, incidence and specificity of a given conclusion) to accumulate. Credentials should enable the user to judge the credibility of the ES output. An error management strategy based on credentialed, prudent ES should reduce the impact of error in the clinical environment. The empowerment of clinicians to critically evaluate ES credibility may facilitate greater confidence in, and acceptance of, ES by clinicians.

Mother father deaf: the heritage of difference

Almost 90% of the children born to life-long profoundly deaf parents are hearing. Within this extraordinary family setting, hearing children of deaf parents are exposed to and interact with two differing cultural, social and linguistic systems: that of their deaf parents and the Deaf community, and that of hearing peers and adults. The present paper focuses on cultural identity and affiliation of hearing children of deaf parents--a population whose lives incorporate the paradox of being culturally 'Deaf' and yet functionally hearing. Data reported here are primarily based on interviews and life histories with 150 adult hearing children of deaf parents throughout the United States. The informants in this study provide an opportunity to explore the parameters and norms of Deaf culture as it contrasts and conflicts with those of Hearing culture.

Iron status in women aerobic dance instructors

This investigation evaluated the iron and nutritional status of 12 highly trained aerobic dance instructors who did not take iron supplements (ANS) and 8 who did (AS). A control group (C) consisted of 10 age matched controls. The aerobic instructors had exercised for approximately 3.8 days/wk, 56 min/session for the past 7 yrs. There were no significant differences among groups for energy intake, carbohydrate, protein, fat, nonheme iron, heme iron, or total iron intake (excluding supplemental iron). But both exercise groups had lower ferritin values than the control group. There was also a significant difference in mean cell volume (MCV), with both exercise groups having greater values than the control group. There were no differences among groups for serum iron, total iron binding capacity, transferrin saturation, hematocrit, or hemoglobin. One in three aerobic dance instructors had serum ferritin values below 12 micrograms.L-1. Results indicate that women exercise leaders have iron profiles that are similar to other groups of female athletes. The increased MCV values suggest runners' macrocytosis or an exercise induced macrocytosis.

Report of the results of a double-blind, randomized, single-dose trial of a topical 2% escin gel versus placebo in the acute treatment of experimentally-induced hematoma in volunteers

The efficiency of topically applied 2% escin gel in reducing tenderness to pressure on experimentally induced hematoma is demonstrated. A double-blind, randomized signal dose trial versus placebo in healthy volunteers was used.

Downsizing: the aftermath

Downsizing is perhaps the synonym for management in the 1990's. Many managers believe it is a sure means of lowering overhead, reducing bureaucracy and improving organizational decision making. Downsizing is the systematic reduction in numbers of managers and employees working for an organization. It is designed to make the organization more cost efficient and/or competitive. It is more than simply a matter of cutting some number of employees from an organization's payroll. It involves the rearrangement and reassignment of virtually all employees in an organization.

Drug abuse screening of childbearing-age women in Alabama public health clinics

During August 1989, the urine of 5010 women of childbearing-age in Alabama was screened for marijuana, cocaine, opiates, amphetamines, and barbiturates. The data base consisted of 2970 pregnant women, 374 of whom were at high risk, and 2019 nonpregnant women. Our findings included the following information: (1) The statewide prevalence of positive screens for any drugs tested was 12.9% for all women (11.0% for those who were pregnant and 15.6% for those who were not pregnant). (2) There was no difference between urban and rural groups for any drugs tested. (3) Positive marijuana screens were increased among white and nonpregnant women (p less than 0.01). (4) Positive cocaine screens were increased among black and single women (p less than 0.01). (5) More screens were positive in women older than age 20 (p less than 0.01). (6) There was no difference between pregnant and nonpregnant women for positive cocaine screens. (7) No difference existed among the trimesters of pregnancy for positive cocaine screens. (8) Positive screens for marijuana were more frequent in the first trimester of pregnancy than in the second trimester (p = 0.02) or the third trimester (p = 0.001). (9) There was no difference between high-risk and low-risk maternity patients for any drugs tested.

Gut hormone responses after reconstructive surgery for ulcerative colitis

After colectomy, continent ileal reservoirs are an accepted alternative to conventional ileostomy for patients with ulcerative colitis. To assess the effect of these reservoirs on digestive function, circulating and morphologic gut endocrine responses were measured in patients with a continent ileostomy or with a pelvic pouch and compared to patients with conventional ileostomy, with active ulcerative colitis and healthy controls. Eight subjects were studied in each group. Basal and postprandial plasma gastrin, enteroglucagon, neurotensin, vasoactive intestinal polypeptide, insulin, pancreatic glucagon, and pancreatic polypeptide in both groups with ileal reservoirs were equivalent to controls. Basal plasma motilin and postprandial plasma gastric inhibitory polypeptide were raised in ileal reservoir patients, but similar changes also occurred in ulcerative colitis patients and those with conventional ileostomy. In one half of patients, cell populations of enteroglucagon, peptide YY, and neurotensin were decreased in pouch mucosa that corresponded with the presence of mucosal inflammation. On the other hand, with pouch inflammation vasoactive intestinal polypeptide immunoreactive nerves were increased and a proportion of the fibres were moderately coarsened. Mucosal concentrations of vasoactive intestinal polypeptide did not, however, exceed that of controls. After an ileal reservoir sufficient reserve remains for gut hormone release into the circulation, suggesting compensation for the presence of a reservoir and the absence of a colon; circulating hormone changes do occur but are consequent upon previous ulcerative colitis. Reservoirs may show neuromorphologic alterations that appear to be related to mucosal inflammation.