Mitotic deacetylase complex (MiDAC) recognizes the HIV-1 core promoter to control activated viral gene expression

The human immunodeficiency virus (HIV) integrates into the host genome forming latent cellular reservoirs that are an obstacle for cure or remission strategies. Viral transcription is the first step in the control of latency and depends upon the hijacking of the host cell RNA polymerase II (Pol II) machinery by the 5' HIV LTR. Consequently, "block and lock" or "shock and kill" strategies for an HIV cure depend upon a full understanding of HIV transcriptional control. The HIV trans-activating protein, Tat, controls HIV latency as part of a positive feed-forward loop that strongly activates HIV transcription. The recognition of the TATA box and adjacent sequences of HIV essential for Tat trans-activation (TASHET) of the core promoter by host cell pre-initiation complexes of HIV (PICH) has been shown to be necessary for Tat trans-activation, yet the protein composition of PICH has remained obscure. Here, DNA-affinity chromatography was employed to identify the mitotic deacetylase complex (MiDAC) as selectively recognizing TASHET. Using biophysical techniques, we show that the MiDAC subunit DNTTIP1 binds directly to TASHET, in part via its CTGC DNA motifs. Using co-immunoprecipitation assays, we show that DNTTIP1 interacts with MiDAC subunits MIDEAS and HDAC1/2. The Tat-interacting protein, NAT10, is also present in HIV-bound MiDAC. Gene silencing revealed a functional role for DNTTIP1, MIDEAS, and NAT10 in HIV expression in cellulo. Furthermore, point mutations in TASHET that prevent DNTTIP1 binding block the reactivation of HIV by latency reversing agents (LRA) that act via the P-TEFb/7SK axis. Our data reveal a key role for MiDAC subunits DNTTIP1, MIDEAS, as well as NAT10, in Tat-activated HIV transcription and latency. DNTTIP1, MIDEAS and NAT10 emerge as cell cycle-regulated host cell transcription factors that can control activated HIV gene expression, and as new drug targets for HIV cure strategies.

Resuming elective hip and knee arthroplasty after the first phase of the SARS-CoV-2 pandemic: the European Hip Society and European Knee Associates recommendations

PURPOSE

The Covid-19 pandemic has disrupted health care systems all over the world. Elective surgical procedures have been postponed and/or cancelled. Consensus is, therefore, required related to the factors that need to be in place before elective surgery, including hip and knee replacement surgery, which is restarted. Entirely new pathways and protocols need to be worked out.

METHODS

A panel of experts from the European Hip Society and European Knee Association have agreed to a consensus statement on how to reintroduce elective arthroplasty surgery safely. The recommendations are based on the best available evidence and have been validated in a separate survey.

RESULTS

The guidelines are based on five themes: modification and/or reorganisation of hospital wards. Restrictions on orthopaedic wards and in operation suite(s). Additional disinfection of the environment. The role of ultra-clean operation theatres. Personal protective equipment enhancement.

CONCLUSION

Apart from the following national and local guidance, protocols need to be put in place in the patient pathway for primary arthroplasty to allow for a safe return.

Recommendations for resuming elective hip and knee arthroplasty in the setting of the SARS-CoV-2 pandemic: the European Hip Society and European Knee Associates Survey of Members

PURPOSE

The COVID-19 pandemic has disrupted the health care system around the entire globe. A consensus is needed about resuming total hip and knee procedures. The European Hip Society (EHS) and the European Knee Association (EKA) formed a panel of experts that have produced a consensus statement on how the safe re-introduction of elective hip and knee arthroplasty should be undertaken.

METHODS

A prospective online survey was done among members of EHS and EKA. The survey consisted of 27 questions. It includes basic information on demographics and details the participant's agreement with each recommendation. The participant could choose among three options (agree, disagree, abstain). Recommendations focussed on pre-operative, peri-operative, and post-operative handling of patients and precautions.

RESULTS

A total of 681 arthroplasty surgeons participated in the survey, with 479 fully completing the survey. The participants were from 44 countries and 6 continents. Apart from adhering to National and Local Guidelines, the recommendations concerned how to make elective arthroplasty safe for patients and staff.

CONCLUSION

The survey has shown good-to-excellent agreement of the participants with regards to the statements made in the recommendations for the safe return to elective arthroplasty following the first wave of the COVID-19 pandemic.

Driving safety improves after individualized training: An RCT involving older drivers in an urban area

Objective: This study aimed to reproduce the results of a previous investigation on the safety benefits of individualized training for older drivers. We modified our method to address validity and generalizability issues. Methods: Older drivers were randomly assigned to one of the 3 arms: (1) education alone, (2) education + on road training, and (3) education + on road + simulator training. Older drivers were recruited from a larger urban community. At the pre- and posttests (separated by 4 to 8 weeks) participants followed driving directions using a Global Positioning System (GPS) navigation system. Results: Our findings support the positive influence of individualized on-road training for urban-dwelling older drivers. Overall, driving safety improved among drivers who received on-road training over those who were only exposed to an education session, F(1, 40) = 11.66, P = .001 (26% reduction in total unsafe driving actions [UDAs]). Statistically significant improvements were observed on observation UDAs (e.g., scanning at intersections, etc.), compliance UDAs (e.g., incomplete stop), and procedural UDAs (e.g., position in lane). Conclusion: This study adds to the growing evidence base in support of individualized older driver training to optimize older drivers' safety and promote continued safe driving.

Provisional Educational Needs of Health Care Providers in Palliative Care in Three Nursing Homes in Ontario

Health care providers in three nursing homes in Ontario were surveyed to determine educational needs, barriers to meeting these needs, and the preferred format for education. Of the 415 health care providers asked to participate, 225 completed the questionnaire. Need was expressed for the majority of the 35 educational topics identified, including the role of the palliative care team, management of physical symptoms, pharmacological and non-pharmacological management of pain, stress management, spiritual needs, culture and death, and counseling. Group discussions and seminars were favored over traditional lectures. The primary factors influencing attendance at a palliative care workshop were loss of pay and time and location of the workshop.

A versatile papaya mosaic virus (PapMV) vaccine platform based on sortase-mediated antigen coupling

Background

Flexuous rod-shaped nanoparticles made of the coat protein (CP) of papaya mosaic virus (PapMV) have been shown to trigger innate immunity through engagement of toll-like receptor 7 (TLR7). PapMV nanoparticles can also serve as a vaccine platform as they can increase the immune response to fused peptide antigens. Although this approach shows great potential, fusion of antigens directly to the CP open reading frame (ORF) is challenging because the fused peptides can alter the structure of the CP and its capacity to self assemble into nanoparticles—a property essential for triggering an efficient immune response to the peptide. This represents a serious limitation to the utility of this approach as fusion of small peptides only is tolerated.

Results

We have developed a novel approach in which peptides are fused directly to pre-formed PapMV nanoparticles. This approach is based on the use of a bacterial transpeptidase (sortase A; SrtA) that can attach the peptide directly to the nanoparticle. An engineered PapMV CP harbouring the SrtA recognition motif allows efficient coupling. To refine our engineering, and to predict the efficacy of coupling with SrtA, we modeled the PapMV structure based on the known structure of PapMV CP and on recent reports revealing the structure of two closely related potexviruses: pepino mosaic virus (PepMV) and bamboo mosaic virus (BaMV). We show that SrtA can allow the attachment of long peptides [Influenza M2e peptide (26 amino acids) and the HIV-1 T20 peptide (39 amino acids)] to PapMV nanoparticles. Consistent with our PapMV structural model, we show that around 30% of PapMV CP subunits in each nanoparticle can be fused to the peptide antigen. As predicted, engineered nanoparticles were capable of inducing a strong antibody response to the fused antigen. Finally, in a challenge study with influenza virus, we show that mice vaccinated with PapMV-M2e are protected from infection.

Conclusions

This technology will allow the development of vaccines harbouring long peptides containing several B and/or T cell epitopes that can contribute to a broad and robust protection from infection. The design can be fast, versatile and can be adapted to the development of vaccines for many infectious diseases as well as cancer vaccines.

Electronic supplementary material

The online version of this article (doi:10.1186/s12951-017-0289-y) contains supplementary material, which is available to authorized users.

Biophysical characterization of the b-HLH-LZ of ΔMax, an alternatively spliced isoform of Max found in tumor cells: Towards the validation of a tumor suppressor role for the Max homodimers

It is classically recognized that the physiological and oncogenic functions of Myc proteins depend on specific DNA binding enabled by the dimerization of its C-terminal basic-region-Helix-Loop-Helix-Leucine Zipper (b-HLH-LZ) domain with that of Max. However, a new paradigm is emerging, where the binding of the c-Myc/Max heterodimer to non-specific sequences in enhancers and promoters drives the transcription of genes involved in diverse oncogenic programs. Importantly, Max can form a stable homodimer even in the presence of c-Myc and bind DNA (specific and non-specific) with comparable affinity to the c-Myc/Max heterodimer. Intriguingly, alterations in the Max gene by germline and somatic mutations or changes in the gene product by alternative splicing (e.g. ΔMax) were recently associated with pheochromocytoma and glioblastoma, respectively. This has led to the proposition that Max is, by itself, a tumor suppressor. However, the actual mechanism through which it exerts such an activity remains to be elucidated. Here, we show that contrary to the WT motif, the b-HLH-LZ of ΔMax does not homodimerize in the absence of DNA. In addition, although ΔMax can still bind the E-box sequence as a homodimer, it cannot bind non-specific DNA in that form, while it can heterodimerize with c-Myc and bind E-box and non-specific DNA as a heterodimer with high affinity. Taken together, our results suggest that the WT Max homodimer is important for attenuating the binding of c-Myc to specific and non-specific DNA, whereas ΔMax is unable to do so. Conversely, the splicing of Max into ΔMax could provoke an increase in overall chromatin bound c-Myc. According to the new emerging paradigm, the splicing event and the stark reduction in homodimer stability and DNA binding should promote tumorigenesis impairing the tumor suppressor activity of the WT homodimer of Max.

Structural Insights into c-Myc-interacting Zinc Finger Protein-1 (Miz-1) Delineate Domains Required for DNA Scanning and Sequence-specific Binding

c-Myc-interacting zinc finger protein-1 (Miz-1) is a poly-Cys2His2 zinc finger (ZF) transcriptional regulator of many cell cycle genes. A Miz-1 DNA sequence consensus has recently been identified and has also unveiled Miz-1 functions in other cellular processes, underscoring its importance in the cell. Miz-1 contains 13 ZFs, but it is unknown why Miz-1 has so many ZFs and whether they recognize and bind DNA sequences in a typical fashion. Here, we used NMR to deduce the role of Miz-1 ZFs 1-4 in detecting the Miz-1 consensus sequence and preventing nonspecific DNA binding. In the construct containing the first 4 ZFs, we observed that ZFs 3 and 4 form an unusual compact and stable structure that restricts their motions. Disruption of this compact structure by an electrostatically mismatched A86K mutation profoundly affected the DNA binding properties of the WT construct. On the one hand, Miz1-4^WT was found to bind the Miz-1 DNA consensus sequence weakly and through ZFs 1-3 only. On the other hand, the four ZFs in the structurally destabilized Miz1-4^A86K mutant bound to the DNA consensus with a 30-fold increase in affinity (100 nm). The formation of such a thermodynamically stable but nonspecific complex is expected to slow down the rate of DNA scanning by Miz-1 during the search for its consensus sequence. Interestingly, we found that the motif stabilizing the compact structure between ZFs 3 and 4 is conserved and enriched in other long poly-ZF proteins. As discussed in detail, our findings support a general role of compact inter-ZF structures in minimizing the formation of off-target DNA complexes.

Miz-1 and Max compete to engage c-Myc: implication for the mechanism of inhibition of c-Myc transcriptional activity by Miz-1

c-Myc is a basic helix-loop-helix leucine zipper (b-HLH-LZ) transcription factor deregulated in the majority of human cancers. As a heterodimer with Max, another b-HLH-LZ transcription factor, deregulated and persistent c-Myc accumulates at transcriptionally active promoters and enhancers and amplifies transcription. This leads to the so-called transcriptional addiction of tumor cells. Recent studies have showed that c-Myc transcriptional activities can be reversed by its association with Miz-1, a POZ transcription factor containing 13 classical zinc fingers. Although evidences have led to suggest that c-Myc interacts with both Miz-1 and Max to form a ternary repressive complex, earlier evidences also suggest that Miz-1 and Max may compete to engage c-Myc. In such a scenario, the Miz-1/c-Myc complex would be the entity responsible for the inhibition of c-Myc transcriptional amplification. Considering the implications of the Miz-1/c-Myc interaction, it is highly important to solve this duality. While two potential c-Myc interacting domains (hereafter termed MID) have been identified in Miz-1 by yeast two-hybrid, with the b-HLH-LZ as a bait, the biophysical characterization of these interactions has not been reported so far. Here, we report that the MID located between the 12th and 13th zinc finger of Miz-1 and the b-HLH-LZ of Max compete to form a complex with the b-HLH-LZ of c-Myc. Our results support the notion that the repressive action of Miz-1 on c-Myc does not rely on the formation of a ternary complex. The implications of these observations for the mechanism of inhibition of c-Myc transcriptional activity by Miz-1 are discussed. Proteins 2017; 85:199-206. © 2016 Wiley Periodicals, Inc.

Structure, Dynamics, and Interaction of p54(nrb)/NonO RRM1 with 5' Splice Site RNA Sequence

p54(nrb)/NonO is a nuclear RNA-binding protein involved in many cellular events such as pre-mRNA processing, transcription, and nuclear retention of hyper-edited RNAs. In particular, it participates in the splicing process by directly binding the 5' splice site of pre-mRNAs. The protein also concentrates in a nuclear body called paraspeckle by binding a G-rich segment of the ncRNA NEAT1. The N-terminal section of p54(nrb)/NonO contains tandem RNA recognition motifs (RRMs) preceded by an HQ-rich region including a threonine residue (Thr15) whose phosphorylation inhibits its RNA binding ability, except for G-rich RNAs. In this work, our goal was to understand the rules that characterize the binding of the p54(nrb)/NonO RRMs to their RNA target. We have done in vitro RNA binding experiments which revealed that only the first RRM of p54(nrb)/NonO binds to the 5' splice site RNA. We have then determined the structure of the p54(nrb)/NonO RRM1 by liquid-state NMR which revealed the presence of a canonical fold (β1α1β2β3α2β4) and the conservation of aromatic amino acids at the protein surface. We also investigated the dynamics of this domain by NMR. The p54(nrb)/NonO RRM1 displays some motional properties that are typical of a well-folded protein with some regions exhibiting more flexibility (loops and β-strands). Furthermore, we determined the affinity of p54(nrb)/NonO RRM1 interaction to the 5' splice site RNA by NMR and fluorescence quenching and mapped its binding interface by NMR, concluding in a classical nucleic acid interaction. This study provides an improved understanding of the molecular basis (structure and dynamics) that governs the binding of the p54(nrb)/NonO RRM1 to one of its target RNAs.

Solution structure of the 13th C2H2 Zinc Finger of Miz-1

Miz-1 is a BTB/POZ transcription factor that contains 13C2H2 Zinc Finger domains (ZF). Miz-1 transactivates and represses the transcription of a myriad of genes involved in many aspects of the biology of the cell. The detailed molecular interactions through which Miz-1 controls transcription, including its specific DNA binding via its ZF domains, remain to be understood and documented. In our effort to shed light into the structural biology of Miz-1, we have undertaken the determination of the structure of all its ZF and the characterization of their interactions with cognate DNA. The structure of ZF 1 to 10 have already been solved and characterized. Here, we present the structure of the synthetic Miz-1 ZF13 determined by 2D (1)H-(1)H NMR.

Bilateral distal fibula fractures in a woman on long-term bisphosphonate therapy

We report the case of a 53-year-old female, treated by bisphosphonate for 12 years, who presented atraumatic fractures of both fibulas. Her X-rays showed bilateral distal fibula fractures with radiological features similar to atypical femur fractures. The distal fibula should be considered as a potential site for stress fractures in bisphosphonate users. Bisphosphonates are the most widely used drugs in the treatment of osteoporosis. During the last decade, the occurrence of atypical fractures, mostly subtrochanteric and diaphyseal femoral fractures, has been acknowledged in patients with long-term use of bisphosphonates. We report the case of a 53-year-old female on alendronate therapy for the past 12 years who presented with a few months history of atraumatic right, and subsequently left, lateral ankle pain. Her X-rays showed bilateral distal fibula fractures with radiological features similar to atypical femur fractures. She had been treated conservatively with walking boots and her treatment with bisphosphonate had been stopped 5 months prior to the fractures. Callus was progressively seen on serial follow-up X-rays, and both fractures healed completely within a reasonable period of 1 year. Investigations did not reveal any secondary causes of osteoporosis or metabolic bone disorders. To our knowledge, this is the first reported case of bilateral distal fibula fractures in a patient on long-term bisphosphonate therapy.

An international study of the quality of national-level guidelines on driving with medical illness

BACKGROUND

Medical illnesses are associated with a modest increase in crash risk, although many individuals with acute or chronic conditions may remain safe to drive, or pose only temporary risks. Despite the extensive use of national guidelines about driving with medical illness, the quality of these guidelines has not been formally appraised.

AIM

To systematically evaluate the quality of selected national guidelines about driving with medical illness.

DESIGN

A literature search of bibliographic databases and Internet resources was conducted to identify the guidelines, each of which was formally appraised.

METHODS

Eighteen physicians or researchers from Canada, Australia, Ireland, USA and UK appraised nine national guidelines, applying the Appraisal of Guidelines for Research and Evaluation (AGREE II) instrument.

RESULTS

Relative strengths were found in AGREE II scores for the domains of scope and purpose, stakeholder involvement and clarity of presentation. However, all guidelines were given low ratings on rigour of development, applicability and documentation of editorial independence. Overall quality ratings ranged from 2.25 to 5.00 out of 7.00, with modifications recommended for 7 of the guidelines. Intra-class coefficients demonstrated fair to excellent appraiser agreement (0.57-0.79).

CONCLUSIONS

This study represents the first systematic evaluation of national-level guidelines for determining medical fitness to drive. There is substantive variability in the quality of these guidelines, and rigour of development was a relative weakness. There is a need for rigorous, empirically derived guidance for physicians and licensing authorities when assessing driving in the medically ill.

The influences of psychotic symptoms on the activities of daily living of individuals with Alzheimer disease: a longitudinal analysis

OBJECTIVES

Psychotic symptoms associated with Alzheimer Disease (AD) contribute to excess functional dependence. Longitudinal studies have generally examined the association between rates of functional decline and the occurrence of psychotic symptoms from either a single evaluation or from multiple evaluations rather than through changes in frequency and severity of symptoms. Although the presence or absence of psychotic symptoms at initial or follow-up examinations may be associated with changes in functional status, the nature of the relationship between changes in these domains cannot be inferred. We examine the association between changes in the frequency of psychotic symptoms and changes in dependence in activities of daily living (ADL) over a period ranging from 1 to 74 months (median = 17.7).

METHOD

Data from a cohort of 234 individuals referred to a memory clinic were analyzed using multilevel linear regression. Information on ADL, behavioral and psychological symptoms, depression, and cognition was collected.

RESULTS

An increase in the frequency of psychotic symptoms had a unique influence on the deterioration of basic ADL, after controlling for demographic variables, changes in cognition, depression, and other behavioral and psychological symptoms (B = -.017, p = .003). However, changes in psychotic symptoms did not significantly contribute to declines in the ability to perform instrumental ADL (B = -.008, p = .439).

CONCLUSION

Changes in psychotic symptoms may influence basic but not instrumental ADL over time. These findings may have ramifications for studies and treatment plans for individuals with AD who demonstrate psychotic symptoms.

Structural and dynamical characterization of the Miz-1 zinc fingers 5-8 by solution-state NMR

Myc-interacting zinc finger protein-1 (Miz-1) is a BTB/POZ transcription factor that activates the transcription of cytostatic genes, such as p15(INK4B) or p21(CIP1). The C-terminus of Miz-1 contains 13 consensus C2H2 zinc finger domains (ZF). ZFs 1-4 have been shown to interact with SMAD3/4, while the remaining ZFs are expected to bind the promoters of target genes. We have noted unusual features in ZF 5 and the linker between ZFs 5 and 6. Indeed, a glutamate is found instead of the conserved basic residue two positions before the second zinc-coordinating histidine on the ZF 5 helix, and the linker sequence is DTDKE in place of the classical TGEKP sequence. In a canonical ββα fold, such unusual primary structure elements should cause severe electrostatic repulsions. In this context, we have characterized the structure and the dynamics of a Miz-1 construct comprising ZFs 5-8 (Miz 5-8) by solution-state NMR. Whilst ZFs 5, 7 and 8 were shown to adopt the classical ββα fold for C2H2 ZFs, the number of long-range NOEs was insufficient to define a classical fold for ZF 6. We show by using (15)N-relaxation dispersion experiments that this lack of NOEs is due to the presence of extensive motions on the μs-ms timescale. Since this negatively charged region would have to be located near the phosphodiester backbone in a DNA complex, we propose that in addition to promoting conformational searches, it could serve as a hinge region to keep ZFs 1-4 away from DNA.

Methods for the expression, purification, preparation, and biophysical characterization of constructs of the c-Myc and Max b-HLH-LZs

Specific heterodimerization and DNA binding by the b-HLH-LZ transcription factors c-Myc and Max is central to the activation and repression activities of c-Myc that lead to cell growth, proliferation, and tumorigenesis (Adhikary and Eilers, Nat Rev Mol Cell Biol 6:635-645, 2005; Eilers and Eisenman, Genes Dev 22:2755-2766, 2008; Grandori et al., Annu Rev Cell Dev Biol 16:653-699, 2000; Whitfield and Soucek, Cell Mol Life Sci 69:931-934, 2011). Although many c-Myc-interacting partner proteins are known to interact through their HLH domain (Adhikary and Eilers, Nat Rev Mol Cell Biol 6:635-645, 2005), current knowledge regarding the structure and the determinants of molecular recognition of these complexes is still very limited. Moreover, recent advances in the development and use of b-HLH-LZ dominant negatives (Soucek et al., Nature 455:679-683, 2008) and inhibitors of c-Myc interaction with its protein partners (Bidwell et al., J Control Release 135:2-10, 2009; Mustata et al., J Med Chem 52:1247-1250, 2009; Prochownik and Vogt, Genes Cancer 1:650-659, 2010) or DNA highlight the importance of efficient protocols to prepare such constructs and variants. Here, we provide methods to produce and purify high quantities of pure and untagged b-HLH-LZ constructs of c-Myc and Max as well as specific c-Myc/Max heterodimers for their biophysical and structural characterization by CD, NMR, or crystallography. Moreover, biochemical methods to analyze the homodimers and heterodimers as well as DNA binding of these constructs by native electrophoresis are presented. In addition to enable the investigation of the c-Myc/Max b-HLH-LZ complexes, the protocols described herein can be applied to the biochemical characterization of various mutants of either partner, as well as to ternary complexes with other partner proteins.

The mitotic phosphorylation of p54nrb modulates its RNA binding activity

The RNA-binding protein p54nrb is involved in many nuclear processes including transcription, RNA processing, and retention of hyperedited RNAs. In interphase cells, p54nrb localizes to the nucleoplasm and concentrates with protein partners in the paraspeckles via an interaction with the non-coding RNA Neat1. During mitosis, p54nrb becomes multiphosphorylated and the effects of this modification are not known. In the present study, we show that p54nrb phosphorylation does not affect the interactions with its protein partners but rather diminishes its general RNA-binding ability. Biochemical assays indicate that in vitro phosphorylation of a GST-p54nrb construct by CDK1 abolishes the interaction with 5′ splice site RNA sequence. Site-directed mutagenesis shows that the threonine 15 residue, located N-terminal to the RRM tandem domains of p54nrb, is involved in this inhibition. In vivo analysis reveals that Neat1 ncRNA co-immunoprecipitates with p54nrb in either interphase or mitotic cells, suggesting that p54nrb–Neat1 interaction is not modulated by phosphorylation. Accordingly, in vitro phosphorylated GST-p54nrb still interacts with PIR-1 RNA, a G-rich Neat1 sequence known to interact with p54nrb. In vitro RNA binding assays show that CDK1-phosphorylation of a GST-p54nrb construct abolishes its interaction with homoribopolymers poly(A), poly(C), and poly(U) but not with poly(G). These data suggest that p54nrb interaction with RNA could be selectively modulated by phosphorylation during mitosis.

Does condition of Atlantic cod (Gadus morhua) have a greater impact upon swimming performance at Ucrit or sprint speeds?

To compare the sensitivity of sprint and critical (Ucrit) swimming speeds to the condition of Atlantic cod (Gadus morhua) and to identify the best anatomic, behavioural and biochemical correlates of these types of swimming, we established two groups of cod that were fed or starved for 12 weeks. We evaluated sprint swimming and Ucrit performance as well as the speed at which repeated burst-coast movements began in the Ucrit test before measuring the metabolic capacities of red and white muscle sampled caudally, centrally and rostrally and the anatomic characteristics of the cod. White muscle lactate was measured directly after the Ucrit test. As expected, the twofold difference in Fulton's condition factor (0.5+/-0.04 for starved and 1.0+/-0.1 for fed cod) was accompanied by large differences in the anatomic and biochemical parameters measured. Despite the relative sparing of muscle aerobic capacity during starvation and despite the greater use of oxidative fibres during Ucrit compared with sprint swimming, these types of swimming differed by much the same extent between starved and fed cod. In the Ucrit tests, white muscle lactate levels and lactate accumulation per burst-coast movement were considerably higher in fed than starved cod, suggesting more intensive use of fast muscle fibres in cod in good condition. Multiple regression analysis indicated strong correlations between Ucrit, the speed at which regular burst-coasting began and the activity of pyruvate dehydrogenase (PDH) in red muscle (both caudal and central positions). PDH activity may limit the rate of oxidative ATP production by red muscle. The activity of cytochrome c oxidase in rostral white muscle was the strongest correlate of sprint swimming, suggesting that aerobic preparation of white muscle facilitates rapid contraction. The correlation between Ucrit and sprint swimming was weak, perhaps due to inter-individual differences in sensitivity during sprint tests.

Caregiving and its impact on families of the terminally ill

Changes in the health care system have meant that increasing numbers of the terminally ill receive the majority of their care at home. The purpose of this paper was to document patterns of informal and formal care provided to the terminally ill and assess the impact caregiving has on family members. One hundred and fifty-one family caregivers were recruited for interviews from two community-nursing agencies in an urban region of the province of Ontario, Canada. The majority of respondents 119 (79%) were the female spouses of the patient. The numbers of caregivers providing assistance in specific functional activities were: bathing, 133 (88%); mobility, 123 (81%); dressing and undressing, 114 (76%); toileting, 101(67%), and assistance at night 97 (64%). Sixty-two (41%) respondents reported that they had been providing some form of caregiving for over one year. They also reported that physical demands in caregiving increased substantially during the last three months of the care recipient's life. As family caregivers provided more assistance in activities of daily living they were at greater risk of reporting high caregiver burden. The results of this paper identify the types of care provided by family caregivers of the terminally ill and the impact these demands have on the family caregiver.

Traffic-related fatalities among older drivers and passengers: past and future trends

PURPOSE OF THE STUDY

This study was initiated to forecast the number of older drivers and passengers who may be fatally injured in traffic crashes in future years.

DESIGN AND METHODS

The study was based on data from the U.S. Fatality Analysis Reporting System covering the period from 1975 to 1998. Projections were based on least squares regression models.

RESULTS

About 35,000 drivers and passengers died in traffic crashes each year from 1975 to 1998. Older adults (65 and older) accounted for 10% of all fatalities in 1975, 17% in 1998, and a projected 27% by 2015, the same proportion predicted for drivers and passengers aged younger than 30. On the basis of these projections, the number of fatally injured women and men aged 65 and older will increase respectively by 373% and 271% between 1975 and 2015.

IMPLICATIONS

If current trends continue, the number of fatalities among older drivers and passengers and those aged younger than 30, may be equivalent early in this century. These projections call for further research into conditions that may lead to crashes involving older drivers and for the development and implementation of initiatives to curb traffic-related fatalities among older adults.

The Zarit Burden Interview: a new short version and screening version

PURPOSE

The purpose of the study was to develop a short and a screening version of the Zarit Burden Interview (ZBI) that would be suitable across diagnostic groups of cognitively impaired older adults, and that could be used for cross-sectional, longitudinal, and intervention studies.

DESIGN AND METHODS

We used data from 413 caregivers of cognitively impaired older adults referred to a memory clinic. We collected information on caregiver burden with the 22-item ZBI, and information about dependence in activities of daily living (ADLs) and the frequency of problem behaviors among care recipients. We used factor analysis and item-total correlations to reduce the number of items while taking into consideration diagnosis and change scores.

RESULTS

We produced a 12-item version (short) and a 4-item version (screening) of the ZBI. Correlations between the short and the full version ranged from 0.92 to 0.97, and from 0.83 to 0.93 for the screening version. Correlations between the three versions and ADL and problem behaviors were similar. We further investigated the behavior of the short version with a two-way analysis of variance and found that it produced identical results to the full version.

IMPLICATIONS

The short and screening versions of the ZBI produced results comparable to those of the full version. Reducing the number of items did not affect the properties of the ZBI, and it may lead to easier administration of the instrument.

The Zarit Burden Interview: a new short version and screening version

PURPOSE

The purpose of the study was to develop a short and a screening version of the Zarit Burden Interview (ZBI) that would be suitable across diagnostic groups of cognitively impaired older adults, and that could be used for cross-sectional, longitudinal, and intervention studies.

DESIGN AND METHODS

We used data from 413 caregivers of cognitively impaired older adults referred to a memory clinic. We collected information on caregiver burden with the 22-item ZBI, and information about dependence in activities of daily living (ADLs) and the frequency of problem behaviors among care recipients. We used factor analysis and item-total correlations to reduce the number of items while taking into consideration diagnosis and change scores.

RESULTS

We produced a 12-item version (short) and a 4-item version (screening) of the ZBI. Correlations between the short and the full version ranged from 0.92 to 0.97, and from 0.83 to 0.93 for the screening version. Correlations between the three versions and ADL and problem behaviors were similar. We further investigated the behavior of the short version with a two-way analysis of variance and found that it produced identical results to the full version.

IMPLICATIONS

The short and screening versions of the ZBI produced results comparable to those of the full version. Reducing the number of items did not affect the properties of the ZBI, and it may lead to easier administration of the instrument.

Development of a standardized, comprehensive "ideal drug detail"

OBJECTIVES

To develop a standardized, comprehensive ideal drug detail for use in face-to-face education about individual drugs.

METHODS

A random sample of 603 physicians and pharmacists was selected and stratified to include input from each of the following specialties: family practice, internal medicine, surgery, pediatrics, psychiatry, obstetrics/gynecology, geriatric medicine and clinical pharmacology. Thirty-one potential items were generated by the investigators from a preliminary survey of a local convenience sample of physicians and pharmacists. A modified Delphi consensus process was used in the large sample to determine which items should be included in the ideal drug detail. In each round of the Delphi process, respondents rated each item on a seven-point scale of importance and were then given feedback of the cumulative ratings for each item. Rounds were continued until consensus was obtained on all items.

RESULTS

The response rate to the first round was 55.3%; 85.5% of these respondents responded to the second round. Response rates varied between specialties from 44% to 70%. Attempts to contact nonresponders to measure potential nonrespondent bias were unsuccessful. Consensus was obtained on 19 items after the first round, and on the remaining 12 items after the second round. Four items were dropped because they were unimportant. There was variation in modal response between specialties on eight items.

CONCLUSIONS

Consensus was obtained among a sizable and interested sample of Canadian physicians and pharmacists on the items of information needed to prescribe a drug appropriately. Subsequent work will refine this list into a usable template to develop ideal drug details for specific drugs, to develop an assessment process to measure quality of information, and to assess the impact of this program on prescribing and patient outcomes.

Lengthy hospitalization associated with vertebral fractures despite control for comorbid conditions

This study established whether length of hospital stay (LOS) in Canadians 50 years and older is attributable to their vertebral fractures versus comorbid conditions. The study used a case-control design and data in the Canadian Institute for Health Information (CIHI) database on hospital discharges in Ontario, Alberta, and British Columbia between April 1, 1996 and March 31, 1997. Patients with vertebral fractures were identified by International Classification of Diseases (ICD-9) codes. LOS constituted the dependent measure in a multivariate linear regression that calculated the independent contributions to LOS by vertebral fractures while controlling for: age, gender, province, discharged deceased, hip fractures, all other fractures, motor vehicle accidents, all other injuries, and the major disorder classifications in ICD-9. Mean LOS for all patients admitted for vertebral fractures was 10.1 days. LOS attributed solely to vertebral fractures was 4.8 days based on a 50-year-old woman with no comorbid conditions, and 6.1 days based on a 75-year-old woman. Of 18 health conditions, vertebral fractures were among the top 3 in accounting for LOS, along with hip fractures and mental disorders which accounted for 5.9 days and 6.1 days in a 50-year-old woman. Among patients admitted for other problems, comorbid vertebral fractures added 2.1 days. These findings indicate that hospital stays for vertebral fractures are lengthy despite control for comorbidity.

Assessment of adherence to renal dosing guidelines in long-term care facilities

OBJECTIVE

We determined whether dosing guidelines based on creatinine clearance (Ccr) for renally excreted drugs are being applied when prescribing to long-term care residents

DESIGN

A cross sectional chart review for the month of May 1999.

PARTICIPANTS

Long-term care residents more than 65 years of age from four long-term care facilities in Southern Ontario who were prescribed a medication from a list of renally excreted drugs commonly prescribed in long-term care facilities.

RESULTS

Approximately one in three prescriptions (34.1%) were considered inappropriate for the calculated Ccr of the residents. Overall, 42.3% of the residents who were prescribed a drug under review received at least one inappropriate prescription based on creatinine clearance. Logistic regression found that age (odds ratio (OR) = 1.06 per year; 95% confidence interval (CI) 1.03-1.09, P = .001), weight (OR = 0.96 per kg; 95% CI 0.94-0.98, P < .001), the total number of prescribed medications (OR = 1.10; 95% CI 1.04-1.17, P = .001), and the number of physicians prescribing in the facility (OR 1.02; 95% CI, 1.003-1.044, P = .03) were predictive for receiving an inappropriate prescription based on Ccr.

CONCLUSIONS

Renal function is often overlooked when prescribing renally excreted drugs to older long-term care residents. These findings emphasize the need for consideration of Ccr when prescribing such drugs in this population.

Assessing reproducibility of data obtained with instruments based on continuous measurements

Data obtained with any research tool must be reproducible, a concept referred to as reliability. Three techniques are often used to evaluate reliability of tools using continuous data in aging research: intraclass correlation coefficients (ICC), Pearson correlations, and paired t tests. These are often construed as equivalent when applied to reliability. This is not correct, and may lead researchers to select instruments based on statistics that may not reflect actual reliability. The purpose of this paper is to compare the reliability estimates produced by these three techniques and determine the preferable technique. A hypothetical dataset was produced to evaluate the reliability estimates obtained with ICC, Pearson correlations, and paired t tests in three different situations. For each situation two sets of 20 observations were created to simulate an intrarater or inter-rater paradigm, based on 20 participants with two observations per participant. Situations were designed to demonstrate good agreement, systematic bias, or substantial random measurement error. In the situation demonstrating good agreement, all three techniques supported the conclusion that the data were reliable. In the situation demonstrating systematic bias, the ICC and t test suggested the data were not reliable, whereas the Pearson correlation suggested high reliability despite the systematic discrepancy. In the situation representing substantial random measurement error where low reliability was expected, the ICC and Pearson coefficient accurately illustrated this. The t test suggested the data were reliable. The ICC is the preferred technique to measure reliability. Although there are some limitations associated with the use of this technique, they can be overcome.

Burden in caregivers of cognitively impaired older adults living in the community: methodological issues and determinants

Considerable burden is reported by informal caregivers of older individuals with cognitive impairment. Significant progress in the understanding of determinants of this burden has been achieved. However, further progress could be attained if we considered important methodological issues that may have limited our understanding of caregiver burden. These issues include subgroups of care recipients and caregivers, measurement issues, research design, and statistical techniques. Fifty-three studies published between 1980 and 1997 (inclusive) that focused on caregiver burden were abstracted to determine the extent to which the methodological issues discussed above were considered. Overall, we found considerable variability among the studies surveyed. Further understanding of the caregiving process and reductions in caregiver burden will depend on the attention to methodological issues and understanding of burden across the whole caregiving career.

Leukotomy revisited: late cognitive and behavioral effects in chronic institutionalized schizophrenics

BACKGROUND

In the 1940s and 1950s, prefrontal lobotomy was widely used to treat aggressive, disruptive and psychotic behavior in schizophrenics. Subsequent observations have confirmed its ineffectiveness in schizophrenia. Few studies have addressed its long-term consequences.

METHODS

We conducted tests of frontal function, behavior (Frontal Behavioral Inventory), psychopathology (PANSS), neurological examinations and CT scans in 19 chronically institutionalized schizophrenic patients (mean age 74) who had undergone orbitofrontal leukotomy between 1948 and 1972 and 11 controls (mean age 74) matched for age, length of hospitalization, education, and diagnosis.

RESULTS

There were no significant differences between leukotomized patients and controls on: Folstein Mini-Mental score (leuko 22.13+/-5.66; controls 23.55+/-5.93), utilization behavior, Luria alternating written and motor sequences, verbal fluency, imitation behavior, motor impersistence, primitive reflexes, or psychopathology. Significant differences were found on clock drawing and on the go/no-go test, which may reflect the presence of an orbitofrontal lesion in the leukotomized group. There was a tendency for the leukotomized group to have fewer indices of frontal behavioral dysfunction. Both groups showed comparable impairment on the Stroop test and cognitive rigidity on the Odd Man Out test of category shifting.

CONCLUSIONS

With few exceptions, elderly leukotomized and nonleukotomized schizophrenic patients show varying degrees of distractibility, difficulty in set shifting, poor planning and organization, susceptibility to interference, primitive reflexes and signs of global cognitive impairment. Allowing for the small sample size, variability in the surgical frontal lesion, and the long interval from surgery to testing, these observations likely reflect the long-term consequences of severe schizophrenia in both groups.

Implementation of advance directives among community-dwelling veterans

To evaluate the feasibility and effectiveness of implementing a "Let Me Decide" advance directive education program among veterans living in the community, the authors studied 150 veterans in south central Ontario. Thirty-four veterans had preexisting Powers of Attorney and were removed from the analysis, leaving a total sample of 116. Two methods of systematically implementing a directive program were evaluated after the intervention period and 6 months later. Eighty-two (71%) of the 116 veterans expressed interest in receiving detailed information about the program, and 67 (82%) of the 82 interested veterans were educated. Forty-two (63%) of the 67 educated veterans completed directives. Of the 116 interested veterans, 42 (36%) completed directives. Veterans who were educated about directives were surveyed at follow-up, and 37 of 38 (97%) respondents reported that the education process was beneficial and should be offered to other veterans. This response pattern was consistent among those who completed and those who did not complete directives.

Systematic implementation of an advance directive program in nursing homes: a randomized controlled trial

CONTEXT

Although advance directives are commonly used in the community, little is known about the effects of their systematic implementation.

OBJECTIVES

To examine the effect of systematically implementing an advance directive in nursing homes on patient and family satisfaction with involvement in decision making and on health care costs.

DESIGN

Randomized controlled trial conducted June 1, 1994, to August 31, 1998.

SETTING AND PARTICIPANTS

A total of 1292 residents in 6 Ontario nursing homes with more than 100 residents each.

INTERVENTION

The Let Me Decide advance directive program included educating staff in local hospitals and nursing homes, residents, and families about advance directives and offering competent residents or next-of-kin of mentally incompetent residents an advance directive that provided a range of health care choices for life-threatening illness, cardiac arrest, and nutrition. The 6 nursing homes were pair-matched on key characteristics, and 1 home per pair was randomized to take part in the program. Control nursing homes continued with prior policies concerning advance directives.

MAIN OUTCOME MEASURES

Residents' and families' satisfaction with health care and health care services utilization over 18 months, compared between intervention and control nursing homes.

RESULTS

Of 527 participating residents in intervention nursing homes, 49% of competent residents and 78% of families of incompetent residents completed advance directives. Satisfaction was not significantly different in intervention and control nursing homes. The mean difference (scale, 1-7) between intervention and control homes was -0.16 (95 % confidence interval [CI], -0.41 to 0.10) for competent residents and 0.07 (95% CI, -0.08 to 0.23) for families of incompetent residents. Intervention nursing homes reported fewer hospitalizations per resident (mean, 0.27 vs 0.48; P = .001) and less resource use (average total cost per patient, Can $3490 vs Can $5239; P = .01) than control nursing homes. Proportion of deaths in intervention (24%) and control (28%) nursing homes were similar (P = .20).

CONCLUSION

Our data suggest that systematic implementation of a program to increase use of advance directives reduces health care services utilization without affecting satisfaction or mortality.

Determinants and detection of low body mass index in community-dwelling adults with Alzheimer's disease

OBJECTIVE

To determine the proportion of older adults with Alzheimer's disease presenting to a geriatric clinic with low body mass index (BMI), the proportion of these individuals recognized by clinicians as malnourished, and what patients' characteristics and caregivers' and clinicians' impressions are associated with low BMI.

DESIGN

Cross-sectional study.

SETTING

An outpatient geriatric clinic located in a university-affiliated teaching hospital.

PARTICIPANTS

340 patients with Alzheimer's disease, average age 75 years.

MEASUREMENTS

Individuals with a BMI below 21 were considered at risk of malnutrition. Physical examination and medical information were obtained from patients and caregivers by clinicians using a standardized assessment protocol. Clinicians' impression regarding evidence of malnutrition was obtained.

RESULTS

Forty-six patients (16%) had a BMI below 21. Clinicians reported evidence of potential malnutrition in 11 patients, 8 of whom had a BMI below 21. Using logistic regression, we found that women were five times more likely to have a BMI below 21 than men, and that individuals with low cognition were twice as likely to have a BMI below 21 than individuals with higher cognition.

CONCLUSION

The proportion of patients with Alzheimer's disease with a BMI below 21 is similar to that encountered in the general population aged 65+. However, clinicians have difficulty identifying persons at risk of malnutrition according to BMI status. Women with low cognition were at increased risk of having a low BMI. Improvement in the detection of malnutrition is desirable. Further exploration of causal links between cognition and malnutrition is required.

Development of delirium: a prospective cohort study in a community hospital

BACKGROUND

Previous research on risk of delirium in acute hospital settings identified mainly patient variables (e.g., age) that are not amenable to intervention. The purpose of this study was to develop a model for new delirium in hospitalized older patients that included process of care and social variables.

METHODS

A prospective cohort study was undertaken in a community hospital in Ontario, Canada. Research participants included 156 hospitalized patients age 65+ years and without delirium on admission who were admitted to a medical or surgical unit. The measures included daily appraisal of delirium using a standardized and validated tool, and assessment of patient, process of care, and social variables.

RESULTS

Delirium developed in 28 of the 156 patients (17.9%). Older age and cognitive impairment were significant patient variables. Significant process of care variables included a high number of medications administered during hospitalization, surgery, a high number of procedures during early hospitalization (e.g., x-rays, blood tests), and intensive care treatment.

CONCLUSIONS

Approximately one older patient in five developed delirium after admission to a medical or surgical unit. Risks not easily amenable to intervention included age, cognitive dysfunction, surgery, and intensive care requirements. Risk factors that are potentially modifiable included number of medications and number of procedures. Future research might focus on the efficacy of such intervention to reduce new-onset delirium in acute hospital settings.

Women's decisions about hormone replacement therapy after education and bone densitometry

BACKGROUND

The decisions that postmenopausal women make about whether to start hormone replacement therapy may depend on the potential risks and benefits of such therapy as well as their risk for osteoporosis-related fractures. This study examined the decisions made by women at risk for osteoporosis-related fractures who were educated about hormone replacement therapy and who were given information about their bone mineral density.

METHODS

The study employed a prospective cohort design. Thirty-seven post--menopausal women with risk factors for osteoporosis-related fractures were recruited from an orthopedic clinic at a teaching hospital in Hamilton, Ont. The women were given an education kit (consisting of an audio tape and a work-book) to clarify the benefits and risks of hormone replacement therapy. Two to 4 weeks later, densitometry of the hip and the lumbar spine was performed. A summary of the risks, the densitometry findings and decisions about hormone replacement therapy were given to the women's family physicians for follow-up. Outcome measures included decisions about hormone replacement therapy, as well as use of such therapy and other medications at 12 months.

RESULTS

After the education component alone, 10 (27%) of the women requested hormone replacement therapy. After densitometry testing, 4 more requested hormone replacement therapy (for a total of 14 women [38%]). At 12 months, 2 (5%) of the women had been lost to follow-up. Of the remaining 35, 6 (17%) were receiving hormone replacement therapy, 7 (20%) were using bisphosphonates, and 24 (68%) were taking calcium supplements.

INTERPRETATION

These preliminary findings suggest that the combination of education about hormone therapy and feedback about bone density is associated with an increase in the use of hormone replacement therapy and other preventive medications by women at risk for osteoporosis-related fractures. However, the observed increase was small and so the clinical significance must be confirmed and clarified.

Factors associated with motor vehicle crashes in cognitively impaired older adults

Because cognitive impairment might pose a safety risk for these drivers and the public, we examined what patient characteristics might be associated with motor vehicle crashes, in a retrospective study of all new referrals to a geriatric clinic specializing in memory and behavior problems between July 1, 1990 and June 30, 1995. During this time, 989 new patients were evaluated by the clinic staff. Driving data were available from 634 patients. The only factor significantly associated with crashes was driving alone (odds ratio = 2.23, 95% confidence interval = 1.20-4.15). Twenty-five percent of patients who drove alone had caregiver-reported crashes in the previous 5 years, compared with 13% of those who drove only with a passenger. Patients who drove alone were more likely to have spousal caregivers than patients who drove only with a passenger (72% vs. 58%, p = 0.028). Thus, cognitively impaired patients allowed to drive alone were more likely to have been involved in crashes than patients not driving alone. However, the causal nature of this association cannot be established with the present design. Prospective studies are required to determine if the presence of a co-pilot represents a safe strategy to extend driving privileges in cognitively impaired older drivers.

Provisional educational needs of health care providers in palliative care in three nursing homes in Ontario

Health care providers in three nursing homes in Ontario were surveyed to determine educational needs, barriers to meeting these needs, and the preferred format for education. Of the 415 health care providers asked to participate, 225 completed the questionnaire. Need was expressed for the majority of the 35 educational topics identified, including the role of the palliative care team, management of physical symptoms, pharmacological and non-pharmacological management of pain, stress management, spiritual needs, culture and death, and counseling. Group discussions and seminars were favored over traditional lectures. The primary factors influencing attendance at a palliative care workshop were loss of pay and time and location of the workshop.

1997 IPA/Bayer Research Awards in Psychogeriatrics. Associations between dysfunctional behaviors, gender, and burden in spousal caregivers of cognitively impaired older adults

Reductions in healthcare spending and current demographic trends will result in increasing demands to care for aging relatives, especially those with cognitive impairment (e.g., Alzheimer's disease). Taking care of older individuals with cognitive impairment can be very challenging and burdensome. Caregiver burden is associated with negative outcomes such as caregiver depression and increased likelihood of patient institutionalization. One hundred eleven patients and their spousal caregivers were studied using a pre-post design. All subjects received a comprehensive medical intervention that included medical management of patients' problems and education of caregivers. We examined changes in patients' function and caregiver burden. At follow-up, patients' cognition and independence in activities of daily living had continued to deteriorate whereas their mood was improved. Regression analyses showed that changes in caregiver burden were positively associated with changes in the frequency of dysfunctional behaviors but not with changes in cognition. Gender was also related to changes in caregiver burden; male caregivers were more likely than female caregivers to report reductions in burden at follow-up. These data suggest medical interventions may provide some relief to caregivers of cognitively impaired older patients, but more research is required to identify the causal agents of this effect.

Measuring capacity to complete an advance directive

OBJECTIVE

To validate reference standards for the assessment of capacity to complete an advance directive and to develop and test three simple screening instruments.

METHODS

We administered five measures of capacity to 96 older subjects from nursing homes, retirement homes, and homes for the aged. The measures included two reference standard evaluations: an assessment by a specially trained nurse in collaboration with a multidisciplinary team (Competency Clinic assessment) and geriatrician assessment using a decisional aid. Three screening instruments were also included: a Generic Instrument designed for any advance directive, a Specific Instrument designed for the "Let Me Decide" advance directive, and the Standardized Mini-Mental Status Examination (SMMSE). The screening instruments and the geriatrician's assessment were administered twice to half of the respondents to determine interrater agreement.

RESULTS

The chance-corrected agreement for the assessment by two geriatricians was 0.78, and for agreement between the geriatricians and Competency Clinic assessments it was 0.82. Agreement for the Generic and Specific screening instrument assessments by two observers was 0.77 and 0.90, respectively. The areas under the Receiver Operating Characteristic curve relating the results of the three screening instruments to the Competency Clinic assessment were 0.82 for the Generic Instrument, 0.90 for the Specific Instrument, and 0.94 for the SMMSE; chance is an unlikely explanation for the difference between these three values (P < or = .01).

CONCLUSIONS

Using rigorous methods, health workers can make reproducible and valid assessments of capacity to complete an advance directive. The SMMSE accurately differentiates people who can learn about and ultimately complete advance directives from those who cannot.

Improved reliability of the Standardized Alzheimer's Disease Assessment Scale (SADAS) compared with the Alzheimer's Disease Assessment Scale (ADAS)

OBJECTIVES

To compare the interrater and intrarater reliability of the Alzheimer's Disease Assessment Scale (ADAS) with the Standardized Alzheimer's Disease Assessment Scale (SADAS).

DESIGN

A randomized, double blind trial. Sixteen university students were randomized to administer either version of the instrument. Subjects were randomized to three assessments, at 2-week intervals, using the ADAS or the SADAS. Each subject's first and third tests were administered by the same rater, the second by a different rater.

SETTING

A geriatric outpatient clinic in a university teaching hospital.

PARTICIPANTS

Fifty-four patients with possible or probable Alzheimer's disease living in the community or in a long-term care facility.

MEASUREMENTS

The primary outcome was the interrater reliability of total ADAS and SADAS scores. Secondary outcomes were ADAS and SADAS cognitive scores, noncognitive scores, duration of testing, and sample size estimates.

RESULTS

The interrater reliability of the SADAS total score was significantly better than that of the ADAS (interrater ICC 0.93 SADAS vs 0.83 ADAS), and the interrater standard deviation of the total SADAS score was lower than that of the ADAS (38%, P < .05). The SADAS cognitive subscale inter and intrarater reliability, although higher than the ADAS, was not significantly different when used by different raters (interrater ICC 0.91 SADAS vs 0.90 ADAS; intrarater ICC 0.88 SADAS vs 0.86 ADAS). The SADAS noncognitive subscale was significantly more reliable than the ADAS (interrater ICC 0.89 SADAS vs 0.42 ADAS; intrarater ICC 0.87 SADAS vs 0.70 ADAS; P < or = .05) and had a lower standard deviation between raters (59%; P < .01) and within raters (40%; P < .05) compared with the ADAS.

CONCLUSION

The improved reliability of the SADAS total score means that investigators can now use this score as a primary outcome measure, and important behavioral symptomatology can be included as a marker for treatment efficacy in AD. The smaller standard deviation of the SADAS means that clinical trials using the SADAS as a primary outcome will demonstrate differences, if present, with smaller sample sizes than with the ADAS.

Dysfunctional Behavior Rating Instrument

A dysfunctional behavior can be defined as “an inappropriate action or response, other than an activity of daily living, in a given social milieu that is a problem for the caregiver.” Dysfunctional behaviors commonly accompany cognitive impairment and are a significant source of burden to caregivers. Dysfunctional behaviors may be the first sign of a dementing illness, even before caregivers perceive changes in the patient's cognitive abilities. However, unlike cognitive impairment, dysfunctional behaviors are amenable to medical treatment. Effective treatment of these behaviors requires their description and identification, evaluation of their frequency and impact on the caregiver, identification of causes, development of a treatment plan, and evaluation of the effects of treatment.

Clinical trials in cognitively impaired older adults: home versus clinic assessments

OBJECTIVE

To compare the reliability of instruments used in clinical trials involving cognitively impaired older adults when the instruments are administered in-home rather than in-clinic and to compare withdrawal rates is these two groups.

DESIGN

This study was part of a larger n-of-1 clinical trial to investigate the efficacy and safety of a MAO/A inhibitor (Brofaromine) in patients with Alzheimer's disease. Participants were initially assessed at the clinic (baseline) and then randomly allocated to in-home or in-clinic assessments for the remainder of the trial. The baseline and second assessment (performed before initiation of the treatment) were used for the reliability analysis. Withdrawal rates were examined over the course of the 6-month trial.

SETTING

Assessments took place at a geriatric clinic in an urban university teaching hospital and at residences of some of the patients.

PARTICIPANTS

Forty-six Alzheimer's disease patients participated in the study, of which, 22 were randomized to in-home assessments and 24 to in-clinic assessments.

MEASUREMENTS

Test-retest reliability was measured for all five instruments used in the study and was based on the first two assessments. Sample size requirements, based on within-group variance, were calculated. Withdrawal rates were obtained for the total duration of the trial.

RESULTS

Test-retest reliability of the instruments, as determined by intraclass correlations, was good in both groups but favored in-clinic for all but one instrument (range: 0.47-0.90 for in-home vs 0.57-0.92 for in-clinic). Sample size requirements based on reliability assessment data were found to be larger for some instruments when administered in-home. Only four in-home patients withdrew before completion of the study, compared with eight in-clinic patients.

CONCLUSION

The results suggest the in-home assessments in cognitively impaired older adults may result in lower withdrawal rates but may necessitate larger sample sizes to offset larger test-retest variability.