Reliability of a medication adherence measure in an outpatient setting

BACKGROUND

Reliable approaches for measuring antihypertensive medication compliance in the outpatient setting are not readily available. The objective of the current study was to determine the reliability of the Hill-Bone Compliance Scale among elderly hypertensive patients.

METHODS

We conducted a cross-sectional survey of community-dwelling patients attending the hypertension section of the Internal Medicine Clinic in a large multispecialty group practice. Participants (n=239) completed a self-administered questionnaire consisting of demographic questions and the Hill-Bone Compliance to High Blood Pressure Therapy Scale, which includes a nine-item medication compliance subscale.

RESULTS

The mean age of respondents was 69 years; 51% of patients were men, 73% were white, 86% had at least a high school education, and 61% were married. The Cronbach alpha was 0.68 for the medication compliance subscale. All nine items of the medication compliance subscale maintained higher correlations with their own subscale total than with the salt intake and appointment keeping subscale totals. After adjusting for other demographic variables, the odds ratio (95% confidence interval) of perfect medication compliance as reported on the medication compliance subscale was 1.71 (0.95-3.07) for participants 65 years of age and older versus those younger than 65 years of age, 2.53 (1.37-4.66) for whites versus nonwhites, 1.27 (0.73-2.20) for males versus females, 1.30 (0.73-2.29) for married versus unmarried participants, and 1.63 (0.74-3.62) for those with at least a high school education versus those with less education.

CONCLUSION

The medication compliance subscale of the Hill-Bone Compliance Scale appears reliable and may be a useful tool for detecting noncompliant patients in outpatient settings.

The intracrine hypothesis: an update

The intracellular actions of peptide hormones, growth factors, as well as of extracellular-signaling enzymes and DNA-binding proteins, either within target cells or within their cells of synthesis has been called intracrine action. Although these intracrine moieties are structurally diverse, they share certain characteristics of synthesis and function. This has given rise to the development of a theory of intracrine action which permits testable predictions to be made regarding the functioning of these peptides/proteins. Here the intracrine hypothesis is briefly described and then recent experimental findings which bear on predictions made earlier on the basis of the theory are discussed. These findings provide new support for the intracrine hypothesis.

Mechanisms of Disease: local renin–angiotensin–aldosterone systems and the pathogenesis and treatment of cardiovascular disease

Accumulating evidence has made it clear that not only does the renin-angiotensin-aldosterone system (RAAS) exist in the circulation where it is driven by renal renin, but it is also active in many tissues-and likely within cells as well. These systems might not be completely independent of each other, but rather interact. These local RAASs affect tissue and cellular angiotensin II concentrations and appear to be associated with clinically relevant physiologic and pathophysiologic actions in the cardiovascular system and elsewhere. Evidence in support of this possibility is reviewed here. In addition, direct (pro)renin action after binding to its specific receptor, the existence of renin transcripts, which apparently encode an intracellular renin, the discovery of an angiotensin-converting-enzyme homologue (ACE2), which leads to enhanced generation of angiotensin-(1-7) and the newly appreciated role of angiotensin-receptor dimerization in the regulation of angiotensin activity, all point to the conclusion that the RAASs are complexly regulated, multifunctional systems with important roles both within and outside the cardiovascular system.

The inhibition of tumor growth by triplex-forming oligonucleotides

We have previously shown that oligonucleotides designed to bind in triplex fashion to a specific p53 binding site homology inhibit the proliferation of colon cancer cells in vitro. The present study was designed to extend these observations in an in vivo model. HCT 116 human colon carcinoma cells were injected subcutaneously into Ncr nude mice and tumors formed at one to two weeks. Tumors were injected daily for 14 days with either triplex forming oligonucleotide (Hoog 1), a scrambled Hoog 1 oligonucleotide (Hoog3) as control, or vehicle. Tumor size was measured twice weekly. Active triplex forming oligonucleotide (Hoog1) reduced tumor size in comparison to either control oligonucleotide (Hoog3) or vehicle. Tumor sizes in the three groups were significantly different (P < 0.001). Student Newman Keuls test shows statistically significant differences between the experimental group and each of the control and vehicle groups (P < 0.05). A triplex forming oligonucleotide directed at a p53 consensus binding site reduces tumor growth suggesting a novel method of tumor inhibition.

A proposal regarding the biology of memory: participation of intracrine peptide networks

Although progress has recently been made in defining its neurobiological underpinnings, memory remains an incompletely understood process. Here it is proposed that intracrine peptide action plays a role in memory and therefore in consciousness. Intracrine function is the intracellular action of a peptide either in its cell of synthesis or in target cells following internalization. Intracrine functionality has been associated with growth factors, transcription factors, and enzymes. Some intracrines have been shown to modify their own synthesis, the synthesis of components of their signaling cascades, and/or the synthesis of other intracrines, making it likely that these factors participate in peptinergic regulatory loops/networks. Moreover, some intracrines can affect cellular ion flows over short time periods, while stimulating protein synthesis and growth over longer periods. Intracrines have been reported in the brain (for example, angiotensin, brain derived neurotrophic factor, reelin, and fibroblast growth factor 2) and it is here suggested that intracrine expression/action occurs commonly in the nervous system and, in particular, in the cerebral cortex. This intracrine action leads to the formation of long-lived intra- and intercellular intracrine feed back loops. The intracrine networks thus formed participate in producing both short and long term synaptic potentiation; the former effect is primarily related to intracrine effects on ion flows, the latter to intracrine directed protein synthesis. In addition, intracrine networks provide a previously unappreciated dynamic substrate for the integration of information and ultimately for the formation of the associations that underlay consciousness.

Tissue renin angiotensin systems

The RAAS is a powerful regulator of vascular tone and intravascular volume and of tissue architecture and a variety of other functions. The recent appreciation of the immunoregulatory role of angiotensin II and its possible involvement in the genesis of atherosclerosis and in plaque rupture all speak to the wide-ranging physiologic and pathophysiologic activities of the peptide. So do its actions in fat cell differentiation and in neuromodulation. The system exists in the circulation, and RAASs, whole or partial, exist in many tissues. These systems are regulated at many levels ranging from the synthesis of renin to the dimerization of angiotensin receptors. Regulation occurs in multiple tissues and, as a result, tissue concentrations of angiotensin II and the concentration of other RAS components and their active metabolites can vary independently of the circulating system in these tissues. An RAS seems also to function within certain cells. Therapeutic interventions involving ACEIs and ARBs seem likely to provide benefit at least in part through the interruption of local systems. It is to be expected that with enhanced understanding of the biology of the multiple RASs, new suggestions for therapeutic interventions will be forthcoming.

Accuracy of Telemedicine in Detecting Uncontrolled Hypertension and Its Impact on Patient Management

This study was aimed at assessing the diagnostic accuracy of telemedicine among hypertensive patients. This was a cross-sectional analysis of patients attending a hypertension clinic over a year-long study. Patients were seen both by telemedicine and in-person on the same day with order of the encounters randomly determined. A telemedicine system, which utilized phone lines, was employed. For each type of encounter, whether telemedicine (TM) or in-person (IP), clinical data on blood pressure (BP) control as well as physician ordering patterns were collected. Receiver Operator Characteristic (ROC) curves were used to assess the validity of TM as compared to IP in the assessment of uncontrolled hypertension. Sixty-two patients participated resulting in 107-paired visits over the year-long study period. The mean age of the 62 participants was 67.1 +/- 11.4 years; 56.6% were men. ROC curves for detecting elevated mean blood pressure provided an area under the curve (auc) of 0.87 (95% CI, 0.80-0.95). ROC curves for the detection of uncontrolled systolic hypertension provided an auc of 0.86 (95% CI, 0.78-0.93). Telemedicine-determined BP differed slightly, but statistically significant (p < 0.05), from IP assessments. Meanwhile, there was no difference in ordering diagnostic tests or therapeutics detectable between the two encounter types. Telemedicine proved to be a valid means for detecting uncontrolled BP among hypertensive patients.

Intracellular renin and the nature of intracrine enzymes

Recently, the binding of renin and prorenin to cellular receptors with the subsequent generation of second messengers and the production of physiological effects has been demonstrated. In addition, the internalization of prorenin by target cells has been associated with increased cellular synthesis of angiotensin and cardiac pathology. Also, a renin transcript lacking the sequences encoding a secretory signal has been reported, and this transcript appears to produce a renin that acts in the cell that synthesized it. Some years ago, we coined the term intracrine for a peptide hormone or factor that acts in the intracellular space either after internalization or retention in its cell of synthesis. Thus defined, a wide variety of peptides display intracrine functionality, including hormones, growth factors, transcription factors, and enzymes. For example, considerable evidence indicates that angiotensin II is an intracrine. Also, general principles of intracrine functionality have been developed. Thus, recent evidence demonstrates that the prorenin/renin molecule is an intracrine enzyme. Here, the actions of intracrine enzymes (angiogenin, phosphoglucose isomerase, phospholipase A2, granzyme A and B, thioredoxin, platelet-derived endothelial growth factor, and serine protease inhibitors) are reviewed. The relation of prorenin/renin to other intracrine enzymes, and to intracrines in general, is discussed.

Application of the combined quality improvement ratio in the evaluation of a quality improvement activity in a managed care organization

Assessing the impact of clinically relevant quality improvement activities (QIA) is important to managed care organizations; yet, turnover in enrollment can reduce the data available for analyses, thus decreasing the chance that a difference post-QIA will be detected. The Combined Quality Improvement Ratio (CQuIR) uses matching of patients into pairs pre- and post-QIA to systematically and validly increase the data included in the analysis for evaluation of the QIA. Using a paired cohort study design, 456 pairs of patients with diabetes were identified using the Health Plan Employer Data Information Set (HEDIS) specifications. Patients having retinal examinations were identified pre- and post-QIA. The change in retinal examination rates was analyzed and results compared using repeated pairs (RP), matched pairs (MP), and combined pairs (CP). The CQuIR methodology (which uses CP = RP + MP) resulted in an increase in sample size (n = 456 [CP] versus n = 156 [RP] and n = 300 [MP]) and consequently an increase in power (0.92 [CP] versus 0.38 [RP] and 0.82 [MP]) and a decrease in the confidence interval range (0.97 [CP] versus 2.06 [RP] and 1.14 [MP]). The CQuIR uses a statistically valid approach to increase the data available for the evaluation of QIAs.

The intracrine hypothesis and intracellular peptide hormone action

There is evidence that many peptide growth factors and hormones act in the intracellular space after either internalization or retention in their cells of synthesis. These factors, commonly called intracrines, are structurally diverse while sharing some common functional features. Reports of intracellular peptide hormone binding and action are reviewed here. Also, this laboratory has made proposals regarding the origin and actions of intracrines and these areas are further explored. Intracrine interactions and the relationship of intracrines to transcription factors are discussed. The intracellular/intracrine renin-angiotensin system (iRAS) is reviewed to illustrate the intracrine analogue of a well-established physiological system. The role of intracrine action in metazoan development is also considered.

Intracellular angiotensin II increases the long isoform of PDGF mRNA in rat hepatoma cells

Our recent published studies suggest that angiotensin II (AII), generated and retained intracellularly, enhances growth of H4-II-E-C3 rat hepatoma cells, an average of 33%. Proliferation conferred by introduction of a plasmid [ Ang(-S)Exp/pSVL ] encoding a signal sequence-depleted angiotensinogen [Ang(-S)Exp] into these cells (which we have shown possess ACE and renin mRNAs) is mediated, at least in part, by enhanced PDGF-A chain mRNA production and protein secretion. The mitogenic effect is inhibited by losartan suggesting that it involves AII interaction with an AT(1)-like receptor. Introduction of anti-AII antibodies into the medium of these transfected cells has no effect upon growth of the cells, suggesting that AII is retained by the cells and that intracellular AII is growth stimulatory. In the present study, we sought to further characterize the intracellular localization and mode of action of Ang(-S)Exp. Consistent with our expectations, we now show that a fusion product of Ang(-S)Exp with green fluorescent protein [Ang(-S)Exp/EGFP], generated from an expression plasmid, is abundant and primarily cytoplasmic. Wild-type angiotensinogen/EGFP, in contrast, is only detectable following a cold-block (which acts to enhance folding-kinetics and slow secretion) and is largely restricted to the secretory pathway. We further show, using semi-quantitative RT/PCR that the long isoform of PDGF mRNA is elevated in Ang(-S)Exp transfected cells and in AII-treated naive cells but not in losartan-treated Ang(-S)Exp transfected cells. We identify C-terminal amidation recognition sites within the long-form protein (that are not present in the short-form) and show that these cells possess PAM (amidating enzyme precursor) and carboxypeptidase E mRNAs (the corresponding proteins of which are sufficient for amidation). Inhibitors of amidation inhibit growth of naive and Ang(-S)Cntr/ pSVL -transfected cells (2.6-fold for phenylbutenoic acid and 3.5-fold for disulfiram treatment) but more profoundly inhibit growth of Ang(-S)Exp/pSVL -transfected cells (6.7-fold for phenylbutenoic acid and 13-fold for disulfiram). In conclusion, these data confirm that signal sequence-depleted Ang(-S)Exp is retained within cells and is largely cytoplasmic. Because C-terminal amidation is absolutely required for full biological potency of a number of peptide hormones (including oxytocin, gastrin and calcitonin), we postulate that growth effects of both intracellular AII and exogenous AII can be conferred by PDGF long-form, possibly through an amidation-dependent mechanism.

Toward a theory of intracrine hormone action

A growing body of evidence indicates that in some cases, peptide hormones can function in the intracellular space. These findings are reviewed. In addition, this laboratory has made proposals regarding the origin, nature and function of intracrines--that is, intracellularly acting peptide hormones that also function in an autocrine, paracrine or endocrine manner. Here, these hypotheses are developed, and potential implications/applications of this point of view are discussed. Possible implications for cellular differentiation, cellular memory and hormonal responsiveness, as well as for the assumption of novel functions by intracellular regulatory proteins are discussed.

The effect of education on patients' willingness to participate in a telemedicine study

We assessed the effect of previous education on patients' willingness to participate in a clinical study of telemedicine for hypertensive patients. The design was a cross-sectional study of adult patients arriving for appointments in a hypertension clinic. Of the 259 patients approached, 86% completed a baseline survey and were subsequently asked if they would be willing to participate in a one-year telemedicine study. One hundred and fifty patients (58%) agreed to participate. A stepwise logistic regression analysis was performed to assess the effect of level of education on willingness to participate, while controlling for potentially confounding variables. In the final model, only education remained significant. The odds ratio for non-participation of patients with high-school education or less was 3.6 (95% confidence interval 1.9-7.0). Educational status should be carefully considered when designing, implementing and interpreting telemedicine studies.

The origins of intracrine hormone action

A growing number of peptide hormones and growth factors have been shown to operate in the intracellular space after either internalization or retention in their cells of synthesis. These factors, called intracrines, in many cases are expressed as multiple isoforms, traffic to nucleus or nucleolus, and regulate gene transcription. Some intracrines are angiogenic. It is here argued that intracrine action is the modern analogue of a biologically ancient mechanism for regulating message translation and ribosome synthesis. The implications of this view for research and therapeutics are discussed.

In vitro evidence for an intracellular site of angiotensin action

To differentiate the relative effects of nuclear and cell surface angiotensin II (Ang II) receptors, we mutated the angiotensinogen cDNA by removing the signal sequence-encoding region to produce a nonsecreted form of angiotensinogen [Ang(-S)Exp]. Rat hepatoma cells (which produce renin and angiotensin-converting enzyme mRNAs) were stably transfected with Ang(-S)Exp/pSVL (or a corresponding control) expression plasmid, and mitotic indices were measured for stably transfected cell lines. Experimental clonal cell lines demonstrate an average of 33+/-4.4% (P<0.001) increase in percentage-labeled nuclei compared with control cell lines. The mitogenic effect is blocked by 10(-6) mol/L losartan and by 1 micromol/L renin antisense phosphorothioate oligomers but not by 10(-6) mol/L candesartan. In addition, phenylarsine oxide, which blocks angiotensin receptor internalization, abolishes the losartan inhibitory effect, suggesting that after cell-surface receptor-mediated endocytosis, losartan blocks Ang II nuclear receptors. PDGF mRNA levels are elevated 2.2-fold in Ang(-S)Exp transfected cell lines; addition of anti-PDGF antibodies to the culture medium partially blocks the mitogenic effect of Ang(-S)Exp, while anti-Ang II antibodies have no effect. These results suggest that the Ang(-S)Exp growth effect is due, in part, to autocrine/paracrine stimulation by secreted PDGF after Ang II/Ang II receptor intracellular interactions. We further demonstrate that these cells produce the alternative renin transcript, renin 1A, which apparently lacks a signal sequence and is maintained intracellularly. Collectively, these studies of cultured cells suggest that some cell types may possess components of the renin-angiotensin system that permit intracellular processing of angiotensinogen to Ang II and that Ang II generated intracellularly may be mitogenic.

The clinical implication of tissue renin angiotensin systems

The presence, and in many cases the regulated synthesis, of components of the renin-angiotensin system have been demonstrated in multiple tissues, indicating the existence of tissue angiotensin-generating systems. These vary with respect to which renin-angiotensin system components are synthesized locally and which are taken up from plasma. Enzymes unrelated to the classical renin-angiotensin system may also contribute to tissue angiotensin synthesis. However, based on the available data, the prevailing opinion that kidney-derived renin is in all cases the only physiologically relevant renin in tissues must be revised. Also there is evidence indicating a role for tissue angiotensin systems in the pathogenesis of cardiovascular disease and in cardiovascular structural remodeling. The angiotensin-regulated synthesis of aldosterone in cardiac tissue has been described, suggesting the possibility that a renin-angiotensin-aldosterone system exists in the heart. In addition, intracellular (intracrine) sites of angiotensin action have been reported. Some of these findings have implications for therapeutics and, in particular, for the use of angiotensin converting-enzyme inhibitors and angiotensin receptor blockers. Finally, tissue angiotensin systems outside the cardiovascular system also appear to be physiologically relevant.

Patient and physician satisfaction in a clinical study of telemedicine in a hypertensive patient population

We studied patient and physician satisfaction with telemedicine for the care of a hypertensive population. Once recruited, participants were seen both in person and via telemedicine (in random order) on the same day. After each meeting, patient and physician satisfaction surveys were completed. In the 12-month study, there were 107 pairs of visits. The physicians reported a small but significant increase in workload, mental effort, technical skills and visit duration for telemedicine when compared with face-to-face consultations. They noted that the telemedicine system worked well in the majority of cases and could reduce the need for future treatment. Patients reported slightly but significantly higher satisfaction scores for the following for in-person than for telemedicine meetings: technical quality, interpersonal care and time spent. Patients reported high satisfaction scores for both telemedicine and in-person visits.

A method to report utilization for quality initiatives in medical facilities

OBJECTIVE

We undertook this project to outline a methodology for quantifying aggregate health care utilization of medical "technologies" that could be rank ordered by volume. The identification of specific high-volume technologies could guide future efforts for quality initiatives such as program planning, preventive services implementation, quality improvement activities, and innovative and cost-effective technology development.

DESIGN

This study utilized a retrospective cross-sectional study design.

METHODS

We generated combined ranks for the top 200 high-volume procedures from three data sources that incorporated in- and outpatient procedures. Data were collected using primarily ICD-9 and CPT-4 codes; all codes were translated into CPT-4 codes and collapsed into categories using truncated three-digit CPT-4 codes. Frequencies for each collapsed code were determined with each dataset; procedures were reranked based on the mean rank of the three sources.

MAIN OUTCOME MEASURES

We itemized the individual procedure codes making up each of the top 20 categories and reported the unique codes making up at least 80% of the procedure code category.

RESULTS

The top five procedure categories identified in this study were patient visits (inpatient and outpatient), chest x-rays, mammograms, ophthalmological services, and electrocardiograms.

CONCLUSION

The methodology described provides a new way to combine and concisely report on utilization of procedures that is relevant to data obtained from different sources. This methodology may be of potential benefit to health care administrators, technology developers, and other planners as they contemplate ways to identify quality and technology development initiatives that can have a broad impact on populations served by health care organizations.

Testing efficacy with detection controlled estimation: an application to telemedicine

Detection controlled estimation (DCE) is a powerful new econometric estimator in the family of missing data estimators. By collecting measures from a variety of inspectors or inspection technologies, DCE is able to make inferences about the entire population, even when that population is not directly observed. Using this innovative method, we were able to assess whether telemedicine technology could be substituted for in-person visits when providing maintenance care for patients with hypertension. Our findings indicate that there is no support for the proposition that telemedicine is less effective than in-person visits for determining whether patients have high blood pressure. Indeed, our results imply that telemedicine misses 7% fewer cases of high blood pressure than in-person visits do. The results of this study indicate that DCE may be an effective tool for use in cost-effectiveness or cost-benefit analysis in health care.