White coat effect: semantics, assessment and pathophysiological implications

The Quest for Ecological Validity in Hearing Science: What It Is, Why It Matters, and How to Advance It

Ecological validity is a relatively new concept in hearing science. It has been cited as relevant with increasing frequency in publications over the past 20 years, but without any formal conceptual basis or clear motive. The sixth Eriksholm Workshop was convened to develop a deeper understanding of the concept for the purpose of applying it in hearing research in a consistent and productive manner. Inspired by relevant debate within the field of psychology, and taking into account the World Health Organization's International Classification of Functioning, Disability, and Health framework, the attendees at the workshop reached a consensus on the following definition: "In hearing science, ecological validity refers to the degree to which research findings reflect real-life hearing-related function, activity, or participation." Four broad purposes for striving for greater ecological validity in hearing research were determined: A (Understanding) better understanding the role of hearing in everyday life; B (Development) supporting the development of improved procedures and interventions; C (Assessment) facilitating improved methods for assessing and predicting ability to accomplish real-world tasks; and D (Integration and Individualization) enabling more integrated and individualized care. Discussions considered the effects of variables and phenomena commonly present in hearing-related research on the level of ecological validity of outcomes, supported by examples from a few selected outcome domains and for different types of studies. Illustrated with examples, potential strategies were offered for promoting a high level of ecological validity in a study and for how to evaluate the level of ecological validity of a study. Areas in particular that could benefit from more research to advance ecological validity in hearing science include: (1) understanding the processes of hearing and communication in everyday listening situations, and specifically the factors that make listening difficult in everyday situations; (2) developing new test paradigms that include more than one person (e.g., to encompass the interactive nature of everyday communication) and that are integrative of other factors that interact with hearing in real-life function; (3) integrating new and emerging technologies (e.g., virtual reality) with established test methods; and (4) identifying the key variables and phenomena affecting the level of ecological validity to develop verifiable ways to increase ecological validity and derive a set of benchmarks to strive for.

A comparison of first trimester blood pressures obtained at the time of first trimester pre-eclampsia screening and those obtained during prenatal care visits

OBJECTIVE

To determine if enrollment blood pressures in a study on first trimester preeclampsia prediction significantly differed from those obtained during routine prenatal care visits in the first trimester.

STUDY DESIGN

Women carrying a singleton gestation were prospectively enrolled in a first trimester study on preeclampsia prediction, and had systolic and diastolic blood pressure (SBP, DBP) measured at the time of enrollment. Blood pressure was also measured with the same technique by clinic nurses during the routine prenatal visits throughout the first trimester of pregnancy (9-14 weeks). The enrollment-BP (E-BP) and average first trimester-BP (aFT-BP) were compared using a paired samples t-test or Wilcoxon test, as appropriate. Smokers and patients on antihypertensive medications were excluded from the analysis. test.

RESULTS

644 women had prenatal care in the primary study center and met study criteria. The mean gestational age at study enrollment was 12.5 weeks. No significant difference was found between E-SBP and aFT-SBP (p = 0.10). Enrollment DBP and mean arterial pressure (MAP) were significantly lower than the aFT- DBP and -MAP (median DPB 67 vs 70 mm Hg and median MAP 83.7 vs 85 mmHg, respectively, p < 0.001). However, the difference was not clinically relevant (3 mmHg for DBP, and 1.3 mmHg for MAP).

CONCLUSIONS

Blood pressures obtained in a setting of preeclampsia screening are not higher than those obtained during regular prenatal care in the first trimester. This suggests that the setting in which pre-eclampsia screening is performed is unlikely to be a confounder for blood pressure measurements and the risk assessment.

Long term outcomes of cluster randomized trial to improve cardiovascular health at population level: The Cardiovascular Health Awareness Program (CHAP)

Study question

The Cardiovascular Health Awareness Program (CHAP) cardiovascular risk reduction program consisted of sessions run by local volunteers in local pharmacies during which cardiovascular risk was assessed, healthy lifestyle and preventive care was promoted, and the participants were oriented to local resources to support changes in modifiable risk factors. A clustered randomized trial implemented in September 2006 across 39 communities targeting community-dwelling individuals 65 years and older showed a significant reduction in hospitalization one year after its implementation (rate ratio of 91 [95% confidence interval (CI): 86%-97%]). This study explores the impact of CHAP in the first five years.

Methods

Using health administrative data housed at the Institute for Clinical Evaluative Sciences, we established a closed cohort consisting of all individuals eligible in these communities at the study onset whom we followed over time. We assessed hospitalizations and survival using a negative binomial model for count data and Cox regression to assess time to first event, accounting for the clustered design. The primary outcome was the rate of cardiovascular-related hospitalizations defined as congestive heart failure, stroke or acute myocardial infarction.

Results

Most estimates pointed to an advantage for the intervention arm, but only all-cause mortality reached statistical significance (hazard ratio [95% CI] = 0.955 [0.914–0.999]). The hospitalization cardiovascular-related hospitalization rate ratio was (0.958, 95% CI: 0.898–1.022) in favour of the intervention communities, translating to an estimated 408 averted hospitalizations over the five-year period. There was no evidence of the effect of time from start of intervention.

Conclusions

The consistent direction of the outcomes in favour of the intervention arms suggests that CHAP likely had a meaningful impact on reducing cardiovascular-related morbidity and mortality. Given the low cost of the intervention, further development of CHAP should be pursued.

The impact of a cardiovascular health awareness program (CHAP) on reducing blood pressure: a prospective cohort study

Background

Hypertension is an important and modifiable cardiovascular risk factor that remains under-detected and under-treated, especially in the older individuals. Community-led interventions that integrate primary health care and local resources are promising approaches to improve awareness and management of hypertension and other cardiovascular risk factors. We aimed to evaluate the effect of a community-based Cardiovascular Health Awareness Program (CHAP) on participants’ blood pressure.

Methods

This study followed a cohort of community residents that participated in CHAP across 22 mid-sized Ontario communities over an 18-month period. The participants’ baseline risk factors, including blood pressure, and subsequent measures of blood pressure were recorded. We employed a bivariate linear mixed-effect model to estimate the change of systolic and diastolic blood pressure over time among the participants who attended more than two CHAP sessions.

Results

Of 13,596 participants, 2498 attended more than two CHAP sessions. For those repeated participants (attending more than two sessions) initially identified with high blood pressure, the average reduction of systolic blood pressure was from 142 to 123 mmHg over an 18-month period, a monthly rate ratio of 0.992 (95% CI: 0.991,0.994; p < 0.01). Similarly, the average reduction of diastolic blood pressure was from 78 to 69 mmHg, a monthly rate ratio of 0.993 (95% CI: 0.991,0.994; p < 0.01). The average blood pressure of the participants with normal baseline blood pressure remained controlled and unchanged. We also found that older adult participants who lived alone, were diagnosed with hypertension, reported healthier eating habits, and presented with a higher baseline systolic blood pressure had significantly greater odds of attending more than one session.

Conclusions

CHAP was associated with a reduction in systolic and diastolic blood pressure for those participants who attended more than one session. The magnitude of blood pressure reductions was significant clinically and statistically.

Reproducibility of blood pressure variability, white‐coat effect and dipping pattern in untreated, uncomplicated and newly diagnosed essential hypertension

OBJECTIVE

To investigate the reproducibility of blood pressure (BP) variability, white-coat effect (WCE) and nocturnal dipping pattern in untreated patients with uncomplicated essential hypertension using 24-hour ambulatory BP monitoring (ABPM).

METHODS

Seventy-five newly diagnosed, untreated essential hypertensive subjects (54 men, 21 women 47.6 +/- 9.3 years) were recruited for the study based on conventional measured BP from a total of 180 patients referred for ABPM. Of these, 65 patients underwent repeated ABPM after 4 weeks observation without treatment. Reproducibility of BP, nocturnal dipping pattern, WCE and BP variability were assessed using different methods.

RESULTS

The average 24-hour BP (140.8 +/- 11.9/91.8 +/- 6.4 vs. 140.5 +/- 14.5/90.7 +/- 7.6 mmHg, ns) or PP (49.6 +/- 10.8 vs. 49.8 +/- 9.8 mmHg, ns) did not change, nor did daytime BP or PP. The WCE diminished significantly during the observation period (reduction in SBP WCE delta8.2 +/- 12.5 mmHg, p < 0.0001, in DBP WCE, delta3.3 +/- 9.2 mmHg, p = 0.008 and in PP WCE delta4.8 +/- 11.2 mmHg, p = 0.002). Variability in SBP, DBP and PP decreased consistently and significantly during the observation period. The nocturnal dipping pattern was unchanged in 82% of the patients. In 12% non-dipping pattern was converted to dipping pattern after repeated measurement.

CONCLUSION

Average ABPs are highly reproducible in patients with uncomplicated essential hypertension of limited duration. Similarly, nocturnal dipping pattern reproduced satisfactorily. These measures have important clinical applicability. The white-coat effect as well as variability are greatly attenuated during repeated measurements, and these measures may thus be of less utility in clinical practice.

Cardiovascular Health Awareness Program (CHAP): a community cluster-randomised trial among elderly Canadians

OBJECTIVE

High blood pressure is an important and modifiable cardiovascular disease risk factor that remains under-detected and under-treated. Community-level interventions that address high blood pressure and other modifiable risk factors are a promising strategy to improve cardiovascular health in populations. The present study is a community cluster-randomised trial testing the effectiveness of CHAP (Cardiovascular Health Awareness Program) on the cardiovascular health of older adults.

METHODS

Thirty-nine mid-sized communities in Ontario, Canada were stratified by geographic location and size of the population aged >or=65 years and randomly allocated to receive CHAP or no intervention. In CHAP communities, residents aged >or=65 years were invited to attend cardiovascular risk assessment sessions held in pharmacies over 10 weeks in Fall, 2006. Sessions included blood pressure measurement and feedback to family physicians. Trained volunteers delivered the program with support from pharmacists, community nurses and local organisations.

RESULTS

The primary outcome measure is the relative change in the mean annual rate of hospital admission for acute myocardial infarction, congestive heart failure and stroke (composite end-point) among residents aged >or=65 years in intervention and control communities, using routinely collected, population-based administrative health data.

CONCLUSION

This paper highlights considerations in design, implementation and evaluation of a large-scale, community-wide cardiovascular health promotion initiative.

Automated office and home phone-transmitted blood pressure recordings in uncontrolled hypertension treated with valsartan and hydrochlorothiazide

The study objective was to evaluate, by means of automated office and phone-transmitted home blood pressure (OBP and HBP) recordings, the effects of a fixed combination of valsartan 160 mg and hydrochlorothiazide (HCTZ) 25 mg in hypertensive patients previously uncontrolled with the combination of an angiotensin receptor antagonist and HCTZ. From 241 selected patients, 171 (71%) had uncontrolled hypertension OBP and HBP [mean baseline OBP and HBP systolic and diastolic (SBP/DBP): 157/91 and 152/87 mmHg]. In this open-design study, patients were directly switched from other angiotensin receptor blocker combination products to valsartan/HCTZ for 6 weeks. The same validated automated device was used for OBP and HBP recordings. At baseline, mean HBP was 152 +/- 15/87 +/- 10 mmHg and mean OBP was 157 +/- 12/91 +/- 9 mmHg. After 6 weeks of treatment with valsartan 160 mg and HCTZ 25 mg, a significant decrease in BP was observed both at home (146 +/- 17/83 +/- 12 mmHg) and at the office (151 +/- 18/87 +/- 11 mmHg), with a difference from baseline of -4 mmHg, p < 0.001 for DBP and of -6 mmHg for SBP, p < 0.001. The percentage of patients with office and home control was 24% and 23% respectively, with a kappa index at 0.459. Elevated OBP only (office hypertension) was observed in 3.6% and elevated HBP only (masked hypertension) in 10% of patients. In conclusion, treatment with valsartan and HCTZ 25 mg in patients with confirmed uncontrolled hypertension induced a clinically relevant decrease in BP with approximately 23% of additional patients strictly controlled with a single tablet. The use of an automated oscillometric device at the office and at home allowed the detection of controlled subjects with good agreement.

Influence of the presence of doctors-in-training on the blood pressure of patients: a randomised controlled trial in 22 teaching practices

Until now, no information is available about the effect of the presence of a doctor-in-training on a patient's blood pressure. We tested the hypothesis that the presence of a last year medical student might increase the blood pressure of the patient, in addition to the possible pressor response to the doctor-trainer. Normotensive and hypertensive patients with a minimum age of 25 years, visiting for any reason, were recruited at 22 teaching general practices. Patients were randomised into a 'trainee' group (n=133) and a 'no trainee' (n=129) group. The blood pressure was measured at two subsequent contacts. In the 'trainee' group, a student was present at the first visit only. In the 'no trainee' group, both visits were without student. Both groups had similar anthropometric characteristics at entry. At the first visit, systolic pressure was higher in the 'trainee' group than in the control group (139.5 vs 133.1 mmHg, P=0.004), with a similar trend for diastolic pressure (80.2 vs 77.8 mmHg, P=0.07). From the first contact to the follow-up visit, blood pressure decreased in the trainee group by 4.8 mmHg systolic (P<0.001) and 1.7 mmHg diastolic (P=0.03), whereas the corresponding changes in the control group were -0.1 mmHg (P=0.90) and +1.5 mmHg (P=0.03). Thus, the between group differences in these trends averaging 4.7 mmHg (CI 1.5-7.9, P=0.005) systolic and 3.2 mmHg (CI 1.1-5.3, P=0.003) diastolic were statistically significant. We conclude that in teaching-practices, the presence of a doctor-in-training has a significant pressor effect when an experienced general practitioner measures a patient's blood pressure. If confirmed, our findings imply that doctors should be cautious to initiate or adjust antihypertensive treatment when blood pressure readings are obtained in the presence of a student.

White-coat hypertension: a clinical review

White-coat hypertension (WCHT), also called 'isolated office or clinic hypertension', is defined as the occurrence of blood pressure (BP) values higher than normal when measured in the medical environment, but within the normal range during daily life, usually defined as average daytime ambulatory BP (ABP) or home BP values (<135 mm Hg systolic and <85 mm Hg diastolic). The prevalence of WCHT varies from 15% to over 50% of all patients with mildly elevated office BP (OBP) values. In untreated hypertensive patients, the probability of WCHT especially increases with female gender and a mildly elevated OBP level. The value of other possible determinants such as (non) smoking status, duration of hypertension, left ventricular mass, number of OBP measurements, educational level, etc. is less consistently shown. Although, for various reasons, studies evaluating the long-term effects of WCHT are not always easy to interpret, most data indicate that persons with WCHT have a worse or equal cardiovascular prognosis than normotensives, but a better one than those with sustained hypertension. WCHT is sometimes considered a prehypertensive state, but data on the long-term evolution of subjects with WCHT are scarce. Patients with WCHT and a high cardiovascular risk or proven target organ damage should be pharmacologically treated. Subjects with uncomplicated WCHT should probably not receive medical therapy, but a close follow-up, including regular assessment of other risk factors and measurement of OBP (every 6 months) and ABP (every 1 or 2 years), is warranted.