03221nas a2200385 4500008004100000022001400041245015700055210006900212260001600281300001100297490000800308520208200316653000902398653002802407653002902435653003702464653002802501653001102529653001102540653001702551653000902568653003502577653001802612100001502630700001902645700001602664700001502680700001702695700001802712700001702730700001602747700002002763700001602783856003602799 1995 eng d a0098-748400aTemporal patterns of antihypertensive medication use among older adults, 1989 through 1992. An effect of the major clinical trials on clinical practice?0 aTemporal patterns of antihypertensive medication use among older c1995 May 10 a1436-80 v2733 a

OBJECTIVE: To describe the changing patterns of antihypertensive medication use in the years immediately before and after the publication of the results of three major clinical trials of the treatment of hypertension in older adults.

DESIGN: In this cohort study, adults 65 years or older were examined annually on four occasions between June 1989 and May 1992, and the use of antihypertensive medications was assessed by inventory at each visit. The four visits defined the boundaries of three study periods. For each study period, participants receiving antihypertensive therapy were either continuous users (n = 1667, 1643, and 1605, respectively) or starters (n = 157, 142, 120) of hypertensive therapy. The large clinical trials that convincingly proved the efficacy and safety of low-dose diuretic therapy in older adults were published during the latter parts of period 2 and the early parts of period 3.

RESULTS: Among starters, the proportion initiating therapy on diuretics increased from 35.9% in period 2 to 47.5% in period 3, significantly so among women (P = .04). The proportions initiating other drugs displayed no significant trends. Among continuous users, the use of diuretics, beta-blockers, and vasodilators generally decreased over the 3-year period, while the use of calcium channel blockers and angiotensin-converting enzyme inhibitors increased significantly in each of the three periods (P < .05). The decline of 2.7% in the prevalence of diuretic use in period 1 abated during period 2 (1.8% decline), and it slowed significantly (P = .03) to almost a complete halt during period 3 (0.2% decline). The rate of increase in the use of calcium channel blockers slowed significantly (P = .01) between period 1 (+6.7%) and period 3 (+2.8%).

CONCLUSIONS: Although other factors such as cost may have been important, the temporal trends in antihypertensive drug therapy coincided in time with and may have reflected in part the influence of the major clinical trials on the patterns of clinical practice.

10aAged10aAntihypertensive Agents10aClinical Trials as Topic10aData Interpretation, Statistical10aDrug Utilization Review10aFemale10aHumans10aHypertension10aMale10aPractice Patterns, Physicians'10aUnited States1 aPsaty, B M1 aKoepsell, T, D1 aYanez, N, D1 aSmith, N L1 aManolio, T A1 aHeckbert, S R1 aBorhani, N O1 aGardin, J M1 aGottdiener, J S1 aRutan, G, H uhttps://chs-nhlbi.org/node/141801637nas a2200193 4500008004100000022001400041245012700055210006900182260001600251300001300267490000700280520103900287653000901326653001801335100001601353700001801369700002001387856003601407 1998 eng d a0277-671500aThe effects of measurement error in response variables and tests of association of explanatory variables in change models.0 aeffects of measurement error in response variables and tests of  c1998 Nov 30 a2597-6060 v173 a

Biomedical studies often measure variables with error. Examples in the literature include investigation of the association between the change in some outcome variable (blood pressure, cholesterol level etc.) and a set of explanatory variables (age, smoking status etc.). Typically, one fits linear regression models to investigate such associations. With the outcome variable measured with error, a problem occurs when we include the baseline value of the outcome variable as a covariate. In such instances, one can find a relationship between the observed change in the outcome and the explanatory variables even when there is no association between these variables and the true change in the outcome variable. We present a simple method of adjusting for a common measurement error bias that tends to be overlooked in the modelling of associations with change. Additional information (for example, replicates, instrumental variables) is needed to estimate the variance of the measurement error to perform this bias correction.

10aBias10aLinear Models1 aYanez, N, D1 aKronmal, R, A1 aShemanski, L, R uhttps://chs-nhlbi.org/node/151802729nas a2200385 4500008004100000022001400041245011700055210006900172260001300241300001100254490000700265520167500272653000901947653001901956653002101975653002801996653002302024653002402047653001102071653002202082653001102104653000902115653002602124653001402150653001702164653001102181653001802192100001802210700001602228700001602244700001502260700001602275700001702291856003502308 2000 eng d a0735-109700aPrevalence, predisposing factors, and prognosis of clinically unrecognized myocardial infarction in the elderly.0 aPrevalence predisposing factors and prognosis of clinically unre c2000 Jan a119-260 v353 a

OBJECTIVES: This study was designed to determine the prevalence of unrecognized myocardial infarction (UMI), as well as risk factors, and to compare prognosis after detection of previously UMI to that after recognized myocardial infarction (RMI).

BACKGROUND: Past studies revealed that a significant proportion of MIs escape recognition, and that prognosis after such events is poor, but the epidemiology of UMI has not been reassessed in the contemporary era.

METHODS: The Cardiovascular Health Study (CHS) database, composed of individuals > or =65, was queried for participants who, at entry, demonstrated electrocardiographic evidence of a prior Q-wave MI, but who lacked a history of this diagnosis. The features and outcomes of this group were compared to those of individuals with prevalent RMI.

RESULTS: Of 5,888 participants, 901 evidenced a past MI, and 201 (22.3%) were previously unrecognized. The independent predictors of UMI were the absence of angina and the absence of congestive heart failure (CHF). Six-year mortality did not significantly differ between the two groups.

CONCLUSIONS: 1) In the elderly, UMI continues to represent a significant proportion of all MIs; 2) associations with angina and CHF may reflect complex neurological issues, but they also may represent diagnosis bias; 3) these individuals can otherwise not be distinguished from those with recognized infarctions; and 4) mortality rates after UMI and RMI are similar. Future studies should address screening for UMI, risk stratification after detection of previously UMI, and the role of standard post-MI therapies.

10aAged10aCause of Death10aCoronary Disease10aCross-Sectional Studies10aDatabases, Factual10aElectrocardiography10aFemale10aFollow-Up Studies10aHumans10aMale10aMyocardial Infarction10aPrognosis10aRisk Factors10aStroke10aSurvival Rate1 aSheifer, S, E1 aGersh, B, J1 aYanez, N, D1 aAdes, P, A1 aBurke, G, L1 aManolio, T A uhttps://chs-nhlbi.org/node/607