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Biomedical subjects

S Shiffman

Publications and source records attributed to S Shiffman.

At least 19 recordsLinked to original sources
PubMed1992

Nicotine elimination and tolerance in non-dependent cigarette smokers.

Although most smokers are nicotine-dependent, recent studies suggest that some very light smokers ("chippers", who smoke fewer than five cigarettes per day) may smoke for decades without developing dependence. It was considered that slowed nicotine elimination and/or reduced nicotine tolerance might underlie chippers' ability to maintain smoking at such low levels. To evaluate this hypothesis, we studied the elimination kinetics and pharmacodynamics of nicotine in chippers and matched regular smokers. Plasma nicotine levels and cardiovascular responses were observed for several hours after subjects were administered uniform doses of tobacco smoke. Chippers did show less chronic nicotine tolerance, but only on some response measures. Their rates of nicotine elimination equaled those of regular smokers. This finding, when coupled with other data about chippers' smoking patterns and nicotine absorption, establish that chippers cannot maintain substantial plasma nicotine levels between cigarettes, and thus suggest that attempts to maintain minimal trough levels of nicotine do not underlie chippers' smoking.

Adult↗
PubMed1992

A history-taking system that uses continuous speech recognition.

Q-MED is an automated history-taking system that uses speaker-independent continuous speech as its main interface modality. Q-MED is designed to allow a patient to enter her basic symptoms by engaging in a dialog with the program. Error-recovery mechanisms help to eliminate findings resulting from misrecognitions or incorrect parses. An evaluation of the natural language parser that Q-MED uses to map user utterances to findings showed an overall semantic accuracy of 87 percent; Q-MED asks more specific questions to capture findings that were not volunteered, or that were unable to be parsed in their initial, open-ended form.

Back Pain↗
PubMed1992

The integration of a continuous-speech-recognition system with the QMR diagnostic program.

We describe a continuous-speech interface for Quick Medical Reference (QMR), which allows physicians to input spoken descriptions of physical-examination findings, or observations. We analyze the difficulties in designing a continuous-speech interface for systems that use medical terminology. We present a method for matching spoken findings names expressed in natural language to QMR terms. The method is based on a semantic representation of findings that both minimize the effect of misrecognition and derive grammars that are necessary for supporting the recognition process.

Diagnosis, Computer-Assisted↗
PubMed1991

Needs and recommendations for behavior research in the prevention and early detection of cancer.

Because life-style patterns affect many cancer risks, research on health-risk behavior and behavior change is critical to cancer prevention. This report recommends priorities for the next decade of psychosocial research on cancer prevention and detection. The leading priority for future research is to fill gaps in basic knowledge left by the rush to intervention and outcome studies. Such research must be theoretically driven and should aim to develop broad principles applicable to diverse health behaviors. Studies that include relevant process data on various stages of behavior change are considered more desirable than simple outcome studies. Epidemiologic investigations should be expanded to include measures of relevant behaviors, so that their impact on clinical outcomes might be established. More research is needed on lay perception of health risks and on individual and health-system barriers to effective cancer prevention and detection. Studies that address the needs of minority and underprivileged populations are crucial. Funding agencies' narrow categorical mandates impede interdisciplinary research on multiple risk factors and their interactions; these boundaries must be relaxed to promote such approaches. Funding agencies should also consider basic research as a long-term investment towards the development of effective interventions.

Health Behavior↗
PubMed1991

Refining models of dependence: variations across persons and situations.

Having established that tobacco smoking is addictive, research should proceed to refine our models of dependence on nicotine and other drugs. Current theories of addiction do not account for between- or within-subjects variations in addictive behavior. Recent evidence that some people can smoke for decades without developing dependence demonstrates the potential for individual differences in vulnerability to dependence. Study of such anomalous smokers may provide insight into the mechanisms underlying nicotine dependence. Current theory and data also fail to provide adequate accounts of situational variation in addictive behavior and of the developmental progression from initial experimentation to dependence.

Humans↗
PubMed1991

A free-text processing system to capture physical findings: Canonical Phrase Identification System (CAPIS).

The task of gathering detailed patient information from free-text medical records presents a significant barrier to clinical research. In this paper, we describe a prototype system for extracting physical examination findings from dictated admission summaries. Our computer program applies a concept-based free-text processing algorithm that identifies user-selected target physical examination findings. We are using the extraction system to enrich an existing clinical database. The system was evaluated by comparing the physical examination findings extracted by our computer program with findings extracted by an independent investigator. Our prototype system was able to recall 92 percent (sensitivity) of the relevant physical findings, with a precision of 96 percent (positive predictive value).

Algorithms↗
PubMed1991

A free-text processing system to capture physical findings: Canonical Phrase Identification System (CAPIS).

The task of gathering detailed patient information from free-text medical records presents a significant barrier to clinical research. In this paper, we describe a prototype system for extracting physical examination findings from dictated admission summaries. Our computer program applies a concept-based free-text processing algorithm that identifies user-selected target physical examination findings. We are using the extraction system to enrich an existing clinical database. The system was evaluated by comparing the physical examination findings extracted by our computer program with findings extracted by an independent investigator. Our prototype system was able to recall 92 percent (sensitivity) of the relevant physical findings, with a precision of 96 percent (positive predictive value).

Academic Medical Centers↗
PubMed1990

Nicotine exposure among nondependent smokers.

Most theories of dependence imply that repeated exposure to an addictive drug leads inexorably to dependence. We examined nicotine exposure in "tobacco chippers," who smoke regularly without developing dependence. Blood samples were obtained before and after 10 chippers (smoking up to 5 cigarettes per day) and 12 dependent smokers (20 to 40 cigarettes per day) smoked a cigarette. Chippers' blood nicotine levels increased significantly, in amounts equaling those of dependent smokers. Assays of cotinine (a long-lasting nicotine metabolite) also suggested that chippers' per-cigarette nicotine absorption equaled that of dependent smokers. Chippers' cotinine levels were also compared with those of heavy smokers (38 cigarettes per day) whose consumption was reduced to 5 cigarettes per day in a previously published study. The heavy smokers compensated by tripling their per-cigarette nicotine intake. Chippers did not seem to be compensating; their cotinine values equaled those expected when regular smokers were not compensating for reduced cigarette availability.

Cotinine↗
PubMed1989

Tobacco "chippers"--individual differences in tobacco dependence.

This study explores the behavior of tobacco "chippers"--very light smokers who regularly use tobacco without developing dependence. Eighteen chippers (CHs) who averaged a maximum of five cigarettes per day, but who smoked at least 4 days per week, were compared to 29 dependent smokers (DSs). Laboratory data showed that CHs inhale cigarette smoke and are exposed to nicotine. In both experimental and retrospective self-report data, CHs showed no signs of tobacco withdrawal when abstinent. CHs also differed from DSs in their pattern of smoking: their smoking was less linked with mood states. However, the hypothesis that they were "social" smokers was contradicted. CHs also differed on psychosocial variables relevant to a stress-coping model of smoking: they reported less stress, better coping, and more social support, but these differences were small. Although the two groups were demographically similar, smoking behavior differences between CHs and DSs were long-standing: the two groups differed in their responses to initial smoking and in their family histories of smoking and cessation. CHs' smoking behavior challenges classical theories of dependence; further research is needed on the factors that may protect CHs from addiction.

Adult↗
PubMed1989

Relapse crises and coping among dieters.

We examined situational antecedents of dieting relapse crises and dieters' attempts to cope with temptations to overeat. We analyzed posttreatment interviews with 57 obese Ss with Type II diabetes, comparing situations in which Ss lapsed with those in which they overcame temptation to overeat. Cluster analysis yielded 3 categories of relapse crises: mealtime, low-arousal, and emotional upset situations. The clusters differed in outcome: Upset situations almost always resulted in overeating; situational factors, especially food-related cues, increased relapse risk; but performance of coping was the strongest correlate of outcome. Cognitive and behavioral coping responses were each equally associated with positive outcomes. When Ss reported combining both types of coping, they were less likely to report overeating. The dynamics of relapse crises among dieters resemble those that govern relapse crises in addictive behaviors.

Adaptation, Psychological↗
PubMed1989

Trans-situational consistency in smoking relapse.

This article explores the question of consistency in ex-smokers' experiences of temptation to smoke. Data were collected from 57 ex-smokers who called a relapse-prevention hotline on two occasions. Relapse situations were classified through cluster analysis and were also coded on McKennel's Smoking Motivation factors. Cognitive and behavioral coping efforts were recorded. Only modest trans-situational consistency was observed. The two relapse episodes did not systematically fall into the same cluster. Data suggested that social aspects of relapse situations might be most consistent. Behavioral coping showed modest trans-situational consistency, whereas cognitive coping showed no stability. The implications of these findings for the prospect of individually tailored interventions are discussed.

Adaptation, Psychological↗
PubMed1988

Self-reported and self-monitored smoking patterns.

Individual differences in smoking patterns are usually assessed with self-report measures such as Horn's Reasons for Smoking Test, which have not been systematically validated. This paper compares results from several self-report scales with self-monitoring data obtained from 164 smoking clinic subjects who monitored their smoking for at least two days. Self-monitoring data were factor-analyzed and correlated with self-report measures. Most of the hypothesized relationships failed to appear. The Sedative Smoking (tension-reduction) factor of the Reasons for Smoking Test received the strongest support. In general, however, the results did not support the validity of commonly-used self-report scales of smoking motives and situations.

Adult↗
PubMed1988

Coping with the temptation to drink.

Part one of this study examined the efficacy of coping responses among college students (N = 137) attempting to control their temptation to drink. Using the taxonomy delineated by Shiffman ("Coping with the Temptation to Smoke, Journal of Consulting and Clinical Psychology, vol. 50, pp. 261-267, 1984), results indicated that both cognitive and behavioral coping were effective in resisting the temptation to drink. When specific coping responses were compared, 3 of 10 behavioral responses and 3 of 13 cognitive responses showed a significant relationship with outcome. These responses were differentially effective in resisting the temptation to drink. A comparison was made to Shiffman's (1984) previous work and the conceptual and methodological problems which may account for the divergent results are discussed. Part Two of this study examined the relationship between the coping responses people use in attempting self-control and those used in dealing with daily stressors. Results suggest that coping is a highly situationally specific response which shows little consistency across these two contexts. Conceptual and methodological difficulties which qualify the obtained results are discussed.

Adaptation, Psychological↗
PubMed1988

Negative affect smoking and smoking relapse.

This study examined linkages between negative affect smoking and relapse. A sample of 669 smokers treated in smoking cessation clinics completed the Horn Motives for Smoking Scale at baseline and were followed at 3 and 12 months posttreatment. Negative affect (NA) smoking scores were unrelated to initial cessation or to maintenance at 3 months. Negative affect accounted for 8% of the variance in 12-month outcomes. The findings support the conceptual distinction between cessation and maintenance and suggest the need to distinguish stages within maintenance. The study also examined whether NA was associated with experiencing relapse crises in negative affect situations. Reports of relapse crises (situations leading to smoking or to the verge of smoking) were obtained from 572 subjects at the 3-month follow-up. Negative affect smokers were more likely to report that the crises were precipitated by negative affect. Although weak, this link between baseline smoking patterns and relapse situations suggests the possibility of individually tailored treatments.

Adolescent↗
PubMed1988

The effect of nicotine on the delay of gastric emptying.

The effect of cigarette smoking and its active component, nicotine, on the gastric emptying of solid food was assessed in a randomized double-blind crossover design. Ten regular smokers were studied after a 6 h fast and least 18 h after their last cigarette. Subjects smoked a total of three high (1.91 mg) or low (0.17 mg) nicotine cigarettes, before and after a technetium-labelled solid meal and were scanned by gamma camera periodically over a 2-h period. All calculations of gastric emptying revealed a significant delay after smoking high versus low nicotine cigarettes in: mean per cent isotope remaining in the stomach at each measurement point from 90-120 min; amount of meal remaining in the stomach at 2 h; and mean time at which 50% of the meal had emptied (T1/2). Delay in gastric emptying was significantly correlated with increase in serum nicotine concentration on the high nicotine day.

Adult↗
PubMed1986

A cluster-analytic classification of smoking relapse episodes.

Using reports of relapse crises collected through a relapse prevention hotline, this paper develops a taxonomy of relapse situations. Cluster analysis resulted in four clusters. Social situations are characterized by social drinking and exposure to smoking. Relaxation situations are marked by relaxation, usually after a meal. Work situations take place during work when the exsmoker is feeling anxious. Upset situations occur when the exsmoker is feeling anxious or depressed while home alone. These situations were significantly discriminated by their scores on the McKennel Smoking Motivation Scales, suggesting a connection between smoking patterns and relapse. Behavioral coping was less likely and relapse more likely in social and upset situations. The frequency of coping accounted for the higher relapse rates in Upset, but not in social situations. Relapse was nearly inevitable among people who failed to cope behaviorally in social situations, suggesting that they are especially tempting.

Affective Symptoms↗
PubMed1985

Smoking relapse situations: a preliminary typology.

This paper presents a preliminary attempt to develop a typology of smoking relapse episodes based on cluster analysis. Descriptions of relapse or near-relapse episodes were collected from 183 ex-smokers. Cluster analysis of 53 cases revealed five clusters in two groups distinguished by a positive (Type I) versus negative (Type II) affective tone. Type Ia situations involve drinking alcohol with others who are smoking. Type Ib situations are associated with relaxation. Type Ic episodes are associated with withdrawal symptoms. Type IIa situations involve anxiety related to work stress. Type IIb episodes occur when the ex-smoker is inactive and bored. Type Ia situations are associated with less behavioral coping and more relapse than the others.

Adaptation, Psychological↗