How to Measure Propensity to Take Risks in the Italian Context: The Italian Validation of the Risk Propensity Scale

Risk propensity is a multifaced construct that influences many aspects of life, such as decision making. In the present study, the psychometric characteristics of the Risk Propensity Scale (RPS) have been explored for the first time in an Italian sample. The RPS is a 7 item self-report questionnaire measuring people's tendency to take risks. The English RPS has been translated following the forward-backwards translation method, and it was filled out by 199 participants. Since its dimensionality has never been explored before, its factor structure has been analysed with exploratory factor analysis that confirmed the one-factor structure of the questionnaire and the retention of all the items. The Italian version of the RPS has high internal consistency (Cronbach alphas .78), and almost all the items were positively and significantly correlated. The convergent and discriminant validity, analysed by considering the associations with decision-making styles and an implicit measure of risk propensity, were satisfactory. Overall, the Italian version of the RPS is a valid and quick questionnaire useful to measure propensity to take risks in the Italian context.

A multicenter randomized trial for quality of life evaluation by non-invasive intelligent tools during post-curative treatment follow-up for head and neck cancer: Clinical study protocol

Patients surviving head and neck cancer (HNC) suffer from high physical, psychological, and socioeconomic burdens. Achieving cancer-free survival with an optimal quality of life (QoL) is the primary goal for HNC patient management. So, maintaining lifelong surveillance is critical. An ambitious goal would be to carry this out through the advanced analysis of environmental, emotional, and behavioral data unobtrusively collected from mobile devices. The aim of this clinical trial is to reduce, with non-invasive tools (i.e., patients' mobile devices), the proportion of HNC survivors (i.e., having completed their curative treatment from 3 months to 10 years) experiencing a clinically relevant reduction in QoL during follow-up. The Big Data for Quality of Life (BD4QoL) study is an international, multicenter, randomized (2:1), open-label trial. The primary endpoint is a clinically relevant global health-related EORTC QLQ-C30 QoL deterioration (decrease ≥10 points) at any point during 24 months post-treatment follow-up. The target sample size is 420 patients. Patients will be randomized to be followed up using the BD4QoL platform or per standard clinical practice. The BD4QoL platform includes a set of services to allow patients monitoring and empowerment through two main tools: a mobile application installed on participants' smartphones, that includes a chatbot for e-coaching, and the Point of Care dashboard, to let the investigators manage patients data. In both arms, participants will be asked to complete QoL questionnaires at study entry and once every 6 months, and will undergo post-treatment follow up as per clinical practice. Patients randomized to the intervention arm (n=280) will receive access to the BD4QoL platform, those in the control arm (n=140) will not. Eligibility criteria include completing curative treatments for non-metastatic HNC and the use of an Android-based smartphone. Patients undergoing active treatments or with synchronous cancers are excluded. Clinical Trial Registration: ClinicalTrials.gov, identifier (NCT05315570).

After the Pandemic: The Future of Italian Medicine. The Psychological Impact of COVID-19 on Medical and Other Healthcare-Related Degrees Students

Objective: The study aimed to explore the psychological symptoms and the readiness to fight the pandemic of the new generation of healthcare professionals: medical and other healthcare degree students. Methods: We enrolled 509 medical and healthcare-related degree students during the second outbreak of COVID-19 in Italy. We have examined their psychological symptoms using the 12-item General Health Questionnaire (GHQ-12) and their readiness to fight the pandemic together with their academic career status, their relationship with the university, and their emotional reactions to the pandemic with Visual Analog Scales. Results: We retrieved a GHQ mean of 21.65 (SD = 40.63) and readiness to fight the pandemic mean of 53.58 (SD = 31.49). Perceived control affects variables: a negative effect on psychological symptoms and a positive effect on the willingness to fight the pandemic. The other variables with an impact were stress, loneliness, and anger that had a significant and positive impact on psychological symptoms. Age and concern for patients had a significant positive impact on readiness to fight for the pandemic, while years of attendance had a significant but negative impact. Conclusion: Universities and Institutions should consider the impact of the pandemic on students, in particular, for its effect on their mental health.

Emotional Tone, Analytical Thinking, and Somatosensory Processes of a Sample of Italian Tweets During the First Phases of the COVID-19 Pandemic: Observational Study

BACKGROUND

The COVID-19 pandemic is a traumatic individual and collective chronic experience, with tremendous consequences on mental and psychological health that can also be reflected in people's use of words. Psycholinguistic analysis of tweets from Twitter allows obtaining information about people's emotional expression, analytical thinking, and somatosensory processes, which are particularly important in traumatic events contexts.

OBJECTIVE

We aimed to analyze the influence of official Italian COVID-19 daily data (new cases, deaths, and hospital discharges) and the phase of managing the pandemic on how people expressed emotions and their analytical thinking and somatosensory processes in Italian tweets written during the first phases of the COVID-19 pandemic in Italy.

METHODS

We retrieved 1,697,490 Italian COVID-19-related tweets written from February 24, 2020 to June 14, 2020 and analyzed them using LIWC2015 to calculate 3 summary psycholinguistic variables: emotional tone, analytical thinking, and somatosensory processes. Official daily data about new COVID-19 cases, deaths, and hospital discharges were retrieved from the Italian Prime Minister's Office and Civil Protection Department GitHub page. We considered 3 phases of managing the COVID-19 pandemic in Italy. We performed 3 general models, 1 for each summary variable as the dependent variable and with daily data and phase of managing the pandemic as independent variables.

RESULTS

General linear models to assess differences in daily scores of emotional tone, analytical thinking, and somatosensory processes were significant (F6,104=21.53, P<.001, R2= .55; F5,105=9.20, P<.001, R2= .30; F6,104=6.15, P<.001, R2=.26, respectively).

CONCLUSIONS

The COVID-19 pandemic affects how people express emotions, analytical thinking, and somatosensory processes in tweets. Our study contributes to the investigation of pandemic psychological consequences through psycholinguistic analysis of social media textual data.

When in doubt, Google it: distress-related information seeking in Italy during the COVID-19 pandemic

BACKGROUND

Psychological health has been one of the aspects affected by the recent COVID-19 pandemic. We aim to evaluate the patterns of Google search for mental distress symptoms of Italian citizens during the various phases of the COVID-19 pandemic.

METHODS

We assessed Google searches for psychological-health related words. We gathered and analyzed data on daily search queries on depression, anxiety, and insomnia from Google Trends, in a time ranging from the Pre-COVID phase (beginning 25th January 2020) up to the second wave phase (ending 17th October 2020). We performed three general linear models on search trends of the three words and tested whether and to what extent official data about new cases of COVID-19, information searching on new cases, and the government health measures impacted on these trends.

RESULTS

Average daily search queries were higher for anxiety, followed by depression and insomnia. General linear models performed to assess differences in daily search queries for anxiety, depression and insomnia were significant, respectively [F(13, 253) = 6.80, P < .001]; [F(13, 253) = 10.25, P < .001]; [F(13, 253) = 6.61, P < .001]. Specifically, daily search queries differed among different phases of managing the COVID-19 outbreak: anxiety [F(5, 253) = 10.35, P < .001, [Formula: see text] = .17]; depression [F(5, 253) = 13.59, P < .001, [Formula: see text] = .21]; insomnia [F(5, 253) = 3.52, P = .004, [Formula: see text] = .07].

CONCLUSIONS

Our study contributed to the investigation of online information-seeking behaviors of Italians regarding mental health throughout the entire phase of the pandemic and provides insights on the possible future trends of mental distress during upcoming pandemic phases.

Taking into Account Patient Preferences: A Consensus Study on the Assessment of Psychological Dimensions Within Patient Preference Studies

Patient preferences are gaining recognition among key stakeholders involved in benefit-risk decision-making along the medical product lifecycle. However, one of the main challenges of integrating patient preferences in benefit-risk decision-making is understanding differences in patient preference, which may be attributable to clinical characteristics (eg age, medical history) or psychosocial factors. Measuring the latter may provide valuable information to decision-makers but there is limited guidance regarding which psychological dimensions may influence patient preferences and which psychological instruments should be considered for inclusion in patient preference studies. This paper aims to provide such guidance by advancing evidence and consensus-based recommendations and considerations. Findings of a recent systematic review on psychological constructs having an impact on patients' preferences and health-related decisions were expanded with input from an expert group (n = 11). These data were then used as the basis for final recommendations developed through two rounds of formal evaluation via an online Delphi consensus process involving international experts in the field of psychology, medical decision-making, and risk communication (n = 27). Three classes of recommendations emerged. Eleven psychological constructs reached consensus to be recommended for inclusion with the strongest consensus existing for health literacy, numeracy, illness perception and treatment-related beliefs. We also proposed a set of descriptive and checklist criteria to appraise available psychological measures to assist researchers and other stakeholders in including psychological assessment when planning patient preference studies. These recommendations can guide researchers and other stakeholders when designing and interpreting patient preference studies with a potential high impact in clinical practice and medical product benefit-risk decision-making processes.

“Optimism Is a Strategy for Making a Better Future”

Abstract. Cancer is a deadly disease that can lead to psychological suffering and decreased quality of life (QoL). Personality has been proven to have an effect on QoL and, in particular, Dispositional Optimism (DO) has been studied in relation to overcoming health crisis. The aim of this systematic review is to deepen the state of art of the relationship between QoL and DO in cancer patients. PubMed and Embase databases were systematically searched. Fifteen studies were included with a total of 5,249 cancer patients. All of the studies consider the relationship between DO and QoL, some studies analyze the correlation between the two variables and found a positive association. The majority of the studies investigate the predictive power of DO over QoL and most of them found DO to be predictive of a higher QoL. Results confirmed the association between DO and QoL in a sample of cancer patients. These results could influence the clinical practice as DO has been proven to have a beneficial effect on mental and physical health.

Patients' experience with MRI-guided in-bore biopsy versus TRUS-guided biopsy in prostate cancer: a pilot study

Background

Ultrasound-guided magnetic resonance imaging (MRI)-fusion biopsy and in-bore MRI-guided biopsy (MRGB) have improved the diagnostic pathway in patients with suspected prostate cancer compared to the traditional random sampling of the prostate gland under transrectal ultrasound guidance (TRUS-Bx). The aim of our study was to assess the psychological experiences of patients undergoing MRGB and TRUS-Bx.

Method

Participants completed an ad hoc set of 11 items to be rated from 0 (not at all) to 10 (very much) on visual analogue scales and one open question on the most worrisome aspect of the procedure. The set of items evaluated satisfaction with the information received and the possibility to ask questions to the staff; the tolerability of the irritation, duration and discomfort associated with the exam; their level of worry or calm before the exam; the perceived need to undergo the exam; their satisfaction with the exam and willingness to repeat it in the future; and acceptability of the exam.

Results

Between May 2018 and June 2019, 47 participants were enrolled on the day of their MRGB; 24 had previously undergone TRUS-Bx. The MRGB was rated with high positive scores on all 11 items. The lowest ratings regarded the duration of the exam (mean = 6.6) and feeling calm (mean = 6.6). Participants were significantly more satisfied with MRGB than TRUS-Bx, rating it as less painful and more comfortable, necessary and tolerable.

Conclusion

These preliminary results indicate that the MRGB is likely to be more tolerable and acceptable to patients than TRUS-Bx.

2020s Heroes Are Not Fearless: The Impact of the COVID-19 Pandemic on Wellbeing and Emotions of Italian Health Care Workers During Italy Phase 1

Objective

The study aimed to investigate the mental health and emotional reaction of physicians working during phase 1 of the COVID-19 pandemic in Italy.

Methods

A total of 458 Italian Health Care Workers (HCWs) working during phases 1 of the COVID-19 outbreak were voluntarily enlisted in the study and recruited with the snowball technique through an online survey. We examined our variables with the General Health Questionnaire – 12 and with Visual Analog Scales.

Results

The sample has a high level of psychological distress 21.26 (SD = 4.46), the emotional reaction was characterized by high level of fear for family members and cohabitants (M = 77.67, SD = 27.16) and patients (M = 67.16, SD = 27.71). Perceived control, fear for patients, and for family members and cohabitants, feeling alone and anger all contribute to a decreased mental health in Italian physicians (R² = 0.285, p < 0.001).

Conclusion

Italian HCWs’ mental health and emotional reaction have to be considered to prevent high risk of burnout and post-traumatic stress disorder (PTSD). It becomes pivotal in the next months to implement a tailored psychological intervention to take care of HCWs and to prevent costly consequences for them, patients, and the healthcare system.

Genetic Testing Consumers in Italy: A Preliminary Investigation of the Socio-Demographic Profile, Health-Related Habits, and Decision Purposes

Aim of the study: Genetic testing is becoming increasingly common in clinical practice and health management; nonetheless, little is known about how the population approaches genetic services through private companies. Our study aims to describe socio-demographic aspects, health-related habits, and overall beliefs and knowledge about genetic risk and testing in a population of Italian citizens who decided to undergo a genetic examination through a private genetic company.

Study design: A sample of 152 clients from an Italian private genetic company completed an ad-hoc survey from September 2016 to February 2018, addressing socio-demographic data, health habits, psycho-physic condition, perceived utility of genetic results, decision purposes about data sharing, and behavioral changes after results.

Results: Participants (mean age 42.4) were predominantly female (82.2%) and were overall well-educated. Their main source of information were physicians (77%), and 41.1% entrusted the management of results to the same. Thirty-eight percentage underwent genetic analysis for cancer predisposition, 31.3% for fertility problems, 24% for dietary or intolerance issues in the period of enrolment. More than half of them (62.7%) reported a family history of the disease, and overall 69% had a current or past experience with a disease. Clients perceived the genetic screening as useful to adopt behaviors that may prevent disease onset (37.7%), to know their “real health status” (27.4%), and to adopt health-related behaviors (23.3%). 62.8% claimed they were motivated to change behaviors after results (healthier diet, practice exercise, medical checks), and they wanted to share results with their physician and family members.

Discussion/Conclusion: The overview of consumers' profiles in Italy and other European countries can contribute to tailoring and regulating genetic services in a way that could be efficient in terms of healthy choices, behaviors, and health resource expenditures for the general public.

Spontaneous Participation in Secondary Prevention Programs: The Role of Psychosocial Predictors

Disease prevention is a multifaceted construct that has been widely studied. Nevertheless, in spite of its importance, it is still not sufficiently considered by the general population. Since the reasons for this lack of consideration are not yet fully understood, we created an Online Prevention Survey (OPS) to investigate the role of both sociodemographic and psychological factors in predicting individuals’ spontaneous participation in secondary prevention programs. The results revealed that younger people, men, manual workers, unemployed people, and those who do not regularly practise physical activity were less likely to spontaneously participate in such programs. Furthermore, an analysis of the psychological determinants of the willingness to participate in secondary prevention programs showed that depressive symptoms negatively predict it, while an individual’s perception of receiving high social support acts as a positive predictor. Based on these results, we suggest the need for implementing new tailored approaches to promote prevention initiatives to those segments of the population which are more reluctant to spontaneously undertake prevention paths.

Patients' health locus of control and preferences about the role that they want to play in the medical decision-making process

Health locus of control (HLOC) may influence people's behavior regarding their health as well as their desires to be involved in the medical decision-making. Our study aimed to examine HLOC's relations with people's control preferences about the medical decision-making. A total of 153 people filled out the self-administered version of the Control Preference Scale and the Multidimensional Health Locus of Control Scale - form C. The most preferred role is the collaborative one. However, HLOC explained heterogeneity in people's control preferences: lower scores in external HLOC were related to a greater preference for the active and the collaborative role. From the personalized medicine perspective, an accurate evaluation of the patient's HLOC could help tailoring the decision-making process within the clinical context.

Sexism Interacts with Patient-Physician Gender Concordance in Influencing Patient Control Preferences: Findings from a Vignette Experimental Design

BACKGROUND

Patient preferences regarding their involvement in shared treatments decisions is fundamental in clinical practice. Previous evidences demonstrated a large heterogeneity in these preferences. However, only few studies have analysed the influence of patients' individual differences, contextual and situational qualities, and their complex interaction in explaining this variability.

METHODS

We assessed the role of the interaction of patient's sociodemographic and psychological factors with a physician's gender. Specifically, we focused on patient gender and attitudes toward male or female physicians. One hundred fifty-three people participated in this randomised controlled study and were randomly assigned to one of two experimental conditions in which they were asked to imagine discussing their treatment with a male and a female doctor.

RESULTS

Analyses showed an interplay between attitude towards women and the gender of patients and doctors, explaining interindividual variability in patient preferences.

CONCLUSIONS

In conclusion, patients' attitudes toward the physicians' gender constitutes a relevant characteristic that may influence the degree of control patients want to have and the overall patient-physician relationship.

The clinical-care focused psychological interview (CLiC): a structured tool for the assessment of cancer patients' needs

Integrating the psychosocial perspective in oncology is warranted. Here, we introduce a structured psychological intervention, the clinical-care focused psychological interview (CLiC), to address patients' needs in the relationship with health professionals, clinical pathway and decision-making process. The perceived utility and feasibility of the CLiC were evaluated in a preliminary sample of 30 patients who were candidates to undergo a radical cystectomy at the European Institute of Oncology, Milan, Italy. Patients reported a very high satisfaction with the interview, because it prepared them for their upcoming surgery by gathering more information about their clinical pathway and allowed them to discover the information they still needed. 30% stated that CLiC helped them to reorganise their thoughts and 36.7% understood the role of psychological intervention in the clinical pathway. Only 20% considered the CLiC useful in helping to build their relationship with the clinical staff. Before an invasive surgery such as radical cystectomy, patients' need for information regarding the upcoming surgery seems to prevail. Knowing the future consequences and adjusting toward the disease could be paramount for patients in facing uncertainty and they might feel that creating a relationship with physicians could be a secondary issue. However, our data show that a structured psychological intervention such as the CLiC interview can collect important information for patients and healthcare professionals to develop real patient-centred care.

Design, Conduct, and Use of Patient Preference Studies in the Medical Product Life Cycle: A Multi-Method Study

Objectives: To investigate stakeholder perspectives on how patient preference studies (PPS) should be designed and conducted to allow for inclusion of patient preferences in decision-making along the medical product life cycle (MPLC), and how patient preferences can be used in such decision-making.

Methods: Two literature reviews and semi-structured interviews (n = 143) with healthcare stakeholders in Europe and the US were conducted; results of these informed the design of focus group guides. Eight focus groups were conducted with European patients, industry representatives and regulators, and with US regulators and European/Canadian health technology assessment (HTA) representatives. Focus groups were analyzed thematically using NVivo.

Results: Stakeholder perspectives on how PPS should be designed and conducted were as follows: 1) study design should be informed by the research questions and patient population; 2) preferred treatment attributes and levels, as well as trade-offs among attributes and levels should be investigated; 3) the patient sample and method should match the MPLC phase; 4) different stakeholders should collaborate; and 5) results from PPS should be shared with relevant stakeholders. The value of patient preferences in decision-making was found to increase with the level of patient preference sensitivity of decisions on medical products. Stakeholders mentioned that patient preferences are hardly used in current decision-making. Potential applications for patient preferences across industry, regulatory and HTA processes were identified. Four applications seemed most promising for systematic integration of patient preferences: 1) benefit-risk assessment by industry and regulators at the marketing-authorization phase; 2) assessment of major contribution to patient care by European regulators; 3) cost-effectiveness analysis; and 4) multi criteria decision analysis in HTA.

Conclusions: The value of patient preferences for decision-making depends on the level of collaboration across stakeholders; the match between the research question, MPLC phase, sample, and preference method used in PPS; and the sensitivity of the decision regarding a medical product to patient preferences. Promising applications for patient preferences should be further explored with stakeholders to optimize their inclusion in decision-making.

The patient perspective: investigating patient empowerment enablers and barriers within the oncological care process

Patient empowerment is a multi-factorial concept and its relevance has led to a growing body of literature; despite this attention, there is still no agreement regarding the elements that define its expression. While several studies have already investigated the positive effect of empowerment interventions on the care process outcome, the aim of this study is to investigate which factors can foster an empowered management of the cancer condition from the patient's perspective. To examine patients' perception of empowerment enablers, we asked for participants' input on the role of three factors frequently cited as positively affected by empowerment: care quality, perception of direct control and relationships within the care context, during the care process. Three focus groups were conducted with 34 cancer patients. The results highlight the perception of direct control on their treatment as the least valued element (2.87, SD 0.566) when compared with care quality (3.75, SD 0.649) and relational support in the care context (3.91, SD 0.274). Unlike traditional approaches to empowerment, patient's expression of empowerment does not mainly reside in the direct control of their condition as much as in an active role within the relationship with caretakers, such as the ability to choose the doctor, the care team or the health organisation in charge of their healthcare. Emerging aspects from this analysis of patient's perspective are central in order to adequately consider empowerment in the care process and to provide more effective care strategies.

Training Cognitive Functions Using Mobile Apps in Breast Cancer Patients: Systematic Review

Background

Breast cancer is an invalidating disease and its treatment can bring serious side effects that have a physical and psychological impact. Specifically, cancer treatment generally has a strong impact on cognitive function. In recent years, new technologies and eHealth have had a growing influence on health care and innovative mobile apps can be useful tools to deliver cognitive exercise in the patient’s home.

Objective

This systematic review gives an overview of the state-of-the-art mobile apps aimed at training cognitive functions to better understand whether these apps could be useful tools to counteract cognitive impairment in breast cancer patients.

Methods

We searched in a systematic way all the full-text articles from the PubMed and Embase databases.

Results

We found eleven studies using mobile apps to deliver cognitive training. They included a total of 819 participants. App and study characteristics are presented and discussed, including cognitive domains trained (attention, problem solving, memory, cognitive control, executive function, visuospatial function, and language). None of the apps were specifically developed for breast cancer patients. They were generally developed for a specific clinical population. Only 2 apps deal with more than 1 cognitive domain, and only 3 studies focus on the efficacy of the app training intervention.

Conclusions

These results highlight the lack of empirical evidence on the efficacy of currently available apps to train cognitive function. Cognitive domains are not well defined across studies. It is noteworthy that no apps are specifically developed for cancer patients, and their applicability to breast cancer should not be taken for granted. Future studies should test the feasibility, usability, and effectiveness of available cognitive training apps in women with breast cancer. Due to the complexity and multidimensionality of cognitive difficulties in this cancer population, it may be useful to design, develop, and implement an ad hoc app targeting cognitive impairment in breast cancer patients.

The size, shape, density and ring of the dwarf planet Haumea from a stellar occultation

Haumea-one of the four known trans-Neptunian dwarf planets-is a very elongated and rapidly rotating body. In contrast to other dwarf planets, its size, shape, albedo and density are not well constrained. The Centaur Chariklo was the first body other than a giant planet known to have a ring system, and the Centaur Chiron was later found to possess something similar to Chariklo's rings. Here we report observations from multiple Earth-based observatories of Haumea passing in front of a distant star (a multi-chord stellar occultation). Secondary events observed around the main body of Haumea are consistent with the presence of a ring with an opacity of 0.5, width of 70 kilometres and radius of about 2,287 kilometres. The ring is coplanar with both Haumea's equator and the orbit of its satellite Hi'iaka. The radius of the ring places it close to the 3:1 mean-motion resonance with Haumea's spin period-that is, Haumea rotates three times on its axis in the time that a ring particle completes one revolution. The occultation by the main body provides an instantaneous elliptical projected shape with axes of about 1,704 kilometres and 1,138 kilometres. Combined with rotational light curves, the occultation constrains the three-dimensional orientation of Haumea and its triaxial shape, which is inconsistent with a homogeneous body in hydrostatic equilibrium. Haumea's largest axis is at least 2,322 kilometres, larger than previously thought, implying an upper limit for its density of 1,885 kilograms per cubic metre and a geometric albedo of 0.51, both smaller than previous estimates. In addition, this estimate of the density of Haumea is closer to that of Pluto than are previous estimates, in line with expectations. No global nitrogen- or methane-dominated atmosphere was detected.

Preparative-scale amino acid separation by thermal parametric pumping on an ion-exchange resin

Thermal parametric pumping was experimentally investigated for the concentration and separation of amino acids. Previous theories of parametric pumping were improved by taking into account dissociation equilibria in the liquid phase. Experiments were carried out with a mixture of glutamic acid, aspartic acid, serine and threonine in a highly acidic solution (HCl). A multi-component equilibrium model was mainly used to simulate the experimental results and to investigate the effect of chloride concentration over a wide range. It is shown that it is always possible to concentrate the amino acids and to separate some of them under certain conditions.

Preliminary pharmacokinetics and pharmacodynamics of an ultra-short-acting opioid: remifentanil (GI87084B)

Remifentanil is a newly synthesized 4-anilido-piperidine with an ester side chain susceptible to esterase metabolism. We evaluated the safety, analgesic efficacy, and pharmacokinetics of remifentanil in 48 male volunteers. Volunteers were randomized to receive increasing doses of remifentanil, alfentanil, or placebo. Analgesic efficacy was evaluated by increasing tolerance to a spring-loaded rod measured at the tibia and sternum at multiple time points. Respiratory depression was measured by changes in arterial blood gas tensions and peripheral hemoglobin oxygen saturation. Hemodynamics were continuously monitored by means of an intra-arterial catheter. Both remifentanil and alfentanil produced a dose-dependent increase in analgesia and respiratory depression. Remifentanil was 20 to 30 times more potent (milligram to milligram) than alfentanil when assessed by either analgesic efficacy or respiratory measures. The pharmacokinetics of remifentanil were best described by a biexponential decay curve. Remifentanil had a small volume of distribution of 0.39 (SD, +/- 0.25) L/kg (alfentanil, 0.52 +/- 2 L/kg), with a rapid distribution phase of 0.94 (SD, +/- 0.57) min and an extremely short elimination half-life of 9.5 (SD, +/- 4) min compared with an elimination half-life of alfentanil of 58 (SD, +/- 7.6) min. The t1/2 ke0 (half-time for equilibration between plasma and the effect compartment) of remifentanil for analgesia was calculated as 1.3 min. Thus, remifentanil appears to have a pharmacologic profile similar to other potent mu agonists, but with exceptionally short-lasting pharmacokinetics, which is likely to make it a very useful opioid for clinical practice.