While Problem Based Learning (PBL) has long been established internationally, Team-based learning (TBL) is a relatively new pedagogy in medical curricula. Both PBL and TBL are designed to facilitate a learner-centred approach, where students, in interactive small groups, use peer-assisted learning to solve authentic, professionally relevant problems. Differences, however, exist between PBL and TBL in terms of preparation requirements, group numbers, learning strategies, and class structure. Although there are many similarities and some differences between PBL and TBL, both rely on constructivist learning theory to engage and motivate students in their learning. The aim of our study was to qualitatively explore students’ perceptions of having their usual PBL classes run in TBL format.In 2014, two iterations in a hybrid PBL curriculum were converted to TBL format, with two PBL groups of 10 students each, being combined to form one TBL class of 20, split into four groups of five students. At the completion of two TBL sessions, all students were invited to attend one of two focus groups, with 14 attending. Thematic analysis was used to code and categorise the data into themes, with constructivist theory used as a conceptual framework to identify recurrent themes.Four key themes emerged; guided learning, problem solving, collaborative learning, and critical reflection. Although structured, students were attracted to the active and collaborative approach of TBL. They perceived the key advantages of TBL to include the smaller group size, the preparatory Readiness Assurance Testing process, facilitation by a clinician, an emphasis on basic science concepts, and immediate feedback. The competitiveness of TBL was seen as a spur to learning. These elements motivated students to prepare, promoted peer assisted teaching and learning, and focussed team discussion. An important advantage of PBL over TBL, was the opportunity for adequate clinical reasoning within the problem solving activity.Students found their learning experience in TBL and PBL qualitatively different. There were advantages and disadvantages to both. This suggests a hybrid approach utilising the strengths of both methods should be considered for wide scale implementation. Introduced over half a century ago, problem-based learning (PBL) has long been accepted as a cornerstone in many medical education curricula worldwide. However, in re-designing curricula, medical educators need to balance producing graduates with contemporary attributes, where the learning environment is resource challenged, in both the higher education and health sectors. Team-based learning (TBL) has been proposed as a potential instructional method which can retain the educational strengths of PBL, and achieve these in a more efficient way. One of the attractions of TBL is that using fewer tutors solves many resource challenges, including rising student numbers and limited availability of clinicians to teach , 2. WhatPBL is a powerful learning approach offering many benefits including increased acquisition and retention of knowledge, stimulation of problem solving, enhancement of intrinsic subject interest, , 5 deep Team-based learning (TBL), is a relatively new pedagogy to medical education, but has gained popularity within the last 10 years . SimilarTBL, however, is distinctive in both its design and highly structured format. In TBL one tutor facilitates a number of groups simultaneously, in one large room, making it suitable for large class teaching. In PBL, one tutor facilitates one group at a time, in small tutorial rooms. In PBL, no specific nor prescribed pre-reading is usually required. Students prepare as a group, and no formative assessment of learning prior to the tutorial takes place. In TBL, individual pre-reading is required, and to ensure the pre-reading has been completed, both an individual multiple choice test  and a team pre-test (Team Readiness Assurance Test: TRAT), take place at the commencement of class .Although there are many similarities and some differences between PBL and TBL, both rely on constructivist learning theory  to engagWhile TBL is thought to have many similarities to PBL , to dateThe aim of our study was to qualitatively explore our students’ experience of participating in the TBL class format, having previously been exposed to PBL. We use the conceptual framework of constructivist theory to guide our research and present our findings.Sydney Medical School provides a four-year graduate entry program. In years 1 and 2, the curriculum is composed of organ-system based teaching blocks. At the time of the study Sydney Medical School used a two tutorial-based system in the first 2 years of the course for PBLs. This approach to PBL has been modified from the traditional PBL format. Working in collaboration with group members, students analyse a problem of practice, formulate hypothesis, and undertake self-directed learning to try to understand and explain all aspects of the PBL problem. The explanations are encouraged to be in the form of an underlying process, principle, or mechanism. The two 1.5 h tutorials are held on the same day, immediately following each other. The first tutorial being student-led, using the extensive IT materials to support the development of the case. The second tutorial is tutor led. The remainder of the students’ teaching and learning for each week was structured around the problem of the week, consisting of lectures, laboratory practical sessions, and hospital based clinical tutorials.In our study, we piloted two consecutive iterations of TBL, in place of students’ usual PBL sessions towards the end of Year 1 in 2014, during an 8 week Cardiovascular Systems Block. The topics covered in PBL and TBL were:Problem based learning (PBL): 1) Valvular heart disease; 2) Myocardial ischaemia; and 3) Heart failure.Team-based learning (TBL): 1) Congenital heart disease, Down syndrome; and 2) Syncope and arrhythmia/hypertension.In total, there were 298 medical students enrolled in Year 1 at the time of the study (2014). Their PBL groups were permanent for the year. Twenty first year medical students participated in the study. Convenience sampling was used to select two established PBL groups of 10 students. One of the authors (CM), a paediatric respiratory physician, ran two tutorials in PBL format, and then two tutorials in TBL format, across four consecutive weeks.Pre-reading: Prior to class, students were allocated compulsory readings to complete.Readiness Assurance Test process :While the learning outcomes remained the same, two iterations of PBL were converted to TBL format, and were designed to run for 1.5 h each. Teams of five were allocated by the researchers to ensure there was a diverse mix of students in each team. TBL clinical cases included: week 1: Infant with Down Syndrome and congenital heart disease, and Week 2: Young adult with sudden cardiac arrest from prolonged QT interval. We followed a modified TBL structure of:3)Immediate feedback (20 min duration): The correct answers were then released, giving immediate feedback on team and individual responses. Thereafter, the facilitator offered clarification, particularly where teams had experienced difficulty, or disputes.4)Problem solving activities (45 min duration): Students then worked in their teams on their problem-solving activity, utilising the knowledge from the pre-reading. Students had five clinical problems/tasks to work through in their teams. Examples of problems include: “Synthesise your thoughts into a summary statement about the patient, suitable for reporting to an Emergency Department Supervisor”. The final problem/task required student teams to draw a mechanistic flow chart on butcher’s paper using coloured pens.At the beginning of each class, students’ individual knowledge of the pre-reading was assessed. We ran an Individual Readiness Assurance Test (IRAT) (10 min duration), followed by a Team Readiness Assurance Test (TRAT) (10 min duration). The test consisted of 10 Multiple-choice Questions (MCQs), each with one single best answers (SBA). Immediately on completion if the IRAT, the same MCQ test was then repeated by the students as a team (TRAT), with the intent of promoting discussion to establish team consensus.It should be noted that peer evaluation was not part of our modified TBL format.After completion of the two TBL sessions, all participating students were invited to immediately attend one of two focus group sessions (facilitated by AB and TA), with 14/20 (70%) participating. Data were transcribed verbatim. Thematic analysis was used to code and categorise the data into themes. Emergent themes in the dataset resonated closely with key constructs of constructivist theory. Subsequently constructivist theory was used as a conceptual framework to identify recurrent themes . AuthorsEthics approval was obtained from The University of Sydney Human Research Ethics Committee, project no. 2014/687.Results are presented as the emergent prevalent themes, mapped to the conceptual framework of constructivist theory around guided learning, problem solving, collaborative learning and critical reflection.Students perceived that the knowledge and experience of PBL tutors varied greatly. As a result, they felt that their learning was highly dependent on which particular PBL group they had been allocated. Because of the emphasis within PBL on clinical reasoning, students who had had non-clinician facilitators expressed preference for clinicians as facilitators.“We had a physiology PhD student for our first block (of PBL). And we didn’t know because we were starting out as well, but it was a bit of a struggle. None of us knew what we were doing at all. And none of us knew anything about medicine … neither did they. I’d always prefer a clinician. … but there are a lot of PBLs run in a day, so it’s a manpower thing”.Consequently, students preferred the standardisation of the TBL approach, and points of clarification from the tutor were important to their learning, particularly around the depth and breadth of basic science relevant to a clinical problem. Guidance from a clinician facilitator also helped to focus the TBL sessions, with some students feeling that this was a more efficient way to meet their learning goals in relation to a specific problem scenario.“The good thing about the TBLs is that we can make sure that the information we get is correct….PBLs can sometimes go off on a massive tangent that isn’t really relevant to the case. I learnt more in TBL than PBL. It could be effective with a bit more refinement.”Some students felt that within PBL, they weren’t able to develop the depth of knowledge in the basic science required to understand and work effectively on the clinical problem. Within TBL, students appreciated the structure whereby an appropriate emphasis was placed on basic science, in order to apply and link this knowledge to the problem solving activity.“In TBL because we went through the patho-physiology at the beginning with the questions, it made it much easier to link together. I think it went so much faster than our normal mechanism because we had end points that we had to link up”.For other students, the problem solving step within the TBL did not give the same opportunity for discussion on clinical reasoning compared to PBL.“I felt like there were some parts in the PBL that got a lot more focus that we didn’t find so much in the TBL. Like working the management side of things which we didn’t do a great deal on (in TBL).”In TBL, the individual and team tests appeared to be an important influence in ensuring students came to class prepared relative to the rest of their team. Reasons given by the students included not wanting to let their team down, and feeling a sense of friendly competitiveness.“Even though it didn’t matter, us being all competitive people, you were motivated because you didn’t want to completely fluff the test. I think everyone did a bit of preparation”.The team test in TBL promoted competition between teams, and active discussion within teams.“I just took it (TBL) more seriously but I studied for it too. I actually took it more seriously the second week. I mean, last week, I’d say something and if somebody else would say something else, I’m like, okay, we’ll just go with that. But this week, I’m like, oh, wait, let’s think about that. We want to win”.This feature of competitiveness spurring learning in TBL is in direct opposition of PBL goals, which suggest that a lack of competitiveness is more likely to enhance collaborative learning , 17.As in other settings, the size of the year cohort had outgrown the supply of PBL tutors . The sma“I felt more motivated because they’re smaller groups. With a bigger group, you kind of hide under the radar and you don’t really need to do as much preparation. TBL motivates you for a lot more preparation to be honest than PBL”.The small group size increased dialogue and discussion between team members. A sense of joint purpose was fostered, helping to create a relaxed, collegial atmosphere .“I actually think it’s nice that the groups were smaller, with four or five, we were actually able to get dialogue going… not interrupted. With the normal PBLs being bigger, sometimes it’s difficult to get a continuous flow. But with this one we could just talk more. I found communication was definitely good, there wasn’t a problem with TBL”.During PBL, students appreciated the opportunity for the group to work through cases on their own, without direct supervision. Doing so may promote critical reflection, where students are able to reason from their own perspective, and reason with others in order to achieve agreement or confirmation among team members .“There is something to be said about students being unsupervised in the environment where they think through things on their own …. especially in the first year when – some of us has no background in science at all and maybe our analytical minds aren’t as good as some..”In TBL, students felt the individual test and team test at the beginning of class reinforced key concepts for the topic and enabled critical reflection. Learning is supported when there are opportunities to explore and view knowledge in different ways .“You can test your knowledge of reading and studying because we have the test….I liked the questions. It reinforces the concepts for us. And that enables us to go through and think, how does this work, which is good. I think it would be even better if we had more time to do those 10 questions…more time to discuss the questions”.In TBL, an emphasis on active learner involvement, with students tackling problems together, the students’ learning and reflection process was enhanced .“To see the thought process of other people is really useful. You get to see how other people eliminate answers. How other people work through multiple choice questions.”The lens of constructivist learning theory  providedfacilitator with a means to immediately assess students’ knowledge [According to constructivist theory, the focus of the learning should be on the student or learner rather than the teacher. The teacher’s role is that of an expert facilitator, to guide the students in taking an active learning role . By follnowledge  and undenowledge , 25. StuProblem solving activities play a key role in engaging students. They need to be of work related relevance, and challenge prior concepts. Guidance from teachers and team members provides scaffolding for learners to build on prior learning . The pri“go off on a massive tangent.” Students commented on feeling more actively engaged during TBL. This was due to two key elements, including the smaller group size, and the team readiness assurance tests. Completion of TBL tasks, such as tests and problem-solving, required productive team interaction [Students found that while the PBL format encouraged collaborative learning in groups, it was not uncommon for this learning to eraction . Additioeraction , 28. Stueraction , 29.“to see the thought process of other people”, and build one their own understanding. Although reflective practices also occurred through student interaction during PBL sessions, the formal testing procedures in TBLs promoted reflection.Opportunities for critical reflection are needed to allow students to make judgements on required modification to their existing knowledge . In TBL,In this qualitative study, we were able to explore in depth the rich experience of 14 students from a theoretical perspective. The six students who did not participate in the focus group may have had different opinions that were not captured by their peer participants. By timing the focus groups immediately following the TBL, we may have influenced students’ perceptions. If we had timed the focus groups at a later date, their views may have altered.We acknowledge the design and format of both PBL and TBL in this study have been customised to run in a single institution. However, we believe our findings might be helpful to other medical schools investigating the introduction of TBL through pilot studies. We note that we did not provide a control group for the study, which may have provided greater depth to our data and findings.We acknowledge that the facilitator was a senior medical practitioner and academic, with extensive teaching experience. This may have made the TBL experience more positive for our students (whose focus is on medicine) than might be the case if they were taught by a more junior basic science staff member.Our study findings indicate that wider scale implementation of TBL, with further modifications is needed before a decision can be made on final changes to teaching methods. Further modifications would include: extended duration of TBL to allow more time for clinical reasoning; and prompts to facilitate clinical reasoning during the TBLs.Both TBL and PBL offer effective teaching methods that are based on constructivist learning theory. Our students found their learning experience in TBL to be qualitatively different to their previous experience in PBL, identifying advantages and disadvantages to both. Although the use of TBL required an instructional approach, needing direction from the tutor, it remained student-centred, generating a range of positive outcomes. In particular, TBL resulted in better preparation, immediate feedback on progress, and smaller group size. The findings from our study suggest a hybrid approach that utilises the strengths of both TBL and PBL strategies needs to be considered for wide scale implementation.


Hockey is a complex and multifaceted game, yet many of the statistical tools used to evaluate performance are univariate. To garner a better understanding of hockey’s multifaceted nature, two structural equation models (SEMs) assessing the interrelations between offense, defense, and possession were built from three seasons of NHL data. Overall, it was found that the concepts of offense, defense, and possession are best understood via a small constellation of measured variables, and that offense mediates the relationship between possession and defense such that higher levels of offense leads to poorer defensive performance. These findings are discussed within the context of ranking player performance. Ice-hockey (referred to as hockey for the remaining text) is a complex, fast-paced, team versus team sport whereby each team tries to shoot a small puck into a net more times than their opponent . Teams are allowed to have six players on the ice at any given time , with the game being played in three, 20 minute, stop-time periods. Stoppages in play occur when (i) a rule is broken, (ii) the goaltender covers the puck, (iii) the puck goes out the defined playing area, or (iv) a goal is scored. Like other professional sports, there are different “levels” at which the game is played, the highest being the National Hockey League (NHL), which involves 30 teams spread across Canada and the United States.Since Bill James’ seminal work on sabermetrics , there has been a growing interest in the empirical analysis of sport –3. TheseRecent efforts in this regard have brought about a wide range of descriptive statistics, with the entire corpus being referred to as “advanced statistics” by the hockey community. Fortunately, the majority of these advanced statistics fit within a hierarchical structure such that upward movement produces an increase in specificity, with this specificity being geared towards capturing the complex, interactive effects prevalent within the game .At the most fundamental level sits raw performance metrics such as goals, assists, shots, and-so-forth. Although the number and variety of advanced statistics at this level is vast, this paper focuses on a small number of metrics: corsi, points, goals for, goals against, assists, and faceoff location.Defintition 1. Corsi is the total number of shots that (i) were on net, (ii) missed the net, or (iii) were blocked on route to the net.Corsi values can be broken down into a number of different metrics, such as corsi for (corsi events against the opposing team), corsi against (corsi events against the player’s team), corsi for percentage (corsi for divided by the sum of corsi for and corsi against). Further, each of these metrics can be broken down according to a variety of different grouping values . Finally, corsi is generally measured at the linemate level as individual corsi metrics are captured by other measures  Thus, anytime a corsi event occurs, that event is recorded for every player on the ice. Unfortunately, there exists no standardized symboling system for corsi (or any other advanced statistic) within the academic literature, so I will adopt the following:Time on ice = TOICorsi = CfCorsi for = CaCorsi against = Cp = Cf/(Cf + Ca)Corsi for percent = Cf/TOI)Corsi for per 60 = Ca/TOI)Corsi against per 60 = Defintition 2. Goals are the number of times the puck is shot past the goalie and into the net.As is the case with corsi, goals can be broken down by metric and grouping:Goals = GiIndividual goals for = GfGoals for while on the ice  = GaGoals against WOI = Goals for WOI per 60 = Goals against WOI per 60 = Individual goals for per 60 = Defintition 3. An assist on a goal is awarded to a maximum of two players on the scoring team, not including the goal scorer, that touched the puck in a way that helped facilitate the goal, be it by shooting, passing, or deflecting the puck.Assists = AiIndividual assists = Individual assists per 60 = Defintition 4. Points are the number of goals plus the number of assists.Points = PiIndividual points = Individual points per 60 = Cp relative to the rest of their team, all one would have to do is take that player’s Cp and subtract the Cp of the team when the player is not on the ice.The focus at this level is on taking raw metrics and situating them within the context of the entire team . For exaDefintition 5. Off-ice metrics for a player are the metrics posted by the team when the player is not on the ice during games the player participates in.Defintition 6. Relative to team metrics are on-ice metrics minus off-ice metrics.τ before the raw metric:I have elected to signal these metrics by placing τCpCorsi for percent relative to team = Corsi for per 60 relative to team = Corsi against per 60 relative to team = Goals for per 60 relative to team = Goals against per 60 relative to team = τ-metric, thus τ-metrics typically make use of raw metrics involving percentages or standardized groupings .It should be noted that not every raw metric has an associated τ-metrics is to get an idea of whether a player helps or hinders their team’s overall performance. If a player has a positive Overall, the goal of τ-metrics are, it is also helpful to know how a player performs relative to their linemates. For example, if we wanted to see how a player’s not on the ice with the player. Next, we weigh that did spend on the ice with the player. Once we have weighted values for each linemate, we simply take the average and subtract it from the player’s As beneficial as r’s Cf60 .Defintition 7. Relative to linemate metrics are a player’s raw metric, minus the weighted average of their linemates’ raw metric while playing on a different line.and linemate interaction, if we take out linemate performance while playing on a different line, we are, in effect, taking out the contribution of linemates to the player’s performance. Otherwise stated: if, on average, a player’s linemates perform better when they are on a different line, then that player is, on average, worse than their linemates and drags down their linemates performance. Obviously this is not an idea formulation as the interactive effects of linemates are more than the sum of their individual parts, but it does provide us with a rough estimate.This approach is needed to strip away as much of the interaction between players as possible. That is, individual player performance is highly dependent on linemate performance; thus, the thinking goes, because the player’s δ.I have elected to indicate relative to linemate metrics by preceding the raw metric with δCpCorsi for percent relative to linemates = Corsi for per 60 relative to linemates = Corsi against per 60 relative to linemates = Goals for per 60 relative to linemates = Goals against per 60 relative to linemates = As previously noted, hockey has lagged behind other sports with respect to data analysis; however, some interesting results have still been produced.For example, Macdonald  used a vIn a similar vein, Thomas and colleagues  modeled Gf − Ga) by controlling for the contributions of teammates, and found that a relatively narrow band of players had a significant effect on goal scoring, be it positive or negative [These findings are paralleled by the work of Gramacy and colleagues , who buinegative .The idea of quantifying individual performance was taken a step further by Schuckers and Curro’s Total Hockey Rating (THoR), which is based on (i) every non-shooting on-ice event for a player, (ii) whether the player had home-ice advantage, (iii) what zone the play started in, and (iv) everyone else that was on the ice with the player . The modShifting away from individual performance, work by Roith and Magel  demonstrAdditional efforts have been made to classify NHL players based on their style of play , 16, as Structural equation modeling (SEM) is a relatively new, and increasingly popular, statistical technique designed to address the issues outlined above by combining factor analysis with tools such as regression and analysis of variance .At its core, a SEM consists of two categories of variables (measured and latent) and a path diagram that specifies the relationships between these variables –21. HereOne significant benefit of using SEM to analyze hockey data is SEM’s ability to deal with multicollinearity. As discussed by MacDonald  and GramSimilarly, SEM’s use of latent variables and its ability to easily specify multivariate models has made it a popular tool in fields that infer characteristics based on multiple measured variables . Given tOverall, the goal of SEM is to specify a model whose estimated means and covariances (referred to as parameter estimates) fit the observed data. If a model produces parameter estimates that closely match the data, that model is said to be accepted; if the parameter estimates do not match the data, then the model is said to be rejected.The univariate nature of prior research runs counter to the multivariate nature of hockey; offense cannot be fully captured by a single measure such as goals or points, nor can possession be fully captured by corsi for percentage, nor defense by goals against. Moreover, the concepts of offense, defense, and possession are best described by a constellation of measured variables, thus it is beneficial if assessments of performance include enough measured variables to sufficiently capture the concepts in question. With this in mind, the aim of this research is to identify a system of regressions and a constellation of measured variables that fit both the data and prior research. Extending the work of Macdonald  and Thomwww.puckalytics.com, has since shut down as the website owner has been hired by an NHL team. Additional repositories can be found here: [M = 843.98, SD = 334.83).To fit the model, I make use of three seasons worth of NHL data (2012/2013 to 2014/2015) retrieved from a well-known public repository compiled from official game reports supplied by the NHL . I limiIn an attempt to build a more complete picture of how popular advanced statistics related to each other, I built two SEMs with the same structural model, but differing measurement models.OZFOp), and defensive zone faceoff percentage . OZFOp and DZFOp were selected on the grounds that faceoff metrics have been linked to both team and player performance [OZFOp was placed under possession as it was found to produce a better model fit than when under offense, with DZFOp being placed under defense as it produced a better model fit than when under possession. Although seemingly contradictory (would faceoff location not be an indicator of possession?), this phenomenon can possibly be explained by icings, and how the team that ices the puck is not allowed to substitute players. This can lead to tired skaters who may be more likely to make a defensive mistake that leads to a goal against, thus placing DZFOp under defense, as opposed to possession.The measurement model of the first SEM can be seen in formance , 14. OZFpossession to offense, possession to defense, and from offense to defense. Further, all latent variables have disturbances to account for any unspecified predictors. These disturbances are uncorrelated under the premise that defense disturbances can largely be attributed to goaltender skill, which has no impact on offense; and that offense disturbances can largely be attributed to individual skills such as shooting percentage , which have no bearing on defense. Moreover, possession disturbances can largely be attributed to metrics such as offensive zone faceoff win percentage and offensive zone entry metrics, which have no bearing on the skill metrics of offense and defense. Finally, disturbances are not removed under the second measurement model as the additional measured variables do not comprise an exhaustive list of all the measured variables that comprise each latent variable.The structural model  has pathThe theory behind each SEM is simple: (i) if a team/line/player spends more time in possession of the puck, then they are not only more likely to score more goals/points, but also have fewer goals scored against them; and (ii) players/lines with a high level of offensive output are more likely to have goals scored against them (possibly) due to missed defensive coverages brought about by an overemphasis on offense.All analyses were conducted in R, and made use of the lavaan package for structural equation modeling (using a maximum likelihood estimator) .DZFOp (5.14), which suggests a large number of players’ scores for DZFOp clustered about the mean. Overall, the high level of univariate normality exhibited by the data means it is unlikely the models will produce biased parameter estimates that deviate from observed scores.Descriptives statistics for measured variables can be seen in N > 600), such as in this study (N = 678) [N = 300 produce biased parameter estimates that lead to greater rates of model rejection, and that non-normal samples should be N > 600 to ensure unbiased parameter estimates.Mardia’s multivariate normality tests revealed that none of our latent variables were multivariate normal . HoweverN = 678) , 28, 29.N = 678)  point ouN = 678) . FurtherN = 678)  found thN = 678) , who fouN = 678) , who fouN = 678)  points oAll that said, a visual inspection of the data Figs –7 suggesoffense, A model is of little use if its parameters do not have at least one unique solution , thus we need to make sure both the measurement and path models are identifiable . As per s Tables –8. Similpossession and offense were moderate, with weak to absent correlations everywhere else, the exception being DZFOp, which exhibited a (mostly) moderate negative correlation with all the measured variables.I first performed a visual inspection of the correlations between all relevant metrics . As expeβ) and unstandardized (B) regression weights in possession was negatively related to defense and positively related to offense, and that offense was positively related to defense. Moreover, with both measurement models, the effect between possession and defense was weakened when offense was introduced as a mediator .χ2 was observed. However, in line with [χ2 metric was ignored in favor of the standardized root mean square residual (SRMR), the Tucker-Lewis index (TLI), and comparative fit index (CFI). The SRMR was selected as the indicator of absolute model fit, and is simply the standardize difference between observed and predicted correlations  [Assessments of model fit can be seen in ine with , 36, theOZFOp and DZFOp , which is approximately one half of a standard deviation in observed Cp scores.Here, the model provided accurate offense, MAE and RMSE values for With respect to Defense indicators followed a similar prediction pattern as possession and offense indicators, with Finally, although correlations between predicted values and observed values were high across all measured variables, To examine the stability of performance predictions across a longer time-period, parameter estimates from model 1 were used to generate predicted values for the 2010/2011 and 2016/2017 NHL seasons  we want to predict.  best made with the measured variables themselves).overall performance scores.Just as a person’s intelligence is comprised of scores on various abstract concepts , which are themselves comprised of scores on a variety of measured variables, so-to is a hockey player’s overall performance. That is, a player’s overall performance is simply a composition of their scores on latent variables. To this end, latent variable factor scores were obtained for players who played at least half of the 2016/2017 season (41 games), and were combined to generate possession , yet Trocheck had an offense score of 0.23, whereas Krejci had a score of 0.11. This is largely because Trocheck managed to generate the same output while playing on a substantially worse team.e scores  identifidefense scores reflect goals against, smaller values indicate better performance  or defensemen . Instead, the rankings primarily consist of “utility” forwards and defensemen, which is to be expected given the inverse relationship between offense and defense.Because formance . Here, doverall score exists as some combination of possession, offense, and defense; how these three scores are combined, however, depends on how much emphasis a person places in each of the above factors; if a person believes offense is more important than defense, then they will assign more weight to those scores. Regardless of how this emphasis is distributed, we must scale possession scores down by a factor of 10. This is because possession factor scores take into consideration Cp scores, which are an order of magnitude larger than all other measured variables, thus leading to possession scores being an order of magnitude larger than offense and defense scores. If we do not perform this re-scaling, then overall scores will be almost entirely determined by possession scores. Moreover, because smaller defense scores indicate superior performance, defense scores should be subtracted, not added, to possession and offense scores. Otherwise stated, to generate overall scores, we decided if, and by how much, we want to weigh each of the latent variables, then compute overall scores by scaling possession scores down by a factor of 10, adding that value to offense scores, then subtracting defense scores from that new value.As stated earlier, a player’s overall rankings, two formulations were constructed  gives a more accurate depiction of player performance. Here, Connor McDavid, the leagues leading scorer and Hart Trophy winner , tops the list, with Mathew Tkachuk falling back two spots to number three. Moreover, the list is comprised largely of forwards, with the top defenseman being Brent Burns, the James Norris Memorial Trophy winner (awarded to the league’s best defenseman).Given how much harder it is to score goals than prevent them, this offense mediates the relationship between possession and defense, and that this mediation occurs under multiple measurement models. One possible explanation for this relationship is that players who score lots of points are more likely to “cheat” for offense than their low scoring counterparts, which leads them to neglect defensive responsibilities that would otherwise have prevented goal(s) against. This theory is tangentially supported by zone entry research suggesting that controlled entries into the offensive zone produce more goals than attacking after the puck has been shot into the offensive zone, and that controlled zone entries are thought to be a higher risk play as a turn-over at the offensive blueline can often lead to a dangerous scoring chance against [Paralleling Thomas and colleagues’  work dem against . Thus, ioffense, but it is an interesting and important avenue for future research.Another possible explanation rests in the idea that scoring points at the NHL level is incredibly difficult, and players who manage to do so have focused on developing their offensive skills to the detriment of their defensive skills. This, in turn, makes them less capable defensively, which leads to more goals against. From this data it is impossible to say for certain what drives the mediating effect of Cp in model 1 ).In having identified a model that conveys the multivariate nature of hockey, and that is applicable across multiple seasons, we are able to not only generate factor scores for latent variables, but also combine these scores into an S1 FileShould interested parties want the corresponding R code, the author is happy to provided in upon request.(XLSX)Click here for additional data file.


Developmental biology (including embryology) is proposed as "the stem cell of biological disciplines.” Genetics, cell biology, oncology, immunology, evolutionary mechanisms, neurobiology, and systems biology each has its ancestry in developmental biology. Moreover, developmental biology continues to roll on, budding off more disciplines, while retaining its own identity. While its descendant disciplines differentiate into sciences with a restricted set of paradigms, examples, and techniques, developmental biology remains vigorous, pluripotent, and relatively undifferentiated. In many disciplines, especially in evolutionary biology and oncology, the developmental perspective is being reasserted as an important research program. We were finishing dinner at a conference on evolutionary developmental biology when a graduate student asked me to explain some comments I’d made during a question and answer session. I had disagreed with a colleague’s reliance on citation analysis to present a history of evolutionary developmental biology. Citation lists are political documents, I had argued. Citations don’t reveal whether a paper had influenced the author, or even whether the author had read it. Furthermore, a history of a new field should explain why the field arose. It might even have a mythos, a narrative theme for its origin story.The student asked if my account of the history of evolutionary developmental biology had an underlying narrative and, if so, what it was. I told him something like, “Yes. If you analyze my accounts, you’ll find that there is an underlying narrative, and that narrative is ‘the return of the rightful sovereign.’ Development was originally seen as the motor of evolution, and the principal way of explaining evolution was through embryology. In fact, in the late 1800s, the word ‘evolution’ could mean either phylogenetic or embryological development. But genetics arose out of embryology, and eventually, evolution came to be seen as a proper subset of population genetics. Genetics displaced development as the way to study evolution. In my narrative, evo-devo represents the return of developmental biology to its rightful place as the means to study evolution.”Robin Hood, in which the captured monk dramatically sheds his clerical garb to reveal himself as King Richard, returned to England to correct John’s injustices?”Sensing he didn’t get the connection, I continued. “The return of the rightful sovereign. Remember Errol Flynn’s Game of Thrones,” I hazarded.My dated allusion was not getting through, either. “Game of Thrones!”“Yes!” he exclaimed, “I get it. Evo-Devo and As I recalled my version of developmental biology’s origin story, I pondered a larger question, which others had also noted : Why andAs should be clear by now, I have indeed wondered why developmental biology has been overlooked and am playing with a hypothesis to explain why. I propose that developmental biology  has been the stem cell of biological disciplines. It is not a “differentiated” discipline, but the pluripotent discipline that generates disciplines like genetics and immunology, all the while retaining its own identity.Developmental Biology. It was named again in the 1970s, for the annual series, Current Topics in Developmental Biology, where it was seen as the molecular approach to embryology. In both cases, “developmental biology” was viewed as the modernization and extension of embryology [So, let us begin with the cell theory. In the mid-1800s, the study of embryos gave rise to various theories of cell formation. Schleiden, Schwann, and Remak formed their cell theories to answer the question of how multicellular embryos emerged, and thus gave rise to the discipline of cytology/cell biology –6. TodayShortly thereafter, the gene theory was constructed by embryologists who had been embroiled in debates over what part of the embryo—the nucleus or the cytoplasm—controlled development. In the early 1900s, embryologists Theodor Boveri and E. B. Wilson believed that the nucleus, especially the nuclear chromosomes, carried the instructions for organismal development. In contrast, embryologist Thomas Hunt Morgan (who had written a monograph on the embryology of the frog egg) favored the cytoplasm  inadvertAs a student of both biology and religion in college, it struck me how the rise and separation of genetics from embryology, and the disparagement of the parent discipline by some of the acolytes of the new discipline, echoed the supersessionist rhetoric of Christianity as it separated from Judaism. Even more interestingly, some of the founders and critics of early genetics seemed to think so, too . Morgan Vestiges of the Natural History of Creation was the first book “to link a developmental view of the world with evolution” [As English replaced German as the language of science, so genetics replaced physiology and development, including theories of development as the motor of evolution. Early evolutionary theories, such as those of Robert Chambers and Charles Darwin’s grandfather, Erasmus, were based on embryonic development, especially developmental morphology. Chamber’s sensational and widely selling olution” . Using volution”  argued tolution” . He alsoolution” –20. Whenolution”  made embolution” ,23. Indeolution” , the worThat view shifted with the advent of genetics. Rather than viewing evolutionary biology as the study of macroevolution, Morgan ,25,26 woNeurobiology similarly has an embryological pedigree, and in the early 1900s, one of its biggest concerns was whether the axon was really a cellular process that extended meters in the body. Ross Granville Harrison’s inaugural tissue culture experiments  solved tOn the Origin of Species was published, Rudolf Virchow’s classic volume, Cellular Pathology, drew on embryology to explain pathology. Cancers, he argued, should be studied as errors of development because tumors appeared “by the same law, which regulated embryonic development” [In 1859, the same year Darwin’s lopment” . In the lopment”  claimed lopment” ,34. Scielopment” .Yet, genetics soon assumed dominance over the field of cancer research just as it had with evolutionary biology (whose paradigms cancer biologists often propose for their own field). The founding document of the genetic (somatic mutation) theory of cancer appears to be that of Boveri . Boveri Having generated cell biology, immunology, genetics, neurobiology, and oncology, developmental biology still seems to be budding off new disciplines. Evolutionary developmental biology sees evolution as Huxley did, as changes in development  and focuses on the arrival of the fittest. Ecological developmental biology sees the environment as having instructive as well as permissive agency in normal development. Systems biology, which began with embryologically oriented philosophers such as Woodger and von Bertalanffy –47, atteAnd other new disciplines are struggling to form an identity separate from their developmental parent discipline. Stem cell biology has its own meetings, its own journals, and its own professional societies, different from those of developmental biology. When Irving Weismann, one of the founders of the International Society for Stem Cell Research, became president of that organization, he threw down the gauntlet to developmental biology, saying ,“We are a field, a discipline, and an entire branch of science that brings new ideas, experiments, concepts, and medical translation. Like anything new, we are a threat to the established order, and at every kind of educational and research institution, to thrive, we must be recognized as entities, not as divisions of old entities.”Stem Cell Reports are papers that would find a home in journals of developmental biology. At the moment, stem cell biology is a political, rather than an intellectual, bud from developmental biology, and it is performing important services in creating science-based educational accessibility and political guidelines, which the developmental biology societies have not done. Whether it becomes more than a medical aspect of developmental biology remains to be seen.But it is not yet a truly independent field, as it has yet to propose anything different from developmental biology. All the articles in There are three main messages of this essay. The first is that developmental biology is not a confined, specified discipline—such as genetics, cell biology, immunology, oncology, neurobiology, and so forth. Developmental biology is not confined to any level of organization . It can be studied in any species, organ system, or biome. Developmental biology remains pluripotent. The descendants of developmental biology—cell biology, genetics, immunology, neurobiology—are more differentiated and their potency much more restricted. They have boundaries. Surely, developmental biology has its own set of questions, perhaps the best questions of any science—How does the brain form? How do the bones of the arms become different from the bones of the legs, and why can’t we regenerate them like salamanders do? How do testes usually originate in people with a Y chromosome and ovaries in people with two X chromosomes? (And these are only a few of the questions in humans)—and it regenerates itself constantly as new techniques and hypotheses become available. Indeed, developmental biology has been called an “erotetic science,” differing from most other sciences in that it is driven by questions, not theories . Thus, dThe second message is that developmental biology remains a vital generative science. The induced pluripotential stem cells (iPSCs) are derived from the principles and discoveries of developmental biologists, as are the human beta-pancreatic cells now in clinical trials. The neural embryoids derived from such cells are now being used to study the mechanisms by which the Zika virus causes microcephaly. The 3D structure of chromatin and its remodeling during early mammalian development is becoming known, as are the mechanisms of X-chromosome inactivation. Developmental biology is also being expanded by identifying the interactions of the zygote-derived cells with those of symbiotic microbes to form organ gut, capillary, and immune cells. We are discovering how the turtle gets its shell and how the butterfly wing develops structural colors. We are in a new golden age of developmental biology.The third message of this essay is that in the 21st century, many of the disciplines that had come from developmental biology are returning to a developmental framework, even if they don’t call it “developmental biology.” This is probably because developmental biology has always been a science about relationships in which context is critical , and the


Many women in the UK stop breastfeeding before they would like to, and earlier than is recommended by the World Health Organization (WHO). Given the potential health benefits for mother and baby, new ways of supporting women to breastfeed for longer are required. The purpose of this study was to develop and characterise a novel Motivational Interviewing (MI) informed breastfeeding peer-support intervention.n = 14), and focus groups with mothers (n = 14), fathers (n = 3), and breastfeeding peer-supporters (n = 15) were carried out to understand experiences of breastfeeding peer-support and identify intervention options. Data were audio-recorded, transcribed, and analysed thematically. Consultation took place with a combined professional and lay Stakeholder Group (n = 23). The Behaviour Change Wheel (BCW) guided intervention development process used the findings of the qualitative research and stakeholder consultation, alongside evidence from existing literature, to identify: the target behaviour to be changed; sources of this behaviour based on the Capability, Opportunity and Motivation (COM-B) model; intervention functions that could alter this behaviour; and; mode of delivery for the intervention. Behaviour change techniques included in the intervention were categorised using the Behaviour Change Technique Taxonomy Version 1 (BCTTv1).Qualitative interviews with health professionals and service providers  included social support, problem solving, and goal setting. The intervention included important inter-personal relational features , and the BCTTv1 needed adaptation to incorporate this.The MI-informed breastfeeding peer-support intervention developed using this systematic and user-informed approach has a clear theoretical basis and well-described behaviour change techniques. The process described could be useful in developing other complex interventions that incorporate peer-support and/or MI.The online version of this article (10.1186/s12884-018-1725-1) contains supplementary material, which is available to authorized users. Extending the duration of breastfeeding remains a challenge, particularly in high-income countries and where there is a formula feeding culture –4. Many Breastfeeding peer-support is an approach where support is provided to mothers by mothers who have personal experience of breastfeeding. Peers may be perceived to be more approachable than health professionals in some settings, as they have direct experience of the challenges of breastfeeding within a social context where it is not the norm, and can provide role-models that mothers can relate to , 9. BreaA realist review  identifiOne approach that has been successfully used in peer-led interventions in other areas of healthcare is Motivational Interviewing (MI) . MI is aC), social and physical opportunity (O), and automatic and reflective motivation (M) can influence behaviour Pregnant women and mothers tended to place a greater emphasis on modelling and social support, whereas fathers and health professionals focused more on training.“I think the social aspect is really important, I think it’s the main key, because as a breastfeeder you feel quite isolated, whether it’s within your family, within your friends, so belonging to a breastfeeding community gives you the encouragement to keep breastfeeding and to keep following what you want to do. I think without this community most of us probably wouldn’t have got anywhere as far on our own.”“And quite often you’ll have mothers being told by relatives and friends, “Are you feeding again, he’s hungry again, you only just fed him”, you know, this type of thing, and of course the mothers get very demoralised then, and they start questioning the breastfeeding, they start thinking that you know, they’re not producing enough milk and all this sort of stuff. It takes quite a strong willed woman, and if she’s a young girl...”There was a consensus across the groups that persuasion and coercion were not acceptable in the context of breastfeeding peer-support; pressurising mothers was contrary to the expressed needs of women and was viewed as being counter-productive. Mothers and fathers expressed a preference for a supportive, collaborative relationship, and valued positivity and encouragement. They expressed a preference for neutral and realistic information, rather than a persuasive approach that emphasised the benefits of breastfeeding.For one of the service managers, peer-support was seen as being particularly valuable in counteracting negative attitudes in social contexts where breastfeeding is not the norm:“You don't want that person preaching to you saying, oh, I breastfed my child until 18 months or whatever. You don't want that. You just want ‘I'm here to help”.All participant groups viewed engaging with and activating mothers’ own support networks, both in terms of their social networks and other health care and community services that might be available to them, as an important element of peer-support. Peer-supporters acknowledged the need to engage with fathers in achieving this:“Maybe we need more support for the fathers then, so that they can provide that support to their partners in the early hours, you know when they can’t get to the peer supporter, call the fathers to have enough support and help them through it.”From the parents’ perspective, another important aspect of the peer-supporters’ role was to link mothers with other services, including health professionals and local groups.Four core themes were identified in relation to implementation of the intervention (i.e. ‘mode of delivery’); the timing and frequency of contact between peer-supporters and mothers, resources, boundaries, and training and support for peer-supporters.In all participant groups, people felt that having initial contact between peer-supporters and mothers during the antenatal period would be beneficial, mainly in terms of building up a rapport. During the postnatal period, early support was often viewed as being important:“It only takes one little comment in an early stage to put the seed of doubt in somebody's mind and they think, ‘oh, I'm not doing this right.’ ‘I'm not making enough milk’ and that's the whole breastfeeding journey come to an end because of somebody's attitude early on, the throw away comment.”Mothers, fathers and peer-supporters generally felt that peer-support should be able to continue in a flexible way until mothers had stopped breastfeeding. Peer-supporters felt that ending the intervention should be handled sensitively so that mothers didn’t ‘just feel dumped’.Across all participant groups, there was an acknowledgement that maternity services were very busy and over-stretched, and there was a perception that peer-supporters would have more time to spend with mothers than health professionals, particularly during the critical early stages of breastfeeding. Many peer-supporters felt that post-natal support would ideally start while mothers were in hospital for this reason. Although the clinical context was not known, one of the mothers spoke about her experience of being on a busy post-natal ward in negative terms:“There was a lady opposite me absolutely sobbing her heart out because the midwife just wouldn't help her. You have to give her a bottle, you have to give her a bottle. She said, I don't want to give her a bottle, I want to feed her.”Health professionals had more mixed views about providing breastfeeding peer-support in the hospital environment; some felt the hospital environment was too busy and pressured already and that ‘another body’ would not be helpful.Employing peer-supporters, as opposed to a voluntary service, was generally seen as being a positive thing in making the work more viable for local women and providing more of a professional relationship between peer-supporters and local healthcare services. However, there were some concerns about diverting limited funding away from existing services.Peer-supporters felt it was important for there to be boundaries around contact with mothers, particularly in terms of working hours and availability. This was a complex issue, with tension between wanting to provide flexible and responsive support, and needing to make the role practical and manageable. Mothers and health professionals also acknowledged the importance of setting boundaries around the peer-supporters’ role. Good communication between peer-supporters and health professionals, clear roles and responsibilities, good training and support, and familiarity with the local service context were viewed as being important in maintaining boundaries and facilitating integration with local services.looking at the positives not the negatives’, and could ‘draw out people's personal reasons and what they might be worried about’. A health visitor said that ‘I get the impression it’s a very gentle approach, going with the flow type of thing’.The health professionals, who felt that training needed to be robust, discussed training for peer-supporters most extensively. When we asked health professionals what they thought of using an MI-informed approach in breastfeeding peer-support, they were generally familiar with the basic principles of MI and felt that it would be useful, particularly in terms of developing communication and listening skills. They felt that MI would reinforce mothers’ confidence, help with ‘at least one antenatal contact with pregnant women to enable information exchange and build rapport, make contact withmothers in the first few days after birth (to include around 72 h when babies are routinely weighed), provide flexible on-going support in the postnatal period to meet individual mothers’ needs, and the peer-supporters should end the intervention in a way that provides affirmation of the mother’s efforts and enables her to access other sources of support in the longer term .Peer-supporters should: make Boundaries around the peer-supporters’ role should be: clearly set from the outset; generated by an external party to provide consistency and ensure safety; acknowledge the limits of peer-supporters’ knowledge and skills, and; be discussed and reflected on during supervision sessions.The intervention should focus on enabling mothers to cope outside of the peer-supporters’ working hours by signposting to other services and activating their social networks. For example, by including partners or other family members in discussions if they are present when peer-supporters visit mothers.Responsibility for peer-supporter training needs to be clear, and appropriately resourced. Health professionals felt that training of peer-supporters was usually a community based activity and typically fell within the remit of health visitors.Following initial training, peer-supporters need support from midwives and health visitors to help with their practice and to deal with any issues or questions that they are uncertain about. Peer-supporters should be linked up with each other, e.g. by having a meeting once a month where they can share experiences and good practice and through social media groups, such as closed Facebook groups.Key themes from a realist review carried out by our team  and otheThe Stakeholder Group developed ‘principles of good practice’ for the delivery of MI based breastfeeding peer-support, stating that peer-supporters should be ‘supportive’, ‘positive’, ‘non-judgemental’, ‘approachable’, ‘honest’, ‘down to earth’, and ‘a good listener’. The intervention name ‘Mam-Kind’ was developed in conjunction with the stakeholder group and the peer-supporters who were part of the informal closed Facebook group set up for this study. The features of the intervention name that were important to stakeholders were that was centred on the mother, emphasised kindness, and did not include direct reference to breasts, breastfeeding, or breastmilk which were perceived to be off-putting for women in cultural contexts where breastfeeding was not the social norm.We developed the logic model for the intervention based on the results from our qualitative research and discussions with the Stakeholder Group Fig. .Fig. 2MIWe produced a description of the content and timing of intervention sessions during the antenatal and postnatal periods and classified the behaviour change techniques included using the BCTTv1 Table .Table 3CThe intervention was designed to allow sufficient flexibility to meet individual mothers’ needs, for it to be practical to deliver it, and for the behaviour change techniques included to be clearly defined and categorised. Having characterised the core functions and content of the intervention, we developed training materials for use with peer-supporters to provide them with the skills and knowledge required (available from authors on request).We used a systematic and user-informed approach, guided by the Behaviour Change Wheel (BCW), to develop and characterise a novel MI-based peer-support intervention to support breastfeeding maintenance: the Mam-Kind intervention. The intervention developed in this study has important features for effectiveness and successful implementation that have been identified in previous literature, including being pro-active, intensive, mother-centred, and having a clear theoretical basis , 17, 18.The BCW is an extensive but not exhaustive model . MI is aThe ethos of MI focuses on working with people, rather than doing things to them, to elicit change. For example, categories of the BCTTv1 related to the provision of information, but not to eliciting information from people thus drawing on their own knowledge and experiences. Using a MI informed approach, a peer-supporter would seek to guide a mother in reflecting on her breastfeeding goals and outcomes, using open questions and simple and complex reflections to explore her own beliefs, motivations, and ambivalence, which broadly fits within the ‘review behavioural goals’ and ‘review behavioural outcomes’ BCTT v1 categories. ‘Commitment’ is described in the BCTTv1 as asking a person to explicitly affirm or reaffirm their commitment to behaviour change. In a MI informed intervention, the approach is less directive, and this is affirmation of commitment is likely to come from the mother herself. We categorised affirmation as ‘social reward’ using the BCTTv1, as it provides positive reinforcement of the mother’s efforts. We categorised conveying empathy and emphasising autonomy as ‘social support ’ as these were not explicitly described in the BCTTv1.We worked with the Stakeholder Group to develop a set of ‘guiding principles’ for our intervention to be used alongside the technical behaviour change techniques categorised using the BCTTv1, which allowed us to describe factors relating to its underlying ethos and inter-personal style. Our study has provided stakeholder support for a guiding principle that breastfeeding peer-support should focus on empowering mothers, supporting them through the breastfeeding journey, affirming their efforts and respecting their choices. This study indicated that very directive approaches to increasing breastfeeding maintenance and those that reduce the autonomy/control are likely to have low acceptability to mothers. These important, subjectively experienced factors apply to many types of intervention and can be challenging to objectively measure and assess, but need to be given sufficient attention in future iterations of the BCTTv1.Limitations of the study are that a small number of local sites were used for the in-depth qualitative and stakeholder work . The MI-informed breastfeeding peer-support intervention that we have developed is intensive and would require more resources to deliver than low intensity/group based peer-support. Providing the feasibility and acceptability of the intervention can be demonstrated, evaluating the cost-effectiveness, as well as clinical effectiveness, of the intervention will be essential in future studies.Using a systematic and user-informed process, guided by the BCW, we have developed and characterised a novel MI informed peer-support intervention that can be tested for feasibility of delivery. The intervention development process described is likely to be useful in developing other interventions that use peer-support and/or MI-informed approaches, but the BCTTv1 system requires some adaptation to incorporate important inter-personal relational aspects of such interventions.Additional file 1:Interview topic guide: development focus groups with mums . (DOCX 26 kb)Additional file 2:Interview topic guide: Development focus groups with dads . (DOCX 25 kb)Additional file 3:Interview topic guide: health professionals and service managers. (DOCX 477 kb)Additional file 4:Interview topic guide: focus groups with peer supporters. (DOCX 26 kb)


People seeking care for substance use (PSCSU) experience deep social and health inequities. Harm reduction can be a moral imperative to approach these persons. The purpose of this study was to explore relationships among users, health care providers, relatives, and society regarding harm reduction in mental health care, using a trust approach rooted in feminist ethics.A qualitative study was conducted in a mental health service for PSCSU, and included fifteen participants who were health care providers, users, and their relatives. Individual in-depth and group interviews, participant observation, and a review of patients’ records and service reports were conducted.Three nested levels of (dis)trust were identified: (dis)trust in the treatment, (dis)trust in the user, and self-(dis)trust of the user, revealing the interconnections among different layers of trust. (Dis)trust at each level can amplify or decrease the potential for a positive therapeutic response in users, their relatives’ support, and how professionals act and build innovations in care. Distrust was more abundant than trust in participants’ reports, revealing the fragility of trust and the focus on abstinence within this setting.The mismatch between wants and needs of users and the expectations and requirements of a society and mental health care system based on a logic of “fixing” has contributed to distrust and stigma. Therefore, we recommend policies that increase the investment in harm reduction education and practice that target service providers, PSCSU, and society to change the context of distrust identified. People seeking care for substance use (PSCSU) experience deep social and health inequities. The perspective of harm reduction can be viewed as an ethical commitment and a moral imperative to approach these persons in such a way that “they are not forced to change and their choices are respected while trust and opportunities to access health care are preserved” In the context of ethical dimensions of care for PSCSU, we highlight Baier’s 1985) philosophical work that describes trust as a “reliance on others’ competence and willingness to look after, rather than harm, things one cares about which are entrusted to their care” p. 259) . Additio59 . Addi85 philosBuilding on the work of Baier  , 13 and In this study, we explored how a trust approach could help to clarify relationships among users, HCP, relatives, and society with respect to harm reduction in a mental health care context for PSCSU of alcohol, crack, and other drugs. Specifically, our research questions were the following: “How are trust and distrust manifested in the relationships that users have with HCP, family, society, and themselves?” and “How are trust and distrust manifested in harm reduction as an approach to drug abuse?”A critical qualitative research study was conducted , 23. A cParticipants were PSCSU, also simply called users (of the service), their relatives, and health professionals directly involved in a specialized public mental health service, located in the North region of Brazil. Health professionals who had worked in an interdisciplinary team for a minimum of six months were invited to participate. The users selected were current clients linked to the service for at least six months, chosen by the health professionals as exemplary cases representing the complexity of needs and demands faced by the team in mental health care. Additionally, we invited one relative of each user chosen to participate in the study. We included persons who were mentioned by practitioners and users as a reference person in the care performed in the service. After obtaining ethical approval from the local university, participants were recruited. They signed an informed consent document, which described the study, risks and benefits, opportunity to withdraw, and measures to maintain confidentiality and data security.Centro de Atenção Psicossocial” (CAPSad), in Portuguese, constitutes a public health service in Brazil within the mental health care network addressing PSCSU of alcohol, crack and other drugs who are referred either from other community-based health or social services, the criminal justice system, or by self-referral. The service represents a novel landmark intervention in mental health care, providing a low-threshold environment in which the interactions between providers and users are ideally non-judgmental and the care is more accessible. The service aims to minimize harms related to problematic substance use, reducing admissions to psychiatric institutions, and promoting reintegration of these individuals into society by articulation with community service networks , my father would at least have the potential tools to start treatment.” Relative“(…) He told me that he would go to the service because they would take care of him. He knows that he will find it [care] there; it is a refuge for him.” In addition, users’ relatives pointed out that the professional team was flexible and open to talking. At the service, they trusted that users would at least have the tools necessary to begin to receive support and treatment in a caring place.HCP“The user needed help and his relationships were all severed. He had no one to assist him to find help and that's when the service came and made a difference.” HCP“The idea of this care is to strengthen, creating ways to deal with life’s problems.” HCP“We have users who have reached a level of stability in terms of their relationship with the drug; the drug is no longer an obstacle for them to live their lives.” Moreover, from the perspective of the professional team, the service represents a place of care and support for users where they could rely on the goodwill of the team. According to HCP, the service also helps users to develop strength and demonstrates how to manage everyday problems through a balanced relationship with drugs.User“I didn’t want to learn about this service. I wanted to move, go to a treatment [based on abstinence in an inpatient rehabilitation center].” User“I was there and I wanted a remedy. I was very nervous, anxious, and angry because they could not give me medication the way I wished.” In contrast, participants also pointed out aspects of the relationship in the process of care that made them distrust the harm reduction approach to treatment. For users, the idea of treatment normally entailed traditional psychiatric interventions, such as having individual appointments with a physician, taking medicines, being isolated from the community, and experiencing an inpatient regimen of abstinence at a rehab center. Therefore, users felt confused and it took time to understand the type of health care and organizational routine offered through this service.Relative“I went there [the service] with him to get his medication. I wanted him to be admitted to another service [inpatient rehabilitation center]. I was so upset.” Relative“I think the team lacks a bit of experience; many of them don’t know how to deal with users.” Similarly, relatives’ ideas of treatment mainly involved traditional psychiatric interventions and they questioned the team’s professional skills to deal with users. They too occasionally manifested distrust particularly with respect to the team’s capacity to provide the care they believed their relative needed.HCP“The user is trying, but he cannot sustain it, and just falls back.” Furthermore, professional team members expressed frustration related to users’ lapses in abstinence and relapses into intense drug use, demonstrating their lack of complete trust in the ideals of harm reduction, which are generally not abstinence-based:The care provided to drug users was still focused on specialized mental health services. In this regard, during observation, participants briefly described the need for and challenges associated with integration with primary health care services, which is key to harm reduction approaches. However, public services such as housing, security, citizenship, and social assistance, as well as community organizations that work in the area of mental health were only sometimes integrated into the work of the service, according to observation, interviews, and users’ records. Participants also did not mention in the interviews relevant clinical harm reduction actions, such as counseling and education about safer ways to use drugs; testing for HIV (human immunodeficiency virus), HVC (hepatitis C virus), HVB (hepatitis B virus), and other co-morbidities; the use of contraceptive methods and needle exchange. Moreover, observation and users’ records also showed an insufficient attention to these aspects in the care.User“(…) People who are around me need to know that I want to change.” Users recognized that abstinence and sobriety were necessary to gain trust, acceptance, and support from their relatives, the community, co-workers, and society, and frequently even from the health professional team and public health services. Indeed, according to users, trust could be gained by making noticed their desire to seek help and to change, thereby revealing the relative power that other people in the lives of PSCSU have and the fragility of trust in these relationships.User“When I am good, I sleep at my sister’s house. (…) When I go there she always has clothes to give to me; she is always taking care of me.” In addition, as a sign of trust from families, users reported having received support from relatives:References to distrust of users were much more abundant in comparison with those of trust, for all participants’ reports including those of relatives, professionals, and even users themselves.Relative“I remember my father as a drug user all my life. He spent two weeks on the street and when he wanted, came back. My mother made him soup, washed his clothes, etc. She sent everyone out  to let him sleep, for a week straight, to recover and be ready. (…) But he did not want to know [about treatment]; he went back home just to steal something, broke everything, and then left again.” HCP“(…) The addiction is so much bigger than the user.” The distrust content in participants’ reports was related to total abstinence not being a sustainable path for the majority of the users. PSCSU often had alternating cycles of abstinence and relapse during treatment, leading to the difficulties relatives and professionals have in maintaining trust in users.HCP“It is typical for users to manipulate thinking: ‘In this moment I am in need and I want to have some help.’ They use this device of needing help to get other things. Many users arrive at the service with this thought: ‘…I’m naked in the street now. I’m broke.’ Then they come to the service, in a gentle and quiet way, to get food, a place to sleep, to call family, trying to restore a connection (…). So, when the family starts to bring clothes and other personal things they need, they think: ‘now I’ve got what I wanted.’” This unstable situation leads people to see the user as someone who is untrustworthy and is always trying to take advantage of any help. They were not seen as trying to get better, but rather were labeled as “manipulative,” as the HCP pointed out:HCP“The user got to the point of his wife having to become the head of the family because everything he received as payment for work was spent on alcohol and other drugs.” Reinforcing distrust in the user and the professional’s power to define what is normal or good in the PSCSU’s life, a professional described that a user got to the point in the addiction process that he lost his capacity to continue working to provide financial support for the family.User“Most of them see you like a ‘table’ [an object]. They do not place importance on the person, because they think that person has not or will not improve in the future.” In addition, one user expressed negative feelings about the perception of distrust from HCP:User“(…) Science says that once you are a user [of drugs] you will always be.” User“I already know the suffering that I’ll have and I’ll cause people: humiliation, hunger, cold, loneliness, dirt, everything. I have done this hundreds of times and I cannot stop. I do not believe in myself. (…) My relapses are not ten or twenty; they are five hundred, a thousand. I improve physically, psychologically, and think ‘Now I’m good!’ But I wasn’t, nor I am today and I will never be.” Data regarding self-trust of the PSCSU, while scarce, was expressed by their self-perceptions of hopelessness, stigma, and other harms linked to substance misuse. Furthermore, users realized that their condition had resulted in humiliation and profound suffering for themselves and others:The nested levels of trust and distrust shown in this study revealed interconnections involving the relationships among HCP, PSCSU, and their relatives regarding a harm reduction approach, trust in users, and trust in the self of the user. Trust/distrust in each of these dimensions can influence access to health care, therapeutic responses in users, engagement of relatives in treatment, and the motivation of professionals to act and build innovations in care , 33, 34.Furthermore, the harm reduction perspective has been developed within the conflicting frameworks of public security (control of drug trafficking and use) and public health . InDrug users attended the service with a goal to get better, as well as to respond to the expectations of their family and friends. This confirmed that their motivation to seek help involved self-recognition of their poor health and life status, which included experiencing fear and exhaustion, being “disgusted” with themselves, and hitting “rock bottom,” as well as the attitudes of people who mattered to them . Users’ The outcomes and success of care were other critical points for participants. Many social opportunities for drug users in treatment are in judgmental and high-threshold settings, in which problem drug use is seen as a choice, and drug users are required to adhere to many strict rules involving complete abstinence and other freedom deprivation aspects . AlthougWhile the harm reduction perspective is criticized as having a neo-liberalism basis, with an over-emphasis on the accountability of the subject and “a prescriptive moralism, based on the duty of citizens to be healthy” , in the context of public health, it is an effective method to improve access to health care and social justice for users. Because of these benefits, the provision of a harm reduction approach has been viewed as a moral imperative for health care providers . FurtherThe ethical dimensions, particularly inequities, inherent in the network of trust are often not acknowledged, including conflicts and invisible oppression related to the international drug market, policies grounded in social control and neoliberalism, and inequities in access to health care , 46. TheThe harm reduction approach employed in this service focused on the provision of housing, access to health services, and meeting basic human needs, which may be helpful to address social determinants of health in this context, in contrast to the much-debated approach related to reducing clinical harm . AdditioSeveral limitations were present in this study. The selection of users was based on HCP’s perceptions of exemplary cases in one specialized mental health care service, which may limit the transferability of the results. In addition, although data were collected by research team members, not linked to the service, and treated confidentially, the process of data collection at the service facility may have affected participants’ responses. Nevertheless, this service represents the main public, cost-free, mental health care strategy available in Brazil, which allowed us to reflect on how PSCSU experience mental health care. Despite these limitations, each insight was grounded in theory and data triangulation, which ensured rigor.The study allowed for broad reflection on the harm reduction approach to relationships among PSCSU, their relatives, and HCP; and the challenges they experience. The critical approach used helped us to understand how an ethic of trust is related to care for providers, users, and their relatives in a public mental health care service. Participants’ perceptions of harm reduction approaches within treatment, and the ability of users to sustain themselves in treatment and to develop a better relationship with drugs demonstrated the fragility of trust in this context. The exploration of a harm reduction approach through an ethical lens can strengthen the quality of mental health policies and care provided for PSCSU.Considering the fragility of trust affecting the relationship of care discussed in our results, as concrete recommendations regarding policy and practice in the area, we suggest: investment in intersectoral engagement approaching policy and practice for people seeking care for substance use, prioritizing harm reduction strategies; the provision of society education towards stigma, marginalization and oppression involving drug use, as well as continuing education for Health Care Providers (HCP) regarding the ethical dimensions of care in this context. In addition, in the therapeutic relationship of care established between providers, users and users’ families, we recommend more dialog, clarity, and structure in expressing expectations and possibilities related to treatment, as well as better visibility and concrete measures of psychosocial improvements reached during treatment for all agents engaged in the care.