Implementing evidence-based interventions in health care: application of the replicating effective programs framework

Background

For people with dementia, patient-centred care should involve timely explanation of the diagnosis and its implications. However, this is not routine. Theoretical models of behaviour change offer a generalisable framework for understanding professional practice and identifying modifiable factors to target with an intervention. Theoretical models and empirical work indicate that behavioural intention represents a modifiable predictor of actual professional behaviour. We identified factors that predict the intentions of members of older people's mental health teams (MHTs) to perform key behaviours involved in the disclosure of dementia.

Design

Postal questionnaire survey.

Participants

Professionals from MHTs in the English National Health Service.

Methods

We selected three behaviours: Determining what patients already know or suspect about their diagnosis; using explicit terminology when talking to patients; and exploring what the diagnosis means to patients. The questionnaire was based upon the Theory of Planned Behaviour (TPB), Social Cognitive Theory (SCT), and exploratory team variables.

Main outcomes

Behavioural intentions.

Results

Out of 1,269 professionals working in 85 MHTs, 399 (31.4%) returned completed questionnaires. Overall, the TPB best explained behavioural intention. For determining what patients already know, the TPB variables of subjective norm, perceived behavioural control and attitude explained 29.4% of the variance in intention. For the use of explicit terminology, the same variables explained 53.7% of intention. For exploring what the diagnosis means to patients, subjective norm and perceived behavioural control explained 48.6% of intention.

Conclusion

These psychological models can explain up to half of the variation in intention to perform key disclosure behaviours. This provides an empirically-supported, theoretical basis for the design of interventions to improve disclosure practice by targeting relevant predictive factors.

Trial Registration

ISRCTN15871014.     

Home-based aerobic interval training improves peak oxygen uptake equal to residential cardiac rehabilitation: a randomized, controlled trial

Aerobic capacity, measured as the peak oxygen uptake, is a strong predictor of survival in cardiac patients. Aerobic interval training (AIT), walking/running four times four minutes at 85-95% of peak heart rate, has proven to be effective in increasing peak oxygen uptake in coronary heart disease patients. As some patients do not attend organized rehabilitation programs, home-based exercise should be an alternative. We investigated whether AIT could be performed effectively at home, and compared the effects on peak oxygen uptake with that observed after a standard care, four-week residential rehabilitation. Thirty patients undergoing coronary artery bypass surgery were randomized to residential rehabilitation or home-based AIT. At six months follow-up, peak oxygen uptake increased 4.6 (±2.7) and 3.9 (±3.6) mL·kg(-1) min(-1) (both p<0.005, non-significant between-group difference) after residential rehabilitation and AIT, respectively. Quality of life increased significantly in both groups, with no statistical significant difference between groups. We found no evidence for a different treatment effect between patients randomized to home-based AIT compared to patients attending organized rehabilitation (95% confidence interval -1.8, 3.5). AIT patients reported good adherence to exercise training. Even though these first data indicate positive effects of home-based AIT in patients undergoing coronary artery bypass surgery, more studies are needed to provide supporting evidence for the application of this rehabilitation strategy. Trial registration: ClinicalTrials.gov NCT00363922.     

Relationship between the behaviour of sows at 6 months old and the behaviour and performance at farrowing

Piglet crushing remains a major problem in pig production. Reduced crushing might be obtained through genetic selection on sow behavioural traits. The aim of the study was to assess the relationship between behavioural responses at 6 months of age, around farrowing, and sows' reproductive performance including crushing levels. At 6 months of age, behavioural responses of 75 nulliparous sows were observed both during behavioural tests to human presence and to the presence of a novel object in their home pen, and their responses when placed in a weighing device. At first farrowing, nervousness of the sows was observed when placed in the farrowing crate 1 week before and the day of farrowing, as well as their fear responses when approached by a human from behind or at the front of the farrowing crate. At 6 months of age, escape from a human tended to be correlated with the reactivity in the weighing device (rs = 0.21, P = 0.09). Around first farrowing, the withdrawal reaction when a human approached at the front was correlated with the fear response when approached from behind and the nervousness of the sow in the crate (rs = 0.29, P < 0.05; rs = 0.37, P < 0.01). The fear response when approached from behind was correlated with nervousness in the crate and around farrowing (rs = 0.70, P < 0.001; rs = 0.25, P < 0.05), and nervousness in the crate was significantly correlated with the nervousness around farrowing (rs = 0.34, P < 0.01). The escape from a human at 6 months was correlated with withdrawal when approached from the front before farrowing (rs = 0.38, P < 0.01) and with nervousness of the sow in the crate (rs = 0.24, P < 0.05). The number of piglets crushed at first farrowing was correlated with the latency to approach a novel object at 6 months and nervousness around farrowing (rs = -0.27, P < 0.05; rs = 0.28, P < 0.05), and tended to be correlated with the escape behaviour from human at 6 months and withdrawal away from human presence before farrowing (rs = 0.21, P = 0.09; rs = 0.22, P = 0.08). These results suggest that behavioural responses to humans and during management practices of nulliparous sows at 6 months of age are, to some extent, related with their behaviour around farrowing and crushing levels of piglets at farrowing.     

A-to-I editing of the 5HT2C receptor and behaviour.

Site-specific deamination of five adenosine residues in the pre-mRNA of the serotonin 2C receptor, 5HT2CR, alters the amino acid sequence of the encoded protein. Such RNA editing can produce 32 mRNA variants, encoding 24 protein isoforms that vary in biochemical and pharmacological properties. Because serotonin functions in the regulation of mood and behaviour, modulation of serotonin signalling by RNA editing may be relevant to such psychiatric disorders as anxiety and depression. Several recent human studies have reported changes in 5HT2CR editing in schizophrenia, major depression or suicide, but results are variable and not conclusive. Rodent studies have begun to examine effects of drug treatments and stress. Understanding the importance of 5HT2CR editing in mood and behaviour will be assisted by experiments designed to analyse multiple strains of mice, in different behavioural tests, with optimal evaluation of the time course of molecular changes.     

OPTImal CArdiac REhabilitation (OPTICARE) following Acute Coronary Syndromes: Rationale and design of a randomised, controlled trial to investigate the benefits of expanded educational and behavioural intervention programs

The majority of cardiac rehabilitation (CR) referrals consist of patients who have survived an acute coronary syndrome (ACS). Although major changes have been implemented in ACS treatment since the 1980s, which highly influenced mortality and morbidity, CR programs have barely changed and only few data are available on the optimal CR format in these patients. We postulated that standard CR programs followed by relatively brief maintenance programs and booster sessions, including behavioural techniques and focusing on incorporating lifestyle changes into daily life, can improve long-term adherence to lifestyle modifications. These strategies might result in improved (cardiac) mortality and morbidity in a cost-effective fashion. In the OPTImal CArdiac REhabilitation (OPTICARE) trial we will assess the effects of two advanced and extended CR programs that are designed to stimulate permanent adaption of a heart-healthy lifestyle, compared with current standard CR, in ACS patients. We will study the effects in terms of cardiac risk profile, levels of daily physical activity, quality of life and health care consumption.     

Sexual and maternal behaviour at the postpartum oestrus: The role of experience in time-sharing

The postpartum sexual and maternal behaviour of Norway rats (Rattus norvegicus) was observed in a seminatural habitat. Behavioural decision-making by the female was examined by disrupting the nest and newborn offspring during mating. In experiment 1, multiparous females responded to nest disruption with an increase in maternal behaviour that was largely restricted to the post-ejaculatory intervals. The temporal and frequency measures of copulation were largely unaffected, implicating behavioural time-sharing. In experiment 2, following nest disruption primiparous females did not switch efficiently between maternal and sexual behaviour, showed poor retrieval of pups, and returned to the nest during ejaculatory series. They did not display the characteristics of behavioural time-sharing, indicating that previous experience may play a role in the ability to time-share.     

A mechanistic theory of personality‐dependent movement behaviour based on dynamic energy budgets

Consistent between‐individual differences in movement are widely recognised across taxa. In addition, foraging plasticity at the within‐individual level suggests a behavioural dependency on the internal energy demand. Because behaviour co‐varies with fast‐slow life history (LH) strategies in an adaptive context, as theoretically predicted by the pace‐of‐life syndrome hypothesis, mass/energy fluxes should link behaviour and its plasticity with physiology at both between‐ and within‐individual levels. However, a mechanistic framework driving these links in a fluctuating ecological context is lacking. Focusing on home range behaviour, we propose a novel behavioural‐bioenergetics theoretical model to address such complexities at the individual level based on energy balance. We propose explicit mechanistic links between behaviour, physiology/metabolism and LH by merging two well‐founded theories, the movement ecology paradigm and the dynamic energetic budget theory. Overall, our behavioural‐bioenergetics model integrates the mechanisms explaining how (1) behavioural between‐ and within‐individual variabilities connect with internal state variable dynamics, (2) physiology and behaviour are explicitly interconnected by mass/energy fluxes, and (3) different LHs may arise from both behavioural and physiological variabilities in a given ecological context. Our novel theoretical model reveals encouraging opportunities for empiricists and theoreticians to delve into the eco‐evolutionary processes that favour or hinder the development of between‐individual differences in behaviour and the evolution of personality‐dependent movement syndromes.     

Six months of supervised high-intensity low-volume resistance training improves strength independent of changes in muscle mass in young overweight men

To determine the effects of a 6-month supervised low-volume resistance training (RT) program (1 set, 85-90%, one repetition maximum, 1RM, 3 d x wk(-1)) on muscular strength (1RM) and skeletal muscle mass (SMM) in previously sedentary, overweight men on an ad libitum diet. Nineteen men were randomly assigned to a control (CON, n = 8) or RT (n = 11) group. The exercise protocol consisted of 5 upper- and 4 lower-body exercises using weight machines. CON maintained their sedentary lifestyle. One RM for upper body (chest press [CP] + lat pull-down [LPD]) and lower body (leg press [LP]) and SMM were assessed at baseline, and at 3 and 6 months. Adherence was 96 +/- 2% with an average time to complete each exercise session of 15 +/- 2 minutes. Volume completed per exercise session significantly increased from baseline (2,812 +/- 670 kg) to 6 months (6,411 +/- 2,128 kg). There was a group by time interaction in 1RM for CP, LPD, and LP. Upper-body strength increased significantly (p < 0.001) (31.3 +/- 9.3%) from baseline to 3 months and from 3 to 6 months (17.9 +/- 8.7%). Lower-body strength also increased significantly from baseline to 3 months (17.8 +/- 16.6%) and from 3 to 6 months (32.0 +/- 33.7%). No changes in upper- or lower-body strength occurred in the CON group. There was no group by time interaction for SMM (CON, 34.5 +/- 2.9 kg vs. RT, 34.2 +/- 2.9 kg; p > 0.05) or for energy intake (p > 0.05). In conclusion, a single set resistance training program at 85% of 1RM, 3 d x wk(-1) resulted in continued increases in muscular strength and a very high adherence rate over a 6-month period in sedentary, overweight men independent of significant changes in SMM. This training protocol may increase adherence and produce long-term increases in muscular fitness as part of an adult fitness program.     

Behavioural treatment of obesity.

Behaviour modification is a promising method of therapy for obesity. Helping the patient to gain control over environmental stimuli and positive reinforcement for the acquisition of appropriate eating and exercise habits are the basis of most treatment programs. While behavioural approaches have, on the average, resulted in greater weight loss than traditional measures during active therapy, responses have been highly variable, and the eventual outcome remains to be established by long-term follow-up studies. The best results are probably achieved with a combination of behavioural therapy and other measures such as a formal exercise program. Since primary prevention may be critical to the overall control of obesity, behavioural approaches may also be applied to young children.     

Mechanism by which BMI influences leisure-time physical activity behavior

Objective: The objective of this prospective study was to clarify the mechanism by which BMI influences leisure‐time physical activity. This was achieved in accordance with the assumptions underlying the Theory of Planned Behavior (TPB), considered as one of the most useful theories to predict behavior adoption. Methods and Procedures: At baseline, a sample of 1,530 respondents completed a short questionnaire to measure intention and perceived behavioral control (PBC), the two proximal determinants of behavior of TPB. Past behavior, sociodemographic variables, and weight and height were also assessed. The dependent variable, leisure‐time physical activity was assessed 3 months later. Results: Hierarchical multiple regression analyses revealed that BMI is a direct predictor of future leisure‐time physical activity, not mediated by the variables of TPB. Additional hierarchical analyses indicated that BMI was not a moderator of the intention‐behavior and PBC‐behavior relationships. Discussion: The results of this study suggest that high BMI is a significant negative determinant of leisure‐time physical activity. This observation reinforces the importance of preventing weight gain as a health promotion strategy for avoiding a sedentary lifestyle.     

Predicting consumers’ intention to consume poultry during an H7N9 emergency: an extension of the theory of planned behavior model

Abstract

Based on the theory of planned behavior (TPB), this article explains the impact of H7N9 on poultry meat consumption. A sample of 710 respondents from China participated in the current study following an outbreak of avian influenza in 2017. The empirical results of structural equation model indicate that the consumers’ attitude, subjective norm, perceived behavioral control (i.e., the antecedents of the TPB model), as well as their anticipated fear, mediate the relationship between risk perception of H7N9 and poultry consumption intention. Risk perception of H7N9 also influences risk perception of poultry, which has a direct effect on poultry consumption intention. Furthermore, risk perception of poultry is significantly and positively related to anticipated fear and is significantly and negatively related to attitude, which in turn influences the consumption intention. The results confirm the appropriateness of the TPB model and verify that the extended TPB model has good explanatory power in predicting consumers’ intention to consume poultry during a pandemic.     

Postpartum copulatory and maternal behaviour in Norway rats under seminatural conditions

Virgin female rats were mated at a freely cycling oestrus, and then again with the same males at the subsequent postpartum oestrus. Copulatory behaviour at each mating was compared and the temporal patterning of the female's mating and maternal behaviour was analysed. Postpartum females were found to conserve the number of ejaculatory series received, yet the series were shorter, resulting in a shorter time being occupied, by this mating. During mating, females spent little time with their litters, and then mainly in the post-ejaculatory intervals. Ejaculatory series were rarely disrupted by nesting. The postpartum female rat seems to engage in behavioural time-sharing.     

Factors affecting intention to receive and self-reported receipt of 2009 pandemic (H1N1) vaccine in Hong Kong: a longitudinal study

Background

Vaccination was a core component for mitigating the 2009 influenza pandemic (pH1N1). However, a vaccination program''s efficacy largely depends on population compliance. We examined general population decision-making for pH1N1 vaccination using a modified Theory of Planned Behaviour (TBP).

Methodology

We conducted a longitudinal study, collecting data before and after the introduction of pH1N1 vaccine in Hong Kong. Structural equation modeling (SEM) tested if a modified TPB had explanatory utility for vaccine uptake among adults.

Principal Findings

Among 896 subjects who completed both the baseline and the follow-up surveys, 7% (67/896) reported being “likely/very likely/certain” to be vaccinated (intent) but two months later only 0.8% (7/896) reported having received pH1N1 vaccination. Perception of low risk from pH1N1 (60%) and concerns regarding adverse effects of the vaccine (37%) were primary justifications for avoiding pH1N1 vaccination. Greater perceived vaccine benefits (β = 0.15), less concerns regarding vaccine side-effects (β = −0.20), greater adherence to social norms of vaccination (β = 0.39), anticipated higher regret if not vaccinated (β = 0.47), perceived higher self-efficacy for vaccination (β = 0.12) and history of seasonal influenza vaccination (β = 0.12) were associated with higher intention to receive the pH1N1 vaccine, which in turn predicted self-reported vaccination uptake (β = 0.30). Social norm (β = 0.70), anticipated regret (β = 0.19) and vaccination intention (β = 0.31) were positively associated with, and accounted for 70% of variance in vaccination planning, which, in turn subsequently predicted self-reported vaccination uptake (β = 0.36) accounting for 36% of variance in reported vaccination behaviour.

Conclusions/Significance

Perceived low risk from pH1N1 and perceived high risk from pH1N1 vaccine inhibited pH1N1 vaccine uptake. Both the TPB and the additional components contributed to intended vaccination uptake but social norms and anticipated regret predominantly associated with vaccination intention and planning. Vaccination planning is a more significant proximal determinant of uptake of pH1N1 vaccine than is intention. Intention alone is an unreliable predictor of future vaccine uptake.     

Mutual ornamentation and the parental behaviour of male and female Collared Flycatchers Ficedula albicollis during incubation

One of the benefits of mate choice based on sexually selected traits is the greater investment of more ornamented individuals in parental care. The choosy individual can also adjust its parental investment to the sexual signals of its partner. Incubation is an important stage of avian reproduction, but the relationship between behaviour during incubation and mutual ornamentation is unclear. Studying a population of Collared Flycatchers Ficedula albicollis, we monitored the behaviour of both sexes during incubation in relation to their own and their partner's plumage traits, including plumage‐level reflectance attributes and white patch sizes. There was a marginally positive relationship between male feeding rate during incubation and female incubation rate. Female but not male behavioural traits were associated with the laying date of the first egg and clutch size. The behaviour of the two sexes jointly determined the relative hatching speed of clutches and the hatching success of eggs. Females with larger white wing patches spent less time incubating eggs and left the nestbox more frequently. Males with larger white wing patches fed females less frequently, whereas males with brighter white plumage areas visited the nestbox more regularly without feeding. Females tended to leave the nest less often when mated to males with larger wing patches, and females spent less time incubating when males had more UV chromatic plumage. The behaviour of both partners during incubation therefore predicted hatching patterns and was correlated with their own and sometimes with their partner's plumage ornamentation. These results call for further studies of mutual ornamentation and reproductive effort during incubation.     

Effects of a 12-wk resistance exercise program on skeletal muscle strength in children with burn injuries.

The posttraumatic response to burn injury leads to marked and prolonged skeletal muscle catabolism and weakness, which persist despite standard rehabilitation programs of occupational and physical therapy. We investigated whether a resistance exercise program would attenuate muscle loss and weakness that is typically found in children with thermal injury. We assessed the changes in leg muscle strength and lean body mass in severely burned children with >40% total body surface area burned. Patients were randomized to a 12-wk standard hospital rehabilitation program supplemented with an exercise training program (n = 19) or to a home-based rehabilitation program without exercise (n = 16). Leg muscle strength was assessed before and after the 12-wk rehabilitation or training program at an isokinetic speed of 150 degrees /s. Lean body mass was assessed using dual-energy X-ray absorptiometry. We found that the participation in a resistance exercise program results in a significant improvement in muscle strength, power, and lean body mass relative to a standard rehabilitation program without exercise.     

Individual differences in behaviour explain variation in survival: a meta‐analysis

Research focusing on among‐individual differences in behaviour (‘animal personality’) has been blooming for over a decade. Central theories explaining the maintenance of such behavioural variation posits that individuals expressing greater “risky” behaviours should suffer higher mortality. Here, for the first time, we synthesize the existing empirical evidence for this key prediction. Our results did not support this prediction as there was no directional relationship between riskier behaviour and greater mortality; however there was a significant absolute relationship between behaviour and survival. In total, behaviour explained a significant, but small, portion (5.8%) of the variance in survival. We also found that risky (vs. “shy”) behavioural types live significantly longer in the wild, but not in the laboratory. This suggests that individuals expressing risky behaviours might be of overall higher quality but the lack of predation pressure and resource restrictions mask this effect in laboratory environments. Our work demonstrates that individual differences in behaviour explain important differences in survival but not in the direction predicted by theory. Importantly, this suggests that models predicting behaviour to be a mediator of reproduction‐survival trade‐offs may need revision and/or empiricists may need to reconsider their proxies of risky behaviours when testing such theory.     

Study protocol: EXERcise and Cognition in Sedentary adults with Early-ONset dementia (EXERCISE-ON)

ABSTRACT: BACKGROUND: Although the development of early-onset dementia is a radical and invalidating experience for both patient and family there are hardly any non-pharmacological studies that focus on this group of patients. One type of a non-pharmacological intervention that appears to have a beneficial effect on cognition in older persons without dementia and older persons at risk for dementia is exercise. In view of their younger age early-onset dementia patients may be well able to participate in an exercise program. The main aim of the EXERCISE-ON study is to assess whether exercise slows down the progressive course of the symptoms of dementia. METHODS: One hundred and fifty patients with early-onset dementia are recruited. After completion of the baseline measurements, participants living within a 50 kilometre radius to one of the rehabilitation centres are randomly assigned to either an aerobic exercise program in a rehabilitation centre or a flexibility and relaxation program in a rehabilitation centre. Both programs are applied three times a week during 3 months. Participants living outside the 50 kilometre radius are included in a feasibility study where participants join in a daily physical activity program set at home making use of pedometers. Measurements take place at baseline (entry of the study), after three months (end of the exercise program) and after six months (follow-up). Primary outcomes are cognitive functioning; psychomotor speed and executive functioning; (instrumental) activities of daily living, and quality of life. Secondary outcomes include physical, neuropsychological, and rest-activity rhythm measures. DISCUSSION: The EXERCISE-ON study is the first study to offer exercise programs to patients with early-onset dementia. We expect this study to supply evidence regarding the effects of exercise on the symptoms of early-onset dementia, influencing quality of life.Trial registrationThe present study is registered within The Netherlands National Trial Register (ref: NTR2124).     

Pedal Claw Curvature in Birds,Lizards and Mesozoic Dinosaurs – Complicated Categories and Compensating for Mass-Specific and Phylogenetic Control

Pedal claw geometry can be used to predict behaviour in extant tetrapods and has frequently been used as an indicator of lifestyle and ecology in Mesozoic birds and other fossil reptiles, sometimes without acknowledgement of the caveat that data from other aspects of morphology and proportions also need to be considered. Variation in styles of measurement (both inner and outer claw curvature angles) has made it difficult to compare results across studies, as have over-simplified ecological categories. We sought to increase sample size in a new analysis devised to test claw geometry against ecological niche. We found that taxa from different behavioural categories overlapped extensively in claw geometry. Whilst most taxa plotted as predicted, some fossil taxa were recovered in unexpected positions. Inner and outer claw curvatures were statistically correlated, and both correlated with relative claw robusticity (mid-point claw height). We corrected for mass and phylogeny, as both likely influence claw morphology. We conclude that there is no strong mass-specific effect on claw curvature; furthermore, correlations between claw geometry and behaviour are consistent across disparate clades. By using independent contrasts to correct for phylogeny, we found little significant relationship between claw geometry and behaviour. ‘Ground-dweller’ claws are less curved and relatively dorsoventrally deep relative to those of other behavioural categories; beyond this it is difficult to assign an explicit category to a claw based purely on geometry.     

Diet composition,adherence to calorie restriction,and cardiometabolic disease risk modification

Calorie restriction (CR) is a promising approach for attenuating the risk of age-related disease. However, the role of diet composition on adherence to CR and the effects of CR on cardiometabolic markers of healthspan remains unknown. We used the Geometric Framework for Nutrition approach to examine the association between macronutrient composition and CR adherence during the 2-year CALERIE trial. Adult participants without obesity were randomized to a 25% CR intervention or an ad libitum intake control. Correlations of cardiometabolic risk factors with macronutrient composition and standard dietary pattern indices [Alternate Mediterranean Diet Index (aMED), Dietary Inflammatory Index (DII), and Healthy Eating Index (HEI)] were also evaluated by Spearman's correlation at each time point. The mean age was 38.1 ± 7.2 years at baseline and the mean BMI was 25.1 ± 1.7. The study population was 70% female. The CR group, but not the control, consumed a higher percentage reported energy intake from protein and carbohydrate and lower fat at 12 months compared to baseline; comparable results were observed at 24 months. Protein in the background of higher carbohydrate intake was associated with greater adherence at 24 months. There was no correlation between macronutrient composition and cardiometabolic risk factors in the CR group. However, statistically significant correlations were observed for the DII and HEI. These findings suggest that individual self-selected macronutrients have an interactive but not independent role in CR adherence. Additional research is required to examine the impact of varying macronutrient compositions on adherence to CR and resultant modification to cardiometabolic risk factors.     

Prediction of reduction in aggressive behaviour of growing pigs using skin lesion traits as selection criteria

Aggression at regrouping is a common issue in pig farming. Skin lesions are genetically and phenotypically correlated with aggression and have been shown to have a significant heritable component. This study predicts the magnitude of reduction in complex aggressive behavioural traits when using lesion numbers on different body regions at two different time points as selection criteria, to identify the optimum skin lesion trait for selection purposes. In total, 1146 pigs were mixed into new social groups, and skin lesions were counted 24 h (SL24h) and 3 weeks (SL3wk) post-mixing, on the anterior, centre and posterior regions of the body. An animal model was used to estimate genetic parameters for skin lesion traits and 14 aggressive behavioural traits. Estimated breeding values (EBVs) and phenotypic values were scaled and standardised to allow direct comparison across multiple traits. Individuals with SL24h and SL3wk EBVs in the least aggressive 10% of the population were compared with the population mean to predict the expected genetic and phenotypic response in aggressive behaviour to selection. At mixing, selection for low anterior lesions was predicted to affect substantially more behavioural traits of aggressiveness than lesions obtained on other body parts, with EBVs between −0.21 and −1.17 SD below the population mean. Individuals with low central SL24h EBVs also had low EBVs for aggressive traits (−0.33 to −0.55). Individuals with high SL3wk EBVs had low EBVs for aggression at mixing (between −0.24 and −0.53 SD below the population mean), although this was predicted to affect fewer traits than selection against SL24h. These results suggest that selection against anterior SL24h would result in the greatest genetic and phenotypic reduction in aggressive behaviour recorded at mixing. Selection for increased SL3wk was predicted to reduce aggression at mixing; however, current understanding about aggressive behaviour under stable social conditions is insufficient to recommend using this trait for selection purposes.