Restoration in mental health after visiting urban green spaces, who is most affected? Comparison between good/poor mental health in four European cities.

Several mechanisms have been proposed to explain the association between green space and health, and one of these is the restoration theory, based on the idea that it is possible to increase mental health and decrease stress visiting a natural environment. The aims of the present study were to understand what activities are most related to restoration and if these are the same for people with poorer and better mental health. A questionnaire was administered in four European cities and data about restoration outcomes, type of activity carried out in green spaces and mental health were collected and analyzed. A cross sectional design was used and total of 3134 respondents participated to the questionnaire. The restoration experience was measured with the restoration outcome score, and the mental health was evaluated with a subscale related to mental health of the Medical Outcome Short Form. Participants were divided in two groups according to mental health score. A multiple regression analysis was performed to investigate the association between mental health, type of activity and restoration. The cities showed a similar trend in the association between restoration and type of activity performed in green environment. People with poorer mental health seem to be more sensitive to the positive effect of visiting the green environment and restoration was more evident in these people than in those with better mental health. At the same time, the type of activity was less evident in people with better mental health, and they seemed to be less influenced by the visiting of green space. Green prescription is important for the entire population: people with poorer mental health could have important restorative effects and people with better mental health could continue to protect their well-being using green space.

A free-produce stand on campus: impact on fruit and vegetable intake in Dutch university students.

OBJECTIVE: To investigate the effects of providing free fruit and snack vegetables at a university on students' fruit intake, snack vegetable intake and total vegetable intake. DESIGN: Free fruit and raw snack vegetables (e.g. bite-sized tomatoes) were provided in a stand in the form of a miniature wooden house located in the central hall of the university's main building, which students regularly pass through on their way to lectures and the cafeteria. Three interventions tested with a pre-test/post-test design were performed. In these three interventions, small changes to the appearance of the stand were made, such as placing potted plants around it. Demographic characteristics and fruit and vegetable intakes were assessed with questionnaires. SETTING: A Dutch university of applied science. PARTICIPANTS: Intervention 1 included 124 students; Intervention 2 included ninety-two students; Intervention 3 included 237 students. RESULTS: Longitudinal linear regression analyses showed that post-test snack vegetable intake was consistently higher compared with pre-test. In the three interventions, post-test snack vegetable intakes were between 11 and 14 g/d higher than at the pre-test, which is comparable to three bite-sized tomatoes. No differences in fruit intake or total vegetable intake were found. Subgroup analyses showed that, in all three interventions, students with the lowest pre-test fruit intake and total vegetable intake reported the largest increase in fruit intake and snack vegetable intake after the interventions. CONCLUSIONS: Providing free fruit and vegetables to students at their university might be beneficial for those with low habitual intakes.

Fruit and vegetable intakes, associated characteristics and perceptions of current and future availability in Dutch university students.

OBJECTIVE: To investigate fruit and vegetable (F&V) intakes of university students and associated demographic and lifestyle characteristics, and students' perceptions of F&V availability and F&V intervention strategies in the university environment. DESIGN: Cross-sectional questionnaire data were collected; F&V intakes were measured using a food frequency tool. Multivariable linear regression analyses were used to analyse the associations between demographic and lifestyle characteristics and F&V intakes. SETTING: Universities in the Netherlands. SUBJECTS: University students (n 717). RESULTS: The majority of students did not adhere to Dutch F&V guidelines (71 % and 93 %, respectively). Fruit intake was lower among students who were male, living independently, enrolled in a technical study, not adhering to physical activity guidelines, and heavy to excessive alcohol drinkers. Vegetable intake was lower among students who were non-Dutch, living with their parents, not adhering to physical activity guidelines, and moderate and heavy to excessive alcohol drinkers. Most students perceived that their university environment offers sufficient healthy foods (60 %) and F&V (65 %), but also indicated that their F&V intakes would increase with interventions concerning affordable F&V in the university canteen (64 %) or university supermarket (60 %). Students were less disposed to indicate that weekly local farmers' markets, vegetable parcels or a vegetable garden would increase their F&V intakes. CONCLUSIONS: Dutch university students do not consume enough F&V. Future efforts that aim to promote students' F&V intakes should consider the differences between subgroups based on demographic and lifestyle characteristics and that affordable F&V in the university environment might be an effective strategy.

Do Physical Activity, Social Cohesion, and Loneliness Mediate the Association Between Time Spent Visiting Green Space and Mental Health?

This cross-sectional study investigated whether physical activity, social cohesion, and loneliness mediate the association between time spent visiting green spaces and perceived mental health and vitality. Questionnaire data were collected from 3,948 residents from 124 neighborhoods across four European cities. Multilevel linear regression analysis revealed positive, but weak, associations between time spent visiting green space and Medical Outcome Study Short Form (SF-36) mental health and vitality score, which suggest small mental health benefits. Single mediation analyses showed that different indicators of physical activity (total, during leisure time, and walking during leisure time), social cohesion, and loneliness were mediators. Multiple mediation analyses showed that physical activity during leisure time and loneliness may explain about 25% of the relationship. The unmediated part of the association suggests that other mediators may explain the association.

The relationship between natural outdoor environments and cognitive functioning and its mediators.

BACKGROUND: Urban residents may experience cognitive fatigue and little opportunity for mental restoration due to a lack of access to nature. Natural outdoor environments (NOE) are thought to be beneficial for cognitive functioning, but underlying mechanisms are not clear. OBJECTIVES: To investigate the long-term association between NOE and cognitive function, and its potential mediators. METHODS: This cross-sectional study was based on adult participants of the Positive Health Effects of the Natural Outdoor Environment in Typical Populations in Different Regions in Europe (PHENOTYPE) project. Data were collected in Barcelona, Spain; Doetinchem, the Netherlands; and Stoke-on-Trent, United Kingdom. We assessed residential distance to NOE, residential surrounding greenness, perceived amount of neighborhood NOE, and engagement with NOE. Cognitive function was assessed with the Color Trails Test (CTT). Mediation analysis was undertaken following Baron and Kenny. RESULTS: Each 100m increase in residential distance to NOE was associated with a longer CTT completion time of 1.50% (95% CI 0.13, 2.89). No associations were found for other NOE indicators and cognitive function. Neighborhood social cohesion was (marginally) significantly associated with both residential distance to NOE and CTT completion time, but no evidence for mediation was found. Nor were there indications for mediation by physical activity, social interaction with neighbors, loneliness, mental health, air pollution worries, or noise annoyance. CONCLUSIONS: Our findings provide some indication that proximity to nature may benefit cognitive function. We could not establish which mechanisms may explain this relationship.

Natural outdoor environments and mental health: Stress as a possible mechanism.

INTRODUCTION: Better mental health has been associated with exposure to natural outdoor environments (NOE). However, comprehensive studies including several indicators of exposure and outcomes, potential effect modifiers and mediators are scarce. OBJECTIVES: We used novel, objective measures to explore the relationships between exposure to NOE (i.e. residential availability and contact) and different indicators of mental health, and possible modifiers and mediators. METHODS: A nested cross-sectional study was conducted in: Barcelona, Spain; Stoke-on-Trent, United Kingdom; Doetinchem, Netherlands; Kaunas, Lithuania. Participants' exposure to NOE (including both surrounding greenness and green and/or blue spaces) was measured in terms of (a) amount in their residential environment (using Geographical Information Systems) and (b) their contact with NOE (using smartphone data collected over seven days). Self-reported information was collected for mental health (psychological wellbeing, sleep quality, vitality, and somatisation), and potential effect modifiers (gender, age, education level, and city) and mediators (perceived stress and social contacts), with additional objective NOE physical activity (potential mediator) derived from smartphone accelerometers. RESULTS: Analysis of data from 406 participants showed no statistically significant associations linking mental health and residential NOE exposure. However, NOE contact, especially surrounding greenness, was statistically significantly tied to better mental health. There were indications that these relationships were stronger for males, younger people, low-medium educated, and Doetinchem residents. Perceived stress was a mediator of most associations, and physical activity and social contacts were not. CONCLUSIONS: Our findings indicate that contact with NOE benefits mental health. Our results also suggest that having contact with NOE that can facilitate stress reduction could be particularly beneficial.

Neighbourhood safety and leisure-time physical activity among Dutch adults: a multilevel perspective.

BACKGROUND: Several neighbourhood elements have been found to be related to leisure-time walking and cycling. However, the association with neighbourhood safety remains unclear. This study aimed to assess the association of neighbourhood-level safety with leisure-time walking and cycling among Dutch adults. METHODS: Data were derived from the national health survey (POLS) 2006-2009, with valid data on 20046 respondents residing in 2127 neighbourhoods. Multilevel logistic regression models were used to examine the association between neighbourhood-level safety (general safety and specific safety components: physical disorder, social disorder, crime-related fear, traffic safety) and residents' engagement in outdoor leisure-time walking and cycling for at least 30 minutes per week. RESULTS: An increase in neighbourhood safety (both general safety and each of the safety components) was significantly associated with an increase in leisure-time cycling participation. Associations were strongest for general safety and among older women. In the general population, neighbourhood safety was not significantly associated with leisure-time walking. However, among younger and older adult men and lower educated individuals, an increase in general safety was associated with a decrease in leisure-time walking participation. CONCLUSIONS: In the Netherlands, neighbourhood safety appears to be related to leisure-time cycling but not to walking. Leisure-time cycling may best be encouraged by improving different safety components at once, rather than focusing on one safety aspect such as traffic safety. Special attention is needed for older women.

Schoolyard physical activity of 6-11 year old children assessed by GPS and accelerometry.

BACKGROUND: Children's current physical activity levels are disturbingly low when compared to recommended levels. This may be changed by intervening in the school environment. However, at present, it is unclear to what extent schoolyard physical activity contributes towards reaching the daily physical activity guideline. The aim of this study was to examine how long and at what intensity children are physically active at the schoolyard during different time segments of the day. Moreover, the contribution of schoolyard physical activity towards achieving the recommended guideline for daily physical activity was investigated. METHODS: Children (n=76) between the age of 6-11 years were recruited in six different schools in five cities (>70.000 residents) in the Netherlands. During the weekdays of a regular school week, childrens' physical activity and location were measured with ActiGraph accelerometers and Travelrecorder GPS receivers. Data was collected from December 2008 to April 2009. From the data, the amount of moderate to vigorous physical activity (MVPA) on and outside the schoolyard was established. Moreover, the percentage of MVPA on the schoolyard was compared between the following segments of the day: pre-school, school, school recess, lunch break and post-school. Differences between boys and girls were compared using linear and logistic mixed-effects models. RESULTS: On average, children spent 40.1 minutes/day on the schoolyard. During this time, boys were more active on the schoolyard, with 27.3% of their time spent as MVPA compared to 16.7% among girls (OR=2.11 [95% CI 1.54 - 2.90]). The children were most active on the schoolyard during school recess, during which boys recorded 39.5% and girls recorded 23.4% of the time as MVPA (OR=2.55 [95% CI: 1.69 - 3.85]). Although children were only present at the schoolyard for 6.1% of the total reported time, this time contributed towards 17.5% and 16.8% of boys' and girls' minutes of MVPA. CONCLUSIONS: On the schoolyard, children's physical activity levels are higher than on average over the whole day. Physical activity levels are particularly high during school recess. The school environment seems to be an important setting for improving children's physical activity levels. Further research on the facilitators of these high activity levels may provide targets for further promotion of physical activity among children.

Social Workers' Choice Making in Supporting Nature Activities by Parents and Children in Shelters.

Visiting a natural environment such as a garden or park helps people to recover from stressful circumstances. Women's shelters and homeless shelters have started to integrate nature in their work, especially for families who seek temporary refuge, with the aim to support parents' functioning and resilience. For professionals who want to facilitate engagement with nature among their clients, it may be helpful to learn how other professionals choose nature activities for the support of parents. The current study was aimed to uncover how social workers choose a nature activity for the support of parents, resulting in a model that can be used as a reflective tool among shelter professionals. The model is based on an analysis of actions of professionals, captured in case descriptions written by shelter professionals about parenting supportive nature activities that they facilitated for families under their care. The model shows that social workers promoted a back-and-forth between children's exploration away from the parent and being with the parent. In facilitating these interactions, social workers used nature as an environment with stress reducing and strengthening capacities for parents and as an environment with supportive qualities for children's play. A dimensional framework was extracted that described how professionals may choose activities.

Use of the Natural Outdoor Environment in Different Populations in Europe in Relation to Access: Implications for Policy.

This cross-cultural study explores the relationship of natural outdoor environment (NOE) use with NOE access. Most urban planning recommendations suggest optimal accessibility to be 300 m-500 m straight distance to spaces with vegetation of at least 1 hectare. Exploring this recommendation, we used data (n = 3947) from four European cities collected in the framework of the PHENOTYPE study: Barcelona (Spain), Doetinchem (The Netherlands), Kaunas (Lithuania) and Stoke-on-Trent (United Kingdom) to obtain residential access to NOE (straight or network distances, using 300 m and 150 m buffers, to NOE larger than 1 hectare or 0.5 hectare) and use of NOE (i.e., self-reported time spent in NOE). Poisson regression models were used to examine the associations between residential access and use of NOE. The models with the strongest association with time spent in NOE in the combined sample were for those living within 300 m straight line distance to either 0.5 ha or 1 ha NOE. Noting that the only indicator that was consistent across all individual cities was living with 150 m network buffer of NOE (of at least 1 ha), this warrants further exploration in reducing recommendations of 300 m straight-line distance to 150 m network distance to 1 ha of NOE for a general indicator for cities within Europe.

Viewing Nature Lets Your Mind Run Free: Three Experiments about the Influence of Viewing a Nature Video on Cognitive Coping with Psychological Distress.

Viewing nature has restorative qualities that might help people cope with their personal struggles. Three lab experiments (N = 506) studied whether environment (nature vs. built) influences cognitive coping with psychological distress. Psychological distress was induced with an autobiographical recall task about serious regret, whereafter participants were randomly assigned to view a nature or built video. Cognitive coping (i) Quantity, (ii) Content, and (iii) Quality were hereafter assessed as well as extent and vividness of the regretful memory during the video. Results showed a higher cognitive coping Quantity (Study 1 and 3) and a higher cognitive coping Quality (All studies) for the nature (vs. built) condition. Regarding cognitive coping Content, results varied across the studies. Additionally, participants reported to have thought about the experienced psychological distress to a greater extent while viewing the nature (vs. built) video. Yet they did rate viewing nature as more relaxing. We propose a two-step pathway as an underlying mechanism of restoration. In the first step the capacity for directed attention replenishes. Secondly, this renewed capacity is directed towards internal processes, creating the optimal setting for reflection. Hence, viewing nature allows people to truly process whatever is occupying their minds, which is ultimately relieving and beneficial for mental health.

The Value of Nature During Psychotherapy: A Qualitative Study of Client Experiences.

Nature is considered to have restorative qualities that can potentially improve psychotherapy success. However, little is known about how clients experience nature during psychotherapy. The research aim of this phenomenological qualitative study was to study how clients experience nature during individual outpatient psychotherapy that took place while walking in nature. More specifically we were interested in clients' inner world experiences. All participants (N = 12) received treatment through licensed therapists for a DSM-5 classified disorder. Semi-structured interviews were conducted. To uncover true lived experiences during these interviews, participants were asked to close their eyes and envision themselves during a psychotherapy session in nature. The verbatim transcripts were coded by means of inductive thematic analysis and the results were member checked. Results showed that nature brings clients closer to their inner worlds. How nature brings this about is unfolded in a conceptual model of lived experience. We argue that psychotherapy can be enriched by considering nature as a supportive environment because bringing clients closer to their inner worlds is of essential value in facilitating successful treatment interventions.

Experiencing Nature to Satisfy Basic Psychological Needs in Parenting: A Quasi-Experiment in Family Shelters.

Finding fulfillment of basic psychological needs may be difficult for parents living in shelters after becoming homeless or after escaping violence. This study tested if experiencing nature was associated with the basic psychological needs of parents in shelters. Need satisfaction and need frustration were measured among parents in shelters (N = 160), with one measurement in the standard indoor context of the shelter and one measurement while experiencing nature. Experiencing nature was associated with enhanced need satisfaction (d = 0.28) and reduced need frustration (d = -0.24). The effect was especially pronounced for parents with young children. Our findings suggest that the physical environment matters for parents' basic psychological need fulfillment as they interact with their children in the context of sheltering. This finding opens a potential avenue for supporting parental functioning and resilience in the face of risk if these effects were to be replicated across settings using controlled experimental designs. At the very least, the findings may be discussed with practitioners and parents in the context of making shelter life and work more conducive to mental health and family functioning.

Nature in the indoor and outdoor study environment and secondary and tertiary education students' well-being, academic outcomes, and possible mediating pathways: A systematic review with recommendations for science and practice.

This study reviews the evidence on the effects of nature in the study environment on well-being, academic outcomes, and outcomes related to possible explanatory pathways among students in secondary and tertiary education. The protocol was preregistered at Prospero (CRD42019126718). A systematic search of two databases yielded 3410 articles, of which 37 studies were included in the review. Most studies had a high risk of bias and there were heterogeneous outcome and exposure measures. Hence, no firm conclusions could be drawn. However, potentially promising leads were found on the associations between campus green space and improved quality of life, perceived restoration, lower outdoor temperature, and between indoor nature and improved indoor climate.

Momentary mood response to natural outdoor environments in four European cities.

Exposure to natural outdoor environments (NOE) has been shown in population-level studies to reduce anxiety and psychological distress. This study investigated how exposure to one's everyday natural outdoor environments over one week influenced mood among residents of four European cities including Barcelona (Spain), Stoke-on-Trent (United Kingdom), Doetinchem (The Netherlands) and Kaunas (Lithuania). Participants (n = 368) wore a smartphone equipped with software applications to track location and mood (using mobile ecological momentary assessment (EMA) software), for seven consecutive days. We estimated random-effects ordered logistic regression models to examine the association between mood (positive and negative affect), and exposure to green space, represented by two binary variables indicating exposure versus no exposure to NOE using GPS tracking and satellite and aerial imagery, 10 and 30 min prior to participants' completing the EMA. Models were adjusted for home city, day of the week, hour of the day, EMA survey type, residential NOE exposure, and sex, age, education level, mental health status and neighbourhood socioeconomic status. In addition, we tested for heterogeneity of effect by city, sex, age, residential NOE exposure and mental health status. Within 10 min of NOE exposure, compared to non-exposure, we found that overall there was a positive relationship with positive affect (OR: 1.39, 95% CI: 1.06, 1.81) of EMA surveys, and non-significant negative association with negative affect (OR: 0.80, 95% CI: 0.58, 1.10). When stratifying, associations were consistently found for Stoke-on-Trent inhabitants and men, while findings by age group were inconsistent. Weaker and less consistent associations were found for exposure 30 min prior to EMA. Our findings support increasing evidence of psychological and mental health benefits of exposure to natural outdoor environments, especially among urban populations such as those included in our study.

Exploring mechanisms underlying the relationship between the natural outdoor environment and health and well-being - Results from the PHENOTYPE project.

BACKGROUND: Despite the large number of studies on beneficial effects of the natural outdoor environment (NOE) on health, the underlying mechanisms are not fully understood. OBJECTIVE: This study explored the relations between amount, quality, use and experience of the NOE; and physical activity, social contacts and mental well-being. METHODS: In this cross-sectional study, data on GIS-derived measures of residential surrounding greenness (NDVI), NOE within 300 m, and audit data on quality of the streetscape were combined with questionnaire data from 3947 adults in four European cities. These included time spent in NOE (use); and perceived greenness, and satisfaction with and importance given to the NOE (experience). Physical activity, social contacts and mental health were selected as key outcome indicators. Descriptive and multilevel analyses were conducted both on pooled data and for individual cities. RESULTS: More minutes spent in the NOE were associated with more minutes of physical activity, a higher frequency of social contacts with neighbors, and better mental well-being. Perceived greenness, satisfaction with and importance of the NOE, were other strong predictors of the outcomes, while GIS measures of NOE and streetscape quality were not. We found clear differences between the four cities. CONCLUSIONS: Use and experience of the natural outdoor environment are important predictors for beneficial effects of the natural outdoor environment and health. Future research should focus more on these aspects to further increase our understanding of these mechanisms, and needs to take the local context into account.

Social contacts as a possible mechanism behind the relation between green space and health.

This study explored whether social contacts are an underlying mechanism behind the relationship between green space and health. We measured social contacts and health in 10,089 residents of the Netherlands and calculated the percentage of green within 1 and a 3km radius around the postal code coordinates for each individual's address. After adjustment for socio-economic and demographic characteristics, less green space in people's living environment coincided with feelings of loneliness and with perceived shortage of social support. Loneliness and perceived shortage of social support partly mediated the relation between green space and health.

Green Schoolyards as Outdoor Learning Environments: Barriers and Solutions as Experienced by Primary School Teachers.

With a growing number of primary schools around the globe greening their schoolyards, opportunities arise to realize outdoor learning in natural areas on the school's premises. Despite their promising potential, green schoolyards as outdoor learning environments remain mostly unintegrated in teachers' educational practices. In the current study, teachers of five primary schools in Netherlands were followed for two consecutive years during a participatory action research project. Based on their experiences in this project, teachers identified barriers when integrating the green schoolyard as a learning environment and found practice-based solutions to overcome these barriers. Across schools, a total of 20 meetings were organized, with 75 teachers participating in the project. Results revealed four broad themes encompassing barriers and solutions. Teachers feel hindered by outdoor learning having no formal status in their current educational practice, experience barriers related to a lack of confidence in their own outdoor teaching expertise, find it difficult to get started, and experience barriers related to physical constraints. Teachers, professionals, and researchers together found solutions to overcome each specific barrier. These solutions can be translated to general recommendations: just do it, get educated and inspired, engage in real-life experiences, get an outdoor pedagogical mindset, and follow a tailored process. The findings can be used by primary schools and other institutions to develop interventions that support teachers to further integrate the green schoolyard as a learning environment.

Dog ownership, the natural outdoor environment and health: a cross-sectional study.

OBJECTIVES: Dog owners walking their dog in natural outdoor environments (NOE) may benefit from the physical activity facilitated by dog walking and from time spent in nature. However, it is unclear whether dog owners receive additional health benefits associated with having access to NOE above the physical activity benefit of walking with their dog. We investigated associations between dog ownership, walking, time spent in NOE and health and whether these associations differed among those with good and poor access to NOE and those living in green and less green areas. DESIGN: Cross-sectional study. SETTING: The Positive Health Effects of the Natural Outdoor Environment in Typical Populations in Different Regions in Europe project. PARTICIPANTS: n=3586 adults from Barcelona (Spain), Doetinchem (the Netherlands), Kaunas (Lithuania) and Stoke-on-Trent (UK). DATA COLLECTION AND ANALYSIS: We calculated access to NOE with land maps and residential surrounding greenness with satellite data. Leisure time walking, time spent in NOE and general and mental health status were measured using validated questionnaires. Associations were estimated using multilevel analysis with a random intercept defined at the neighbourhood level. RESULTS: Dog ownership was associated with higher rates of leisure time walking and time spending in NOE (OR 2.17, 95% CI 1.86 to 2.54 and 2.37, 95% CI 2.02 to 2.79, respectively). These associations were stronger in those living within 300 m of a NOE and in greener areas. No consistent associations were found between dog ownership and perceived general or mental health status. CONCLUSIONS: Compared with non-dog owners, dog owners walked more and spent more time in NOE, especially those living within 300 m of a NOE and in greener areas. The health implications of these relationships should be further investigated. In a largely physically inactive society, dog walking in NOE may be a simple way of promoting physical activity and health.

Circulating mitochondrial nucleic acids have prognostic value for survival in patients with advanced prostate cancer.

PURPOSE: Advanced prostate cancer represents a heterogeneous disease entity with differences in clinical behavior, response to therapy, and survival. We assessed whether we could distinguish poor from good prognosis patients at presentation in our clinic by means of quantifying circulating cell-free mitochondrial and genomic nucleic acids in plasma. EXPERIMENTAL DESIGN: We collected plasma from 75 prostate cancer patients and from 14 subjects with benign disease. Nucleic acids were isolated, and mitochondrial DNA (mtDNA; 16S rRNA), mitochondrial RNA (mtRNA; cytochrome c oxidase subunit 1), and genomic DNA (U1A DNA) transcripts were quantified by real-time amplification. An association between cell-free nucleic acids and metastasis, prostate-specific antigen doubling time, and hemoglobin levels was determined. Multivariate Cox proportional hazard and survival estimation studies were done. RESULTS: We show that elevated mtDNA and mtRNA levels are present in plasma of prostate cancer patients with a poor 2-year survival (P = 0.02 and 0.003, respectively). Cancer patients with high plasma mitochondrial nucleic acids, using a calculated optimal cutoff point, show a decreased survival compared with patients with low levels (35% versus 73% cumulative survival for mtDNA and 21% versus 73% for mtRNA). Multivariate analysis indicates that mtRNA is an independent predictor of 2-year survival. CONCLUSIONS: Quantification of plasma mitochondrial nucleic acids may be used to recognize patients with a poor prognosis. In advanced prostate cancer patients, mtRNA seemed the strongest predictor of overall survival and an independent prognostic factor for cancer-related death. Amplification of mitochondrial nucleic acids shows increased sensitivity and specificity over genomic DNA as diagnostic and prognostic marker in prostate cancer patients.