Condition category
Mental and Behavioural Disorders
Date applied
27/02/2017
Date assigned
03/03/2017
Last edited
02/03/2017
Prospective/Retrospective
Retrospectively registered
Overall trial status
Ongoing
Recruitment status
No longer recruiting

Plain English Summary

Background and study aims
The aim of this study is to find out whether “greening” vacant land to create little parks near where people live, improves people’s health and safety. Vacant lots are in great abundance, are singled out by community members as important, and are highly modifiable, with the potential for sustained, long-term health and safety benefits at relatively little cost. In 1999, the Pennsylvania Horticultural Society began a program to stabilize and maintain vacant lots in key Philadelphia neighbourhoods. This study tests the impact of such a program on public substance (drug) use, drinking and related behaviours.

Who can participate?
English and Spanish speaking people aged 19 and over who live in four areas of Philadelphia

What does the study involve?
420 vacant lots in four areas of Philadelphia are randomly allocated into three groups. The first group of vacant lots undergo stabilization, which involves “cleaning and greening” by removing trash and debris, grading the land, planting grass and a small number of trees to create a park-like setting, and installing low wooden perimeter fences to show that the lot is cared for and deter illegal dumping. This is carried out by well-coordinated teams of workers, many of whom come from local urban neighbourhoods, along with regular monthly maintenance of treated lots including grass cutting, tree pruning, fence repair, and trash clean-up. The second group of vacant lots undergo trash clean-up only, which involves removing trash and debris, mowing existing grass on the lot, and regular monthly maintenance including continued grass cutting and trash clean-up. The third group of vacant lots do not undergo stabilization or clean-up. Substance abuse, drinking and related health and safety outcomes on or near the lots are measured in the years before and after the intervention using data collected from the local police and by interviewing local residents about their health. The cost-effectiveness of vacant lot stabilization is also calculated.

What are the possible benefits and risks of participating?
The benefits of participating in this study are access to a newly created local park and contributing to a better understanding of the value of greenery and parks in cities. The risks of participating are minimal.

Where is the study run from?
1. University of Pennsylvania (USA)
2. Columbia University (USA)

When is the study starting and how long is it expected to run for?
February 2011 to January 2018

Who is funding the study?
1. National Institutes of Health (USA)
2. Centers for Disease Control and Prevention (USA)

Who is the main contact?
Dr Charles Branas

Trial website

Contact information

Type

Scientific

Primary contact

Dr Charles Branas

ORCID ID

Contact details

Columbia University
Mailman School of Public Health
722 West 168th Street
Rm 1508
New York NY USA 10032
New York
10032
United States of America

Additional identifiers

EudraCT number

ClinicalTrials.gov number

Protocol/serial number

R01AA020331

Study information

Scientific title

A randomized trial of urban vacant lot stabilization and substance abuse outcomes

Acronym

Study hypothesis

1. The stabilization of randomly chosen vacant lots will change the public occurrence of illegal drug trafficking and consumption compared with vacant lots that have been randomly chosen to receive only trash clean-up and lots that have been randomly chosen to receive nothing.
2. The stabilization of randomly chosen vacant lots changes the public occurrence of illegal drunkenness and drinking compared with vacant lots that have been randomly chosen to receive only trash clean-up and lots that have been randomly chosen to receive nothing.
3. The incremental cost-effectiveness of vacant lot stabilization will be high in terms of the cost of vacant lot stabilization per instances of illegal drug trafficking and consumption and illegal public drunkenness and drinking avoided.

Ethics approval

University of Pennsylvania Institutional Review Board, 14/07/2015, ref: 816097

Study design

Controlled parallel-group cluster randomized trial

Primary study design

Interventional

Secondary study design

Cluster randomised trial

Trial setting

Community

Trial type

Prevention

Patient information sheet

No participant information sheet available

Condition

Substance abuse

Intervention

420 vacant lots stratified in four geographic sections of Philadelphia are randomised into three trial arms:
1. Vacant lot stabilization (full treatment)
2. Trash clean-up only (trash control)
3. No vacant lot stabilization or clean-up (no treatment).

The first intervention tested involves the “cleaning and greening” of vacant lots via a standard, reproducible process of removing trash and debris, grading the land, planting grass and a small number of trees to create a park-like setting, and installing low wooden perimeter fences to show that the lot is cared for and deter illegal dumping. This intervention is completed via a well-coordinated teams of workers, many of whom come from local urban neighborhoods affected by vacant land, and an economical grass hydroseeding method that can quickly seed large areas of land by spraying a slurry mixture of seed and mulch. The intervention additionally includes regular monthly maintenance of treated lots including grass cutting, tree pruning, fence repair, and trash cleanup.

A second, simpler vacant lot intervention is also tested that is a standard, reproducible process of removing trash and debris, mowing existing grass on the lot, and regular monthly maintenance including continued grass cutting and trash cleanup.

Both interventions are performed for all study vacant lots to which they are randomly assigned over a two-month period from 01/04/2013 to 31/05/2013.

Both area-wide outcome measures in and around each cluster, as well as participant-level outcome measures are collected and analyzed. Violence and crime data are collected from local police and aggregated by month for 18 pre-intervention months and 18 post-intervention months, for a total of 36 observation periods. These data include the dates and address locations of six outcomes: gun assaults, nongun assaults, burglaries, robberies and thefts, narcotics possession, sales, and trafficking, and nuisances. Nuisances are defined as the summation of curfew violations, disorderly conduct, public drunkenness, illegal dumping, loitering, noise violations, prostitution, and vandalism. The address location of each violence and crime event is geographically assigned to a point-in-space and a kernel density estimate is used to calculate events per square mile for all outcomes at the centroid points representing each vacant lot.

Perceptions of violence, crime, nuisances, and safety are surveyed from participants. The same questions are asked to all participants across all 4 waves of the survey at 2 time points at baseline and at 2 time points post-intervention. Participants are asked to focus their responses to their experiences within the past 30 days to avoid telescoping and over-estimation by participants. Various approaches are used to measure participant-reported outcomes: visual analog scales, Likert scales, and binary true/false questions.

Intervention type

Other

Phase

Drug names

Primary outcome measures

Illegal drug trafficking and consumption, measured using data collected from local police and aggregated by month for 18 pre-intervention months and 18 post-intervention months

Secondary outcome measures

Illegal drunkenness and drinking, measured using data collected from local police and aggregated by month for 18 pre-intervention months and 18 post-intervention months

Overall trial start date

10/02/2011

Overall trial end date

31/01/2018

Reason abandoned

Eligibility

Participant inclusion criteria

Randomly sampled English and Spanish speaking individuals, aged 19 years and older, who lived within the clusters

Participant type

Healthy volunteer

Age group

Adult

Gender

Both

Target number of participants

450

Participant exclusion criteria

Non-English, non-Spanish speaking, not residents living within clusters

Recruitment start date

01/10/2011

Recruitment end date

01/11/2014

Locations

Countries of recruitment

United States of America

Trial participating centre

University of Pennsylvania
Philadelphia
19104
United States of America

Trial participating centre

Columbia University
New York
10032
United States of America

Sponsor information

Organisation

National Institutes of Health

Sponsor details

9000 Rockville Pike
Bethesda
20892
United States of America

Sponsor type

Government

Website

Organisation

Centers for Disease Control and Prevention

Sponsor details

1600 Clifton Road
Atlanta
30329
United States of America

Sponsor type

Government

Website

Funders

Funder type

Government

Funder name

National Institutes of Health (ref: R01AA020331)

Alternative name(s)

NIH

Funding Body Type

government organisation

Funding Body Subtype

federal/national government

Location

United States of America

Funder name

Centers for Disease Control and Prevention (ref: R49CE002474)

Alternative name(s)

CDC

Funding Body Type

government organisation

Funding Body Subtype

federal/national government

Location

United States of America

Results and Publications

Publication and dissemination plan

Planned publication in a high-impact peer reviewed journal one year after the trial ends.

IPD sharing plan
The current data sharing plans for the current study are unknown and will be made available at a later date.

Intention to publish date

31/01/2019

Participant level data

To be made available at a later date

Results - basic reporting

Publication summary

Publication citations

Additional files

Editorial Notes