Interventions for preventing injuries in the construction industry
Abstract
This is a protocol for a Cochrane Review (Intervention). The objectives are as follows:
To determine the effectiveness of interventions designed to prevent occupational injuries among workers at construction sites.
Background
The health of construction workers is still endangered by occupational disability caused by injury. During a ten‐year follow‐up, 16% of German construction workers were granted a disability pension (Arndt 2004). Injuries were one of the major factors that lead to this high proportion of occupational disability with a standardized injury ratio of 2.52 compared with the general workforce (Arndt 2004). Poor construction safety and associated fatal and non‐fatal occupational injuries have been reported in many studies around the world, for example, the USA (Bondy 2005; Hoonakker 2005), the UK (Haslam 2005), Taiwan (Chi 2005), Australia (Larsson 2002) and the Netherlands (Lourens 2005). Fatal injury incidence rates of 4 (UK) to 11.7 (USA) per 100,000 construction workers were reported in 2003 (Dong 2004; Haslam 2005). Recent reports show a non‐fatal major injury rate of 375 per 100,000 construction workers in the UK in 2002 to 2003 (Haslam 2005) and an annual incidence rate for any injury of 10% in the Netherlands in 2004 (Lourens 2005). The majority of construction fatalities result from falls from heights and being struck by moving vehicles, while the majority of non‐fatal injuries also result from falls from heights and on the level, from slips and trips, and being struck by a moving or falling object (Bentley 2006; Haslam 2005).
The construction industry is a vital component of the economies of all countries around the world. A considerable workforce is employed in this industry. Direct workers' compensation costs due to slips and trips varied from $0.04 in insulation work to $20.56 in roofing, with an average of $4.3 per $100 payroll costs during a large construction project in the USA (Lipscomb 2006). Medical, productivity, supervisory and liability costs increase the financial losses even more (Leamon 1995; Loushine 2006). This stresses the importance of an effective health and safety policy. Effective interventions to prevent occupational injuries are the basis of an effective health and safety policy in the construction industry to ensure the health of construction workers. For illnesses due to cumulative exposures like musculoskeletal disorders, systematic reviews including the area of construction work are already available (for example, Van der Molen 2005a) or in development (for example, Martimo 2006).
Despite construction workplaces being diverse and changing over time, interventions to reduce injuries probably work in similar ways. Haslam 2005 described the following five types of interventions according to their point of action:
1. Worker and work team (causal factors like actions/behaviour; capabilities; communication; supervision; health/fatigue);
2. Workplace (causal factors like site conditions; layout; work environment; scheduling; housekeeping);
3. Materials (causal factors like suitability; usability; condition);
4. Equipment (causal factors like suitability; usability; condition);
5. Organisation (causal factors like construction design; project management; construction processes; safety culture; risk management; productivity aspects).
Various interventions to prevent occupational injuries have been proposed and studied (Becker 2001; Darragh 2004; Suruda 2002; Winn 2004). The effectiveness of the different interventions on occupational injuries, however, remains unclear (Lipscomb 2003). Several attempts have been made to summarise the effectiveness of safety interventions in reviews, but these reviews are outdated (Rivara 2000) or focused just on the prevention of one event, for example, falling from roofs (Hsiao 2001), or on one injury type (Lipscomb 2000). This review will systematically summarize the most current scientific evidence on the effectiveness of interventions to prevent all types of occupational injuries in construction work.
Objectives
To determine the effectiveness of interventions designed to prevent occupational injuries among workers at construction sites.
Methods
Criteria for considering studies for this review
Types of studies
We will include all randomized controlled trials.
In the safety field it is much more difficult to randomize participants than in clinical studies. Moreover, if the intervention is of an environmental origin, like improving working conditions at one department, it is impossible to randomize individuals. Therefore we will also include cluster‐randomized studies and controlled before and after studies (also called quasi‐experimental studies), in which participants are not randomized but deliberately allocated to the experiment and control groups. In studies of injuries, it is quite common that the outcome is automatically registered based on an obligation of the employer to notify or register all injuries of a certain type that occur. Injury studies are often conducted using administrative databases from insurance and governmental sources. These databases provide data on injury rates over a long period of time, thereby providing opportunities for measuring possible effects of interventions. If there are at least three data‐points before and three data‐points after the intervention, we will include these study designs as interrupted time series (EPOC 2006). We will base our conclusions on these study types.
In addition to the study types mentioned above, we will also search for before‐after studies without a control group and case‐reference studies. We will describe them and compare the results with the controlled studies in the discussion section.
Types of participants
The population will be limited to construction workers (employees or self‐employed). For the purposes of this study, construction workers are defined as persons working at a construction site for building/housing/residential or road/highway/civil engineering or offices/commercial or industrial installation (for example, ventilation, pipelines and siding) work. Activities of these establishments are generally managed at a fixed place of business, but they usually perform construction activities at multiple project sites. Construction work done by the workers includes new work, additions, alterations, or maintenance and repairs. These definitions are based on the North American Industry Classification System (NAICS 2002). Significant other areas of construction are refurbishment and demolition of building and engineering projects as well as plumbing, heating, ventilation and air conditioning work.
Types of interventions
All interventions aimed at preventing occupational injuries will be included in this review. To be included, work‐related injury must be an outcome in the intervention study. Five categories of interventions will be distinguished, namely interventions aimed at:
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worker and work team;
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workplace;
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materials;
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equipment;
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organisation.
Types of outcome measures
Primary outcome measures
The primary outcome measures are fatal and non‐fatal occupational injuries. We will use the following modified definition of injury, which was used in The Injury Chartbook by the World Health Organization (Baker 1984; Peden 2002);
'Non‐fatal occupational injury is a body lesion at the organic level, resulting from acute exposure to energy (mechanical, thermal, electrical, chemical or radiant) in a work environment in amounts that exceed the threshold of physiological tolerance. In some cases (for example, drowning, strangulation, freezing), the injury results from an insufficiency of a vital element.'
Traffic injuries will be included, if they are a result of commuting.
All measurements of injuries, including self‐reports, will be used.
Secondary outcome measures
If injury has been reported in an included study as a primary outcome measure, the following secondary outcomes will be used (when reported);
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Number of lost working days;
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Behaviour (changing and maintaining behaviour, for example, working habits as described by Van der Molen 2005b).
Search methods for identification of studies
We will search the following electronic databases;
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Cochrane Central Register of Controlled Trials
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Cochrane Injuries Group's specialised register
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MEDLINE
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PubMed (1966 to present),
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EMBASE (1988 to present)
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PsychINFO (1983 to present),
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OSH‐ROM (including NIOSHTIC and HSELINE)
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EI Compendex (1990 to present)
We will use search terms that cover the concepts of 'construction workers' (participants), 'injury' (primary outcome measure), 'safety' (interventions) and 'study design' to identify studies in the electronic databases. Further details of how the search strategy for the electronic databases was developed are presented in Table 1.
| Preliminary searches were done in PubMed to define useful terms for the search strategy. This revealed that searches could be made sensitive but not specific enough. We developed the definitions described below. |
We will use the following PubMed search strategy adapted as appropriate to the specifications of each database;
#1 construction*[tiab] OR building*[tw] OR builder*[tiab]OR laborer* [tw] OR labourer* [tw] OR contractor* [tw] OR supervisor*[tw] OR "machine driver"[tw] OR "machine drivers"[tw] OR "machine operator"[tw] OR "brick mason"[tw] OR "pile driver"[tw] OR "pile drivers"[tw] OR "concrete worker"[tw] OR "concrete workers"[tw] OR "metal worker"[tw] OR "metal workers"[tw] OR "road builder"[tw] OR "road builders"[tw] OR "pipe driver"[tw] OR "pipe drivers"[tw] OR "tower crane"[tw] OR fitter*[tw] OR carpenter* [tw] OR rammer* [tw] OR scaffolder* [tw] OR bricklayer* [tw] OR pointer* [tw] OR plasterer* [tw] OR plasterpainter* [tw] OR roofer* [tw] OR plumber* [tw] OR glazier* [tw] OR screeder* [tw] OR electrician* [tw] OR tiler* [tw] OR painter* [tw] OR paviour* [tw] OR pavier*[tw] OR ironwork*[tw] OR metalwork*[tw] OR asphalt*[tw] OR roofing[tw] OR painting[tw] OR "construction materials"[MeSH] OR "facility design and construction"[MeSH]
#2 injur*[tw] OR accident*[tw] OR "accidents, occupational"[MeSH] OR "wounds and injuries"[MeSH] OR harm*[tw] OR wound*[tw] OR fall[tw] OR falling*[tw] OR burn*[tw] OR slipper*[tw] OR poison*[tw] OR fatal*[tw] OR "injuries"[MeSH Subheading]
#3 Safety[MeSH] OR "Safety Management"[MeSH] OR "prevention and control"[MeSH Subheading] OR safet*[tw] OR prevent*[tw] OR control*[tw] OR risk[tiab] OR "risk"[MeSH Term] OR "risk management"[MeSH Terms] OR "accident prevention"[MeSH Terms]
#4 = #1 AND #2 AND #3
#5 (randomized controlled trial[pt] OR controlled clinical trial[pt] OR randomized controlled trials[mh] OR random allocation[mh] OR double‐blind method[mh] OR single‐blind method[mh] OR clinical trial[pt] OR clinical trials[mh] OR "clinical trial"[tw] OR ((singl*[tw] OR doubl*[tw] OR trebl*[tw] OR tripl*[tw]) AND (mask*[tw] OR blind*[tw])) OR "latin square"[tw] OR placebos[mh] OR placebo*[tw] OR random*[tw] OR research design[mh:noexp] OR comparative study[mh] OR evaluation studies[mh] OR follow‐up studies[mh] OR prospective studies[mh] OR cross‐over studies[mh] OR control*[tw] OR prospectiv*[tw] OR volunteer*[tw]) NOT (animal[mh] NOT human[mh])
#6 = #4 AND #5
#7 (effect* [tw] OR control* [tw] OR evaluation* [tw] OR program* [tw]) NOT (animal[mh] NOT human[mh])
#8 = #4 AND #7
#9 = #6 OR #8
We will also check the reference lists of relevant papers and search the following websites;
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http://www.cdc.gov/elcosh/index.html;
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http://www.pubs.asce.org/journals/jrns.html;
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http://www.hse.gov.uk/research/rrhtm/index.htm;
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http://www.inrs.fr;
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http://www.arbetslivsinstitutet.se/biblioteket/default.asp;
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http://www.hvbg.de/d/bia/pub/ueb/index.html.
The searches will not be restricted by language or publication status.
Data collection and analysis
Study identification and selection
The selection of studies will be carried out independently by two authors (ML and HM) according to the inclusion and exclusion criteria. Any disagreement about the inclusion of studies will be followed by a discussion until consensus is reached between the two authors. In case of persistent disagreement, a third author will (JL) decide. If the title and abstract provide sufficient information to decide that the criteria for selection will not be satisfied, the study will be excluded. The full articles of the remaining studies will be then examined by the two authors in order to decide which studies fulfil the criteria for selection. The reasons for exclusion will be documented. The information in articles in languages other than English will be abstracted and translated by a native speaker.
Data extraction and management
Data will be extracted independently by two authors (ML and HM). In case of disagreement, a third author (JL) will decide. A form will be developed to extract the following data from the articles:
Study design;
‐ (cluster) randomized controlled trial, controlled before and after study, interrupted time series.
Participants ;
‐ number, trade, age, gender, exposure.
Intervention ;
‐ target (for example, worker and work team or workplace or materials or equipment or organisation),
‐ form (for example, information, compulsion, education, facilitation, persuasion),
‐ content (for example, intervention in control group).
Outcome;
‐ primary and secondary outcome, methods used to assess outcome measures, duration of follow‐up.
Setting (in what kind of work setting was the intervention carried out);
‐ size of the company, culture, country, industry sub‐sector (type of construction work as mentioned in inclusion criteria), trade, and job.
Assessment of methodological quality of included studies
The quality of the included studies will be independently assessed by two authors (ML and HM). Since we expect that most of the studies available will be non‐randomized we will use the Downs and Black (Downs 1998) quality checklist that is capable of assessing both randomized and non‐randomized studies. We will use the scale on internal validity from the checklist to rank studies according to quality. Any disagreement about the quality assessment of studies will be followed by a discussion until consensus is reached between the two authors. In case of persistent disagreement, a third author (JL) will decide. For interrupted time‐series studies we will use the quality criteria as developed by the EPOC review group (EPOC 2006).
Measures of intervention effect
All relevant effect measures will be included. Typically the intervention effect is measured using an injury rate, such as number of injuries per 100 person‐years. The results of each trial will be plotted as point estimates, such as relative risk (RR) or odds ratio (OR) for dichotomous outcomes or other data types as reported by the authors of the studies. When the results cannot be plotted, they will be described in the table of included studies, or the data will be entered into 'other data tables'.
Unit of analysis issues
Individual outcomes will be analysed. If we encounter cluster randomized controlled trials that did not take into account the effect of clustering we will make the appropriate statistical corrections.
Dealing with missing data
Missing data will be sought from authors. Meta‐analysis will be conducted if available studies are sufficiently similar with respect to participants, interventions and outcomes.
In case of missing data the procedures described in the Cochrane Handbook for Systematic Reviews of Interventions (Higgins 2005) will be used to assess quality.
Assessment of heterogeneity
Methodological heterogeneity will be assessed with respect to research setting, applied interventions, study design and population. Statistically heterogeneity will be examined with the I2 test (notable heterogeneity when I2 > 60%).
In the case of methodological and statistical homogeneity, a meta‐analysis with a random effects model will be applied.
Data synthesis (meta analysis)
A meta‐analysis will only be conducted if the available studies are sufficiently similar with respect to participants, interventions and outcomes. A qualitative analysis will be completed if the studies are found to be clinically heterogeneous, or if the relevant data to complete statistical pooling are unavailable.
A rating system, based on the Levels of Evidence, will be used to summarize the strength of scientific evidence of the effects of the intervention. The rating system will be based on both the quality and the outcome of the studies (Van Tulder 2003):
I. Strong evidence ‐ consistent evidence in multiple high quality randomized controlled trials or controlled trials;
II. Moderate evidence ‐ consistent findings in multiple low quality randomized controlled trials, controlled trials, interrupted time series and/or one high quality randomized controlled trial;
III. Limited evidence ‐ one low quality randomized controlled trial or controlled trial or interrupted time series;
IV. Conflicting evidence ‐ inconsistent findings in multiple trials;
V. No evidence ‐ no trials.
The outcome of the studies will be considered 'consistent' if at least 75% of the trials report statistically significant results in the same direction. For a sensitivity analysis, the results will be analysed again, including only high quality studies, to find out if quality level leads to changes.
Subgroup analyses
If sufficient data are available, we will perform subgroup analyses according to participants, interventions or settings as listed in the 'Data extraction and management' section. We will do so, because safety policy and culture can vary between work places according to worker and setting characteristics.
| Preliminary searches were done in PubMed to define useful terms for the search strategy. This revealed that searches could be made sensitive but not specific enough. We developed the definitions described below. |
