MacKinnon 1995.

Methods	Study design: Pretest‐post‐test control group design with random assignment. Three time points, pretest, 3 months and post‐test (the study design meets the criteria for RCT design). Duration of study: 6 months. Recruitment: Subjects existing clients of the service and asked to participate (if eligible).
Participants	Description: Caregivers and children/young adults with physical disability attending the rehabilitation centre. Setting: Augementative Communication Service at Thames Valley Children's Centre. A rehabilitation centre for children and young adults with physical disabilities serving southwestern Ontario, Canada. Inclusions: Clients must have been involved with the augmentative communication service for at least 4 months, be physically able to use a computer and modem for written communication purposes as determined by clinic staff, have had a home computer system available for at least a 3‐month period, and with a working knowledge of a word processing program. There were no specified exclusion criteria. Twenty‐five individuals met the inclusion criteria, 17 (68%) agreed to participate. 17 participants were randomised, 8 to the intervention, 9 to the control. After assignment one individual dropped out of the intervention group due to technical difficulties, leaving 16 participants, 7 in the intervention group, 9 in the control group.
Interventions	Augmentative Communication Service staff provided a communication service which included all types of communication. Intervention: Participants asked to make all of their contacts to the augmentative communication service by electronic mail via the disability information service of Canada (DISC) telecommunications system. A presentation oriented the subjects to the use of the electronic mail feature of the DISC telecommunications system. Each participant received a demonstration, a full DISC users manual and a set of reduced instructions for easy reference. A home installation visit was then conducted; operational aspects of using electronic mail were reviewed. Participants asked to make one independent contact to the augmentative communication service within 48 hours of the home installation. Study made use of the subjects' existing computer systems, which were prescribed through the Ontario government's funding system. Control: Continued to contact the augmentative communication system in their usual manner: letter,telephone, and/or site visit and did not receive any equipment to access the service. Long distance calls were covered within the project's budget to ensure that the cost of contacting the service did not deter control subjects from initiating contact.
Outcomes	Primary outcomes: Participant satisfaction with the augmentative communication service [including knowledge of and familiarity with computers and computer usage], (assessed via questionnaire at baseline, 3 months and 6 months). Overall number of contacts made (documented by staff during study period using 'Electronic Mail Client Contact Form: Part A, responses by augmentative communication service staff were recorded using 'Part B). Number of independent contacts made (documented by staff during study period using 'Electronic Mail Client Contact Form: Part A, responses by augmentative communication service staff were recorded using 'Part B). Secondary outcomes: Client and staff perceptions of the utility of the electronic mail service (assessed as part of satisfaction questionnaire, intervention group only at baseline, 3 months and 6 months).
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Report states that 'the 17 consenting individuals were randomly assigned to the experimental or control groups'. Authors informed us that names were drawn randomly by someone not involved in the research.
Allocation concealment (selection bias)	Unclear risk	No information is given in the report or by authors on the nature of concealment other than names being drawn randomly.
Blinding (performance bias and detection bias) All outcomes	High risk	Pre‐study satisfaction questionnaire administered to all subjects by research assistant not associated with the service. Staff responding to messages were not blinded to the allocation, this was confirmed by contact with authors who told us that staff interacted with all subjects as part of their day to day work. Authors state 'for procedural reasons subjects therefore were aware of their random assignment to condition at the time that they completed the first satisfaction questionnaire.' Authors state in discussion when suggesting reasons for the lack of effect of the intervention: 'initially inflated satisfaction ratings for the experimental group due to knowledge that they would be receiving the electronic mail service (a bias in the design of the study.)'
Incomplete outcome data (attrition bias) All outcomes.	High risk	An intention to treat analysis is not carried out .One intervention participant dropped out post randomisation and the reason is given; technical difficulties. The method of contact for independent contacts in the intervention group was recorded only for 24 of 32 contacts. Authors confirmed via contact that this omission was because clinicians did not specify this information on the contact forms they were required to complete.
Selective reporting (reporting bias)	Low risk	The outcomes listed in the 'procedure' section are represented in the results section.
Other bias	High risk	During the fifth month of the study the network agency (DISC) made a major change to their computer system and directions for usage had to be reissued. Some participant computers required technical/software changes.In the results the authors saw a drop in the number of independent contacts by the intervention group at the point where DISC changed the system set up and organisation. They speculate that without this interruption which involved orientation and system set up, ' a plateau might have been seen in the number of independent contacts by the experimental group as was the case for the number of contacts. Authors also state that 'the unforeseen technical problems likely affected subjects' attitudes towards electronic mail and its potential use, and may have affected the primary outcome of interest.' These unforeseen problems may feasibly have affected the effect size. Baseline comparability: Investigators measured receptive vocabulary (measured at baseline using Peabody Picture Vocabulary Test‐Revised (PPVT‐R)) and there was no significant difference between the two groups in their mean age equivalence scores. Validity of measures: PPVT‐R is a validated questionnaire. Seven references are provided on its use and adaptation for non‐speakers (of which there are 5 in the study). No information given on the satisfaction questionnaire and whether it was validated. Reliability of measures: The baseline PPVT‐R was administered face‐to face by a qualified speech/language pathologist. The patient satisfaction questionnaire was administered to all subjects by a research assistant not associated with the augmentative communication service. The satisfaction questionnaires were carried out either face‐to‐face or over telephone. The different delivery methods may have led to differing responses. Number of contacts data relies on self‐report by staff (contact forms) and this introduces a risk of bias, especially given that staff were not blinded to group allocation.