The following three data transmission models were developed for countries to adapt to their specific needs:

• Model A - Web-based data transmission: This model (Figure 2.2) was designed for countries with experience in electronic data collection systems and a wide reach of access to wireless Internet, which was considered a relatively high level of infrastructure and technical capacity. The sample was loaded onto the handheld computers from the national center to the field via wireless Internet using a Web interface and the data from the field were transmitted back to the national data center using the handheld devices and wireless Internet connections. Of the 14 countries, only one (Poland) implemented GATS using the Web-based data transmission model [Table 1].

[Figure ID: f2.2-ojphi-04-12] Figure 2.2: 

Model A – Web-based transmission



• Model B - Combination of Web and card based: This model (Figure 2.3) was designed for countries that did not fit the Model A requirements but had field Internet capabilities similar to most countries, which was considered an intermediate level of infrastructure and technical capacity. The data were transmitted using Secure Digital (SD) cards for loading the sample from the national level to the field level and over the Internet from the field to the national level, either via email or secure File Transfer Protocol (FTP) sites. All countries other than Poland used Model B, either fully or partially, for data management of GATS [Table 1].

[Figure ID: f2.3-ojphi-04-12] Figure 2.3: 

Model B – Card –based with field Internet capabilities



• Model C - Card-based data transmission: This model (Figure 2.4) was designed for countries with no Internet access, considered the weakest level of infrastructure and technical capacity. The data were transmitted manually in both directions using SD cards, from the national center to the field interviewer’s portable handheld computers and back, or in some cases via FTP file transfers. None of the 14 countries used this model exclusively; China and Egypt used a combination of Models B and C for some areas with very poor infrastructure and no Internet access [Table 1].

[Figure ID: f2.4-ojphi-04-12] Figure 2.4: 

Model C: Card-based data transmission

For the first phase, two main models of HP IPAQ® portable handheld computers were used for data collection in most countries. The HP IPAQ hx2490c was used initially and then after it went out of production, the HP IPAQ 210/211 series was used.

The hardware was procured centrally to avoid country-specific procurement delays. Each portable handheld computer was accompanied with two SD cards and one extra battery as backup. Brazil used already existing handhelds with the Windows 5 operating system, which had been used for previous surveys [¹²]. A 10% hardware contingency was provided. After the completion of data collection, the handheld computers and other equipment were donated and remained in each country, so that both hardware and software could be reused to conduct other research or surveys as needed.

The General Survey System (GSS) used in GATS is open-source software, which meant it could be used for data collection in any national or sub-national surveys. The database was stored on the handheld computers in an encrypted Structured Query Language (SQL) Server, compact edition database file (SDF) format. GSS had two main components, as described below:

A standardized training mechanism was used for training in-country IT/fieldwork personnel. The data management team was extensively trained on each component of the survey system so they could train fieldwork personnel and maintain GATS specific data collection and quality control procedures. This also insured that countries would be able to conduct future surveys/research using the software and hardware. The training package consisted of three main components:

1. Training for pre-test and full survey implementation: Each country conducted a pretest prior to the actual fieldwork to test the data management model, software and hardware system, and questionnaire used in GATS, in order to extract lessons for effectively and systematically implementing the full survey. The training, ranging from three to five days, was provided to the country implementation team, IT and data management teams, and fieldwork personnel, using standardized training procedures with a specific focus on data collection and management with handheld devices [⁸]. In some countries (e.g., Bangladesh), refresher training was conducted in addition to the full survey training to meet country-specific needs and address changes in the data collection implementation mechanism. Other countries (e.g., Russia) were able to conduct the full survey with remote support after the in-country pre-test training.
2. Manuals and guides: Specific manuals for data management were developed and adapted for each country as needed. These followed the standard protocol and were an important instrument for maintaining systematic and standard procedures, as well as sustaining capacity. They included:
   • Programmer’s Guide to the General Survey System [²⁶]
   • Core Questionnaire Programming Specifications [²⁷]
   • Data Management Implementation Plan [²⁸]
3. Technical support: An ongoing support mechanism via an international team of technical experts was in place to manage any challenges in the large-scale field implementation and provide remote and in-country technical knowledge for all countries.

Paper-based systems have been used for a long time in developing countries, but with many quality issues, such as transcription, data entry, and editing errors, skip logic errors, out-of-range values, and recording of ambiguous values. This has been especially true where the interviewer had to refer to answers to previous questions (sometimes in previous sections) in order to determine what question to ask next, based on the logical flow of the questionnaire. These errors were usually found during data entry from the paper forms and edited out with a good data entry and cleaning program, however it was difficult to rectify them at the entry level. The use of portable handheld computers allowed quality control at the time of data capture while the respondent was still present. The use of skip programming, range checks, validation and other data checks for valid data entry on portable handheld computers has proven to be highly instrumental in enabling high data quality and standardized entry at the collection stage. In-built skip and logic checks increased efficiency and reduced interview time.

In GATS, the data were stored digitally on the handheld computer and backed up on an external memory card, thus no data entry was required at the end of the survey. The data were transmitted during fieldwork, using the Web or emails on a daily or weekly basis, allowing early monitoring and quality control of the fieldwork at the regional and/or national level, which was not easily possible in paper-based surveys.

Overall the electronic data collection mechanism enabled better data quality control, as the data were verified at the entry level from the original data sources. In addition, rapid availability of the electronic files made early monitoring and review possible.

Use of portable handheld computers in GATS proved to be both time- and cost-effective. It also reduced error during risk-prone processes, such as administration of a huge number of paper questionnaires, shipping the equipment, and data entry and data cleaning.

Based on feedback from the countries, the fieldwork was usually slower than average in the first two weeks, as fieldworkers learned to use the technology. However over time the pace picked up and overall timing actually improved by the end of the survey. Most countries completed their fieldwork on or before the scheduled end date.

The process was reported to be more efficient and timely overall as compared to paper and pencil methods. One reason was the much reduced manual work required during interviews when using fully programmed electronic questionnaires. The automated data checks also saved interviewing time and costs.

Decreasing the time between data collection and data reporting had many advantages. It reduced costs, allowed better tracking of survey completions, helped estimate time to project completion, promoted early analysis, and allowed issues with questionnaires to be reported and corrected more swiftly. Electronic data capture reduced the time between data collection and reporting by putting the data in a clean, electronic format as soon as they were collected. GATS showed that electronic data collection could be optimally efficient for large-scale activities, given the rapid availability of data for reporting, analysis and prompt action.

The portable handheld computers were easy to use and carry. The electronic data collection system using portable handheld computers proved to be very manageable administratively over the entire span of the data collection, especially for large-scale surveys.

A 10% hardware contingency was planned, however, the actual hardware failure rate GATS was less than 1%. Battery life, which was an early concern, proved not to be a problem in the field as the instructions to charge the equipment every night were followed and monitored, and there was proper advance planning, especially for fieldwork in remote and rural areas.

Handheld computers provided a more secure environment for data because they were validated and stored electronically at the entry stage, with backup on the device as well on an SD card in a secure encrypted format. This ensured safety, security and anonymity of the data.

The electronic data collection system used in GATS resulted in 0% data loss globally. It provided an accurate and stringent audit trail of response recording, which facilitated early monitoring of data integrity issues at the field level, highlighting any unconventional changes in data values.

The initial cost to purchase equipment was a prominent budget item. It seemed likely that the use of handheld computers would be cost effective only if they were used for multiple surveys or other data collection initiatives.

Although the initial cost of equipment was higher, there were other major areas of cost savings, including paper, printing, and dispatch and handling of paper questionnaires, in addition to savings associated with data entry software purchases, data entry forms programming and development, and labor costs for data entry and editing. The entry-level checks with enhanced data quality may have provided greater precision with smaller sample sizes, compared to paper-based systems where the data cleaning removes invalid data thus requiring additional data to achieve similar precision. Overall this methodology allowed for faster data availability, enhanced data quality, and reduced administrative and logistical efforts and costs. The higher up-front costs of the electronic systems were recovered or mitigated by reducing back-end costs (e.g., keying and editing) and speeding up access to the data for analysis. In addition, it improved data quality.

It was expected that a significant issue in using handheld computers for GATS would be the initial training and technical support. This was addressed by adding additional one or two days of structured training for interviewers in the use of handheld computers for data collection. Although this was an extra initial cost, one day of extra training time was gained because less training was needed on questionnaire skips and quality checks, as these were built into the system. Any extra time and cost was easily compensated by the faster fieldwork using electronic data collection.

The GATS partners facilitated significant technical capacity building at the country level in the implementation of nationally representative surveys. Sustainable technical skills and the electronic data collection and management system together have proven to simplify and shorten the data collection process, enhance data quality and facilitate Health System Strengthening at the country level. This has been demonstrated by GATS countries having subsequently successfully conducted other national or health surveys using the new system (e.g., Egypt used the system for an economic survey, Bangladesh used the portable handheld computers for a non-communicable disease risk factor survey, China used a similar system for its Behavioral Risk Factor Survey, and India has conducted a national feasibility review for implementing this system across all health surveys in that country).