Thursday, 27 October 2011 20:06

Case Study: A Summary of Studies of Reproductive Outcomes

Rate this item
(1 Vote)

In a case-control study looking at environmental and occupational factors for congenital malformations (Kurppa et al. 1986), 1,475 cases were identified from the Finnish Register of Congenital Malformations during the period between 1976 and 1982 (see table 1). A mother whose delivery immediately preceded a case, and was in the same district, served as a control for that case. Exposure to visual display units (VDUs) during the first trimester of pregnancy was assessed using face-to-face interviews conducted either at the clinic during a post-natal visit, or at home. The classification of probable or obvious VDU use was determined by occupational hygienists, blind to the pregnancy outcomes, using job titles and the responses to open-ended questions asking to describe the ordinary work day. There was no evidence of increased risk either among women who reported exposure to VDUs (OR 0.9; 95% CI 0.6 – 1.2), or among women whose job titles indicated possible exposure to VDUs (235 cases/255 controls).

A cohort of Swedish women from three occupational groups was identified through a linkage of occupational census and the Medical Birth Registry during 1980–1981 (Ericson and Källén 1986). A case-base study was conducted within that cohort: cases were 412 women hospitalized for spontaneous abortion and an additional 110 with other outcomes (such as perinatal death, congenital malformations and birthweight below 1500 g). Controls were 1,032 women of similar age who had infants without any of these characteristics, chosen from the same registry. Using crude odds ratios, there was an exposure–response relation between VDU exposure in estimated hours per week (divided into five-hour categories) and pregnancy outcomes (excluding spontaneous abortion). After controlling for smoking and stress, the effect of VDU use on all adverse pregnancy outcomes was not significant.

Focusing on one of three occupational groups identified from a previous study by Ericson a cohort study was conducted using 4,117 pregnancies among social security clerks in Sweden (Westerholm and Ericson 1986). Rates of hospitalized spontaneous abortion, low birthweight, perinatal mortality and congenital malformations in this cohort were compared to rates in the general population. The cohort was divided into five exposure groups defined by trade union and employer representatives. No excesses were found for any of the studied outcomes. The overall relative risk for spontaneous abortion, standardized for mothers’ age was 1.1 (95% CI 0.8 – 1.4).

A cohort study involving 1,820 births was conducted among women having ever worked at the Norwegian Postal Giro Centre between 1967–1984 (Bjerkedal and Egenaes 1986). The rates of stillbirth, first-week death, perinatal death, low and very low birthweight, preterm birth, multiple births and congenital malformations were estimated for pregnancies occurring during employment at the centre (990 pregnancies), and pregnancies occurring before or after employment at the centre (830 pregnancies). Rates of adverse pregnancy outcomes were also estimated for three six-year periods, (1967–1972), (1973–1978) and (1979–1984). Introduction of VDUs began in 1972, and were extensively used by 1980. The study concluded that there was no indication that introduction of VDUs in the centre had led to any increase in the rate of adverse pregnancy outcomes.

A cohort of 9,564 pregnancies was identified through logs of urine pregnancy tests from three California clinics in 1981–1982 (Goldhaber, Polen and Hiatt. 1988). Coverage by a Northern California medical plan was a requirement to be eligible for the study. Pregnancy outcomes were found for all but 391 identified pregnancies. From this cohort, 460 of 556 spontaneous abortion cases (<28 weeks), 137 of 156 congenital abnormality cases and 986 of 1,123 controls (corresponding to every fifth normal birth in the original cohort), responded to a retrospective postal questionnaire on chemical environmental exposures including pesticides and VDU use during pregnancy. Odds ratios for women with first trimester VDU use over 20 hours per week, adjusted for eleven variables including age, previous miscarriage or birth defect, smoking and alcohol, were 1.8 (95% CI 1.2 – 2.8) for spontaneous abortion and 1.4 (95% CI 0.7 – 2.9) for birth defects, when compared to working women who did not report using VDUs.

In a study conducted in 11 hospital maternity units in the Montreal area over a two-year period (1982–1984), 56,012 women were interviewed on occupational, personal and social factors after delivery (51,855) or treatment for spontaneous abortion (4,127) (McDonald et al. 1988).These women also provided information on 48,637 previous pregnancies. Adverse pregnancy outcomes (spontaneous abortion, stillbirth, congenital malformations and low birthweight) were recorded for both current and previous pregnancies. Ratios of observed to expected rates were calculated by employment group for current pregnancies and previous pregnancies. Expected rates for each employment group were based on the outcome in the whole sample, and adjusted for eight variables, including age, smoking and alcohol. No increase in risk was found among women exposed to VDUs.

A cohort study comparing rates of threatened abortion, length of gestation, birthweight, placental weight and pregnancy-induced hypertension between women who used VDUs and women who did not use VDUs was carried out among 1,475 women (Nurminen and Kurppa 1988).The cohort was defined as all non-cases from a previous case-control study of congenital malformations. Information about risk factors was collected using face-to-face interviews. The crude and adjusted rate ratios for the outcomes studied did not show statistically significant effects for working with VDUs.

A case-control study involving 344 cases of hospitalized spontaneous abortion occurring at three hospitals in Calgary, Canada, was conducted in 1984–1985 (Bryant and Love 1989). Up to two controls (314 prenatal and 333 postpartum) were chosen among women having delivered or susceptible of delivering at the study hospitals. The controls were matched to each case on the basis of age at last menstrual period, parity, and intended hospital of delivery. VDU use at home and at work, before and during pregnancy, was determined through interviews at the hospitals for postnatal controls and spontaneous abortion, and at home, work, or the study office for prenatal controls. The study controlled for socioeconomic and obstetric variables. VDU use was similar between the cases and both the prenatal controls (OR=1.14; p=0.47) and postnatal controls (OR=0.80; p=0.2).

A case-control study of 628 women with spontaneous abortion, identified through pathology specimen submissions, whose last menstrual period occurred in 1986, and 1,308 controls who had live births, was carried out in one county in California (Windham et al. 1990). The controls were randomly selected, in a two-to-one ratio, among women matched for date of last menstrual period and hospital. Activities during the first 20 weeks of pregnancy were identified through telephone interviews. The participants were also asked about VDU use at work during this period. Crude odds ratios for spontaneous abortion and VDU use less than 20 hours per week (1.2; 95% CI 0.88 – 1.6), and at least 20 hours per week (1.3; 95% CI 0.87 – 1.5), showed little change when adjusted for variables including employment group, maternal age, prior foetal loss, alcohol consumption and smoking. In a further analysis among the women in the control group, risks for low birthweight and intrauterine growth retardation were not significantly elevated.

A case-control study was conducted within a study base of 24,352 pregnancies occurring between 1982 and 1985 among 214,108 commercial and clerical employees in Denmark (Brandt and Nielsen 1990). The cases, 421 respondents among the 661 women who gave birth to children with congenital abnormalities and who were working at the time of pregnancy, were compared to 1,365 respondents among the 2,252 randomly selected pregnancies among working women. Pregnancies, and their outcomes, and employment were determined through a linkage of three databases. Information on VDU use (yes/no/hours per week), and job-related and personal factors such as stress, exposure to solvents, life-style and ergonomic factors were determined through a postal questionnaire. In this study, the use of VDUs during pregnancy was not associated with an increased risk of congenital abnormalities.

Using the same study base as in the previous study on congenital abnormalities (Brandt and Nielsen 1990) 1,371 of 2,248 women whose pregnancies ended in a hospitalized spontaneous abortion were compared to 1,699 randomly selected pregnancies (Nielsen and Brandt 1990). While the study was carried out among commercial and clerical workers, not all of the pregnancies corresponded to times when the women were gainfully employed as commercial or clerical workers. The measure of association used in the study was the ratio of the rate of VDU use among women with a spontaneous abortion to the rate of VDU use among the sample population (representing all pregnancies including those ending in spontaneous abortion). The adjusted rate ratio for any exposure to VDU and spontaneous abortion was 0.94 (95% CI 0.77 – 1.14).

A case-control study was carried out among 573 women who gave birth to children with cardiovascular malformations between 1982 and 1984 (Tikkanen and Heinonen 1991). The cases were identified through the Finnish register of congenital malformations. The control group consisted of 1,055 women, randomly selected among all hospital deliveries during the same time period. VDU use, recorded as never, regular or occasional, was assessed through an interview conducted 3 months after the delivery. No statistically significant association was found between VDU use, at work or at home, and cardiovascular malformations.

A cohort study was carried out among 730 married women who reported pregnancies between 1983 and 1986 (Schnorr et al. 1991). These women were employed as either directory assistance operators or as general telephone operators at two telephone companies in eight southeastern states in the United States. Only the directory assistance operators used VDUs at work. VDU use was determined through company records. Spontaneous abortion cases (foetal loss at 28 weeks’ of gestation or earlier) were identified through a telephone interview; birth certificates were later used to compare women’s reporting with pregnancy outcomes and when possible, physicians were consulted. Strengths of electric and magnetic fields were measured at very low and extremely low frequencies for a sample of the workstations. The VDU workstations showed higher field strengths than those not using VDUs. No excess risk was found for women who used VDUs during the first trimester of pregnancy (OR 0.93; 95% CI 0.63 – 1.38), and there was no apparent exposure–response relation when looking at time of VDU use per week.

A cohort of 1,365 Danish commercial and clerical workers who were gainfully employed at the time of pregnancy, and identified through a previous study (Brandt and Nielsen 1990; Nielsen and Brandt 1990), was used to study fecundability rates, in relation to VDU use (Brandt and Nielsen 1992). Fecundability was measured as time from stopping birth control use to time of conception, and was determined through a postal questionnaire. This study showed an increased relative risk for prolonged waiting to pregnancy for the subgroup with at least 21 weekly hours of VDU use. (RR 1.61; 95% CI 1.09 – 2.38).

A cohort of 1,699 Danish commercial and clerical workers, consisting of women employed and unemployed at the time of pregnancy, identified through the study reported on in the previous paragraph, was used to study low birthweight (434 cases), preterm birth (443 cases), small for gestational age (749 cases), and infant mortality (160 cases), in relation to VDU use patterns (Nielsen and Brandt 1992). The study failed to show any increased risk for these adverse pregnancy outcomes among women with VDU use.

In a case-control study, 150 nulliparous women with clinically diagnosed spontaneous abortion and 297 nulliparous working women attending a hospital in Reading, England for antenatal care between 1987 and 1989 were interviewed (Roman et al. 1992). The interviews were conducted face to face at the time of their first antenatal visit for the controls, and three weeks after the abortion for women with spontaneous abortion. For women who mentioned VDU use, estimates of time of exposure in hours per week, and calendar time of first exposure were assessed. Other factors such as overtime, physical activity at work, stress and physical comfort at work, age, alcohol consumption and previous miscarriage were also assessed. Women who worked with VDUs had an odds ratio for spontaneous abortion of 0.9 (95% CI 0.6 – 1.4), and there was no relation with the amount of time spent using VDUs. Adjusting for other factors such as maternal age, smoking, alcohol and previous spontaneous abortion did not alter the results.

From a study base of bank clerks and clerical workers in three companies in Finland, 191 cases of hospitalized spontaneous abortion and 394 controls (live births) were identified from Finnish medical registers for 1975 to 1985 (Lindbohm et al. 1992). Use of VDUs was defined using workers’ reports and company information. Magnetic field strengths were retrospectively assessed in a laboratory setting using a sample of the VDUs which had been used in the companies. The odds ratio for spontaneous abortion and working with VDUs was 1.1 (95% CI 0.7 – 1.6). When VDU users were separated in groups according to the field strengths for their VDU models, the odds ratio was 3.4 (95% CI 1.4 – 8.6) for workers who had used VDUs with a high magnetic field strength in the extremely low frequency bandwidth (0.9 μT), compared to those working with VDUs with field strength levels below the detection limits (0.4 μT). This odds ratio changed only slightly when adjusted for ergonomic and mental work-load factors. When comparing workers exposed to high magnetic field strengths to workers not exposed to VDUs, the odds ratio was no longer significant.

A study, looking at adverse pregnancy outcomes and fertility, was carried out among female civil servants working for the British Government tax offices (Bramwell and Davidson 1994). Of the 7,819 questionnaires mailed in the first stage of the study, 3,711 were returned. VDU use was determined through this first questionnaire. Exposure was assessed as hours per week of VDU use during pregnancy. One year later, a second questionnaire was sent out to assess the incidence of adverse pregnancy outcomes among these women; 2,022 of the original participants responded. Possible confounders included pregnancy history, ergonomic factors, job stressors, caffeine, alcohol, cigarette and tranquillizer consumption. There was no relationship between exposure as assessed one year previously and the incidence of adverse pregnancy outcomes.

 

Back

Read 8134 times Last modified on Tuesday, 08 November 2011 00:08
More in this category: « Ergonomics Standards

" DISCLAIMER: The ILO does not take responsibility for content presented on this web portal that is presented in any language other than English, which is the language used for the initial production and peer-review of original content. Certain statistics have not been updated since the production of the 4th edition of the Encyclopaedia (1998)."

Contents

Visual Display Units References

Akabri, M and S Konz. 1991. Viewing distance for VDT work. In Designing For Everyone, edited by Y Queinnec and F Daniellou. London: Taylor & Francis.

Apple Computer Co. 1987. Apple Human Interface Guidelines. The Apple Desktop Interface. Waltham, Mass.: Addison-Wesley.

Amick, BC and MJ Smith. 1992. Stress, computer-based work monitoring and measuring systems: A conceptual overview. Appl Ergon 23(1):6-16.

Bammer, G. 1987. How technologic change can increase the risk of repetitive motions injuries. Seminars Occup Med 2:25-30.

—. 1990. Review of current knowledge -Musculoskeletal problems. In Work With Display Units 89: Selected Papers from the Work with Display Units Conference, September 1989, Montreal, edited by L Berlinguet and D Berthelette. Amsterdam: North Holland.

Bammer, G and B Martin. 1988. The arguments about RSI: An examination. Community Health Stud 12:348-358.

—. 1992. Repetition strain injury in Australia: Medical knowledge, social movement and de facto partisanship. Social Prob 39:301-319.

Bastien, JMC and DL Scapin. 1993. Ergonomic criteria for the evaluation of human-computer interfaces. Technical Report no. 156, Programme 3 Artificial Intelligence, cognitive systems, and man-machine interaction. France: INRIA.

Berg, M. 1988. Skin problems in workers using visual display terminals: A study of 201 patients. Contact Dermat 19:335-341.

—-. 1989. Facial skin complaints and work at visual display units. Epidemiological, clinical and histopathological studies. Acta Derm-Venereol Suppl. 150:1-40.

Berg, M, MA Hedblad, and K Erkhardt. 1990. Facial skin complaints and work at visual display units: A histopathological study. Acta Derm-Venereol 70:216-220.

Berg, M, S Lidén, and O Axelson. 1990. Skin complaints and work at visual display units: An epidemiological study of office employees. J Am Acad Dermatol 22:621-625.

Berg, M, BB Arnetz, S Lidén, P Eneroth, and A Kallner. 1992. Techno-stress, a psychophysiological study of employees with VDU-associated skin complaints. J Occup Med 34:698-701.

Bergqvist, U. 1986. Pregnancy and VDT work -An evaluation of the state of the art. In Work With Display Units 86: Selected Papers from the International Scientific Conference On Work With Display Units, May 1986, Stockholm, edited by B Knave and PG Widebäck. Amsterdam: North Holland.

Bikson, TK. 1987. Understanding the implementation of office technology. In Technology and the Transformation of White-Collar Work, edited by RE Kraut. Hillsdale, NJ: Erlbaum Associates.

Bjerkedal, T and J Egenaes. 1986. Video display terminals and birth defects. A study of pregnancy outcomes of employees of the Postal-Giro-Center, Oslo, Norway. In Work With Display Units 86: Selected Papers from the Interantional Scientific Conference On Work With Display Units, May 1986, Stockholm, edited by B Knave and PG Widebäck. Amsterdam: North Holland.

Blackwell, R and A Chang. 1988. Video display terminals and pregnancy. A review. Brit J Obstet Gynaec 95:446-453.

Blignault, I. 1985. Psychosocial aspects of occupational overuse disorders. Master of Clinical Psychology Thesis, Department of Psychology, The Australian National University, Canberra ACT.

Boissin, JP, J Mur, JL Richard, and J Tanguy. 1991. Study of fatigue factors when working on a VDU. In Designing for Everyone, edited by Y Queinnec and F Daniellou. London: Taylor & Francis.

Bradley, G. 1983. Effects of computerization on work environment and health: From a perspective of equality between sexes. Occup Health Nursing :35-39.

—. 1989. Computers and the Psychological Environment. London: Taylor & Francis.
Bramwell, RS and MJ Davidson. 1994. Visual display units and pregnancy outcome: A prospective study. J Psychosom Obstet Gynecol 14(3):197-210.

Brandt, LPA and CV Nielsen. 1990. Congenital malformations among children of women working with video display terminals. Scand J Work Environ Health 16:329-333.

—. 1992. Fecundity and the use of video display terminals. Scand J Work Environ Health 18:298-301.

Breslow, L and P Buell. 1960. Mortality and coronary heart disease and physical activity on work in California. J Chron Dis 11:615-626.

Broadbeck, FC, D Zapf, J Prumper, and M Frese. 1993. Error handling in office work with computers: A field study. J Occup Organ Psychol 66:303-317.

Brown, CML. 1988. Human-Computer Interface Guidelines. Norwood, NJ: Ablex.

Bryant, HE and EJ Love. 1989. Video display terminal use and spontaneous abortion risk. Int J Epidemiol 18:132-138.

Çakir, A. 1981. Belastung und Beanspruching bei Biuldschirmtätigkeiten. In Schriften zur Arbeitspychologie, edited by M Frese. Bern: Huber.

Çakir, A, D Hart, and TFM Stewart. 1979. The VDT Manual. Darmstadt: Inca-Fiej Research Association.

Carayon, P. 1993a. Job design and job stress in office workers. Ergonomics 36:463-477.

—. 1993b. Effect of electronic performance monitoring on job design and worker stress: A review of the literature and conceptual model. Hum Factors 35(3):385-396.

Carayon-Sainfort, P. 1992. The use of computers in offices: Impact on task characteristics and worker stress. Int J Hum Comput Interact 4:245-261.

Carmichael, AJ and DL Roberts. 1992. Visual display units and facial rashes. Contact Dermat 26:63-64.

Carroll, JM and MB Rosson. 1988. Paradox of the active user. In Interfacing Thought. Cognitive Aspects of Human-Computer Interaction, edited by JM Carroll. Cambridge: Bradford.

Cohen, ML, JF Arroyo, GD Champion, and CD Browne. 1992. In search of the pathogenesis of refractory cervicobrachial pain syndrome. A deconstruction of the RSI phenomenon. Med J Austral 156:432-436.

Cohen, S and N Weinstein. 1981. Nonauditory effects of noise on behavior and health. J Soc Issues 37:36-70.

Cooper, CL and J Marshall. 1976. Occupational sources of stress: A review of the literature relating to coronary heart disease and mental ill health. J Occup Psychol 49:11-28.

Dainoff, MG. 1982. Occupational Stress Factors in VDT Operation: A Review of Empirical Research in Behavior and Information Technology. London: Taylor & Francis.

Desmarais, MC, L Giroux, and L Larochelle. 1993. An advice-giving interface based on plan-recognition and user-knowledge assessment. Int J Man Mach Stud 39:901-924.

Dorard, G. 1988. Place et validité des tests ophthalmologiques dans l’étude de la fatigue visuelle engendrée par le travail sur écran. Grenoble: Faculté de médecine, Univ. de Grenoble.

Egan, DE. 1988. Individual differences in human-computer interaction. In Handbook of Human-Computer Interaction, edited by M Helander. Amsterdam: Elsevier.

Ellinger, S, W Karmaus, H Kaupen-Haas, KH Schäfer, G Schienstock, and E Sonn. 1982. 1982 Arbeitsbedingungen, gesundheitsverhalten und rheumatische Erkrankungen. Hamburg: Medizinische Soziologie, Univ. Hamburg.

Ericson, A and B Källén. 1986. An epidemiological study of work with video screens and pregnancy outcome: II. A case-control study. Am J Ind Med 9:459-475.

Frank, AL. 1983. Effects of Health Following Occupational Exposure to Video Display Terminals. Lexington, Ky: Department of Preventive Medicine and Environmental Health.

Frese, M. 1987. Human-computer interaction in the office. In International Review of Industrial and Organizational Psychology, edited by CL Cooper. New York: Wiley.

Frölén, H and N-M Svedenstål. 1993. Effects of pulsed magnetic fields on the developing mouse embryo. Biolelectromagnetics 14:197-204.

Fry, HJH. 1992. Overuse syndrome and the Overuse concept. Discussion Papers On the Pathology of Work-Related Neck and Upper Limb Disorders and the Implications for Treatment, edited by G Bammer. Working paper No. 32. Canberra: NCEPH, Australian National Univ.

Gaines, BR and MLG Shaw. 1986. From timesharing to the sixth generation: The development of human-computer interaction. Part I. Int J Man Mach Stud 24:1-27.

Gardell, B. 1971. Alienation and mental health in the modern industrial environment. In Society, Stress, and Disease, edited by L Levi. Oxford: OUP.

Goldhaber, MK, MR Polen, and RA Hiatt. 1988. The risk of miscarriage and birth defects among women who use visual display terminals during pregnancy. Am J Ind Med 13:695-706.

Gould, JD. 1988. How to design usable systems. In Handbook of Human Computer Interaction, edited by M Helander. Amsterdam: Elsevier.

Gould, JD and C Lewis. 1983. Designing for usability—Key principles and what designers think. In Proceedings of the 1983 CHI Conference On Human Factors in Computing Systems, 12 December, Boston. New York: ACM.

Grandjean, E. 1987. Ergonomics in Computerized Offices. London: Taylor & Francis.

Hackman, JR and GR Oldham. 1976. Motivation through the design of work: Test of a theory. Organ Behav Hum Perform 16:250-279.

Hagberg, M, Å Kilbom, P Buckle, L Fine, T Itani, T Laubli, H Riihimaki, B Silverstein, G Sjogaard, S Snook, and E Viikari-Juntura. 1993. Strategies for prevention of work-related musculo-skeletal disorders. Appl Ergon 24:64-67.

Halasz, F and TP Moran. 1982. Analogy considered harmful. In Proceedings of the Conference On Human Factors in Computing Systems. Gaithersburg, Md.: ACM Press.

Hartson, HR and EC Smith. 1991. Rapid prototyping in human-computer interface development. Interact Comput 3(1):51-91.

Hedge, A, WA Erickson, and G Rubin. 1992. Effects of personal and occupational factors on sick building syndrome reports in air-conditioned offices. In Stress and Well-Being At Work-Assessments and Interventions for Occcupational Mental Health, edited by JC Quick, LR Murphy, and JJ Hurrell Jr. Washington, DC: American Psychological Association.

Helme, RD, SA LeVasseur, and SJ Gibson. 1992. RSI revisited: Evidence for psychological and physiological differences from an age, sex and occupation matched control group. Aust NZ J Med 22:23-29.

Herzberg, F. 1974. The wise old Turk. Harvard Bus Rev (Sept./Oct.):70-80.

House, J. 1981. Work Stress and Social Support. Reading, Mass.: Addison-Wesley.

Hutchins, EL. 1989. Metaphors for interactive systems. In The Structure of Multimodal Dialogue, edited by DG Bouwhuis, MM Taylor, and F Néel. Amsterdam: North Holland.

Huuskonen, H, J Juutilainen, and H Komulainen. 1993. Effects of low-frequency magnetic fields on fetal development in rats. Biolelectromagnetics 14(3):205-213.

Infante-Rivard, C, M David, R Gauthier, and GE Rivard. 1993. Pregnancy loss and work schedule during pregnancy. Epidemiology 4:73-75.

Institut de recherche en santé et en sécurité du travail (IRSST). 1984. Rapport du groupe de travail sur les terminaux è écran de visualisation. Montréal: IRSST.

International Business Machines Corp. (IBM). 1991a. Systems Application Architecture. Common User Access Guide-Advanced Interface Design Reference. White Plains, NY.: IBM.

—. 1991b. Systems Application Architecture. Common User Access Guide to User Interface Design. White Plains, NY.: IBM.

International Labour Organization (ILO). 1984. Automation, Work Organisation and Occupational Stress. Geneva: ILO.

—. 1986. Special issue on visual display units. Cond Work Dig .

—. 1989. Working with Visual Display Units. Occupational Safety and Health Series, No. 61. Geneva: ILO.

—. 1991. Worker’s privacy. Part I: Protection of personal data. Cond Work Dig 10:2.

International Organization for Standardization (ISO). 1992. Ergonomic Requirements for Office Work With Visual Display Terminals (VDTs). ISO Standard 9241.Geneva: ISO.

Johansson, G and G Aronsson. 1984. Stress reactions in computerized administrative work. J Occup Behav 5:159-181.

Juliussen, E and K Petska-Juliussen. 1994. The Seventh Annual Computer Industry 1994-1995 Almanac. Dallas: Computer Industry Almanac.

Kalimo, R and A Leppanen. 1985. Feedback from video display terminals, performance control and stress in text preparation in the printing industry. J Occup Psychol 58:27-38.

Kanawaty, G. 1979. Introduction to Work Study. Geneva: ILO.

Karasek, RA, D Baker, F Marxer, A Ahlbom, and R Theorell. 1981. Job decision latitude, job demands, and cardiovascular disease. In Machine-Pacing and Occupational Stress, edited by G Salvendy and MJ Smith. London: Taylor & Francis.

Karat, J. 1988. Software evaluation methodologies. In Handbook of Human-Computer Interaction, edited by M Helander. Amsterdam: Elsevier.

Kasl, SV. 1978. Epidemiological contributions to the study of work stress. In Stress At Work, edited by CL Cooper and R Payne. New York: Wiley.

Koh, D, CL Goh, J Jeyaratnam, WC Kee, and CN Ong. 1991. Dermatologic complaints among visual display unit operators and office workers. Am J Contact Dermatol 2:136-137.

Kurppa, K, PC Holmberg, K Rantala, T Nurminen, L Saxén, and S Hernberg. 1986. Birth defects, course of pregnancy, and work with video display units. A Finnish case-referent study. In Work With Display Units 86: Selected Papers from the International Scientific Conference On Work With Display Units, May 1986, Stockholm, edited by B Knave and PG Widebäck. Amsterdam: North Holland.

Läubli, T, H Nibel, C Thomas, U Schwanninger, and H Krueger. 1989. Merits of periodic visual screening tests in VDU operators. In Work With Computers, edited by MJ Smith and G Salvendy. Amsterdam: Elsevier Science.

Levi, L. 1972. Stress and Distress in Response to Psychosocial Stimuli. New York: Pergamon Press.

Lewis, C and DA Norman. 1986. Designing for error. In User Centered System: New Perspectives On Human-Computer Interation, edited by DA Norman and SW Draper. Hillsdale, NJ.: Erlbaum Associates.

Lidén, C. 1990. Contact allergy: A cause of facial dermatitis among visual display unit operators. Am J Contact Dermatol 1:171-176.

Lidén, C and JE Wahlberg. 1985. Work with video display terminals among office employees. Scand J Work Environ Health 11:489-493.

Lindbohm, M-L, M Hietanen, P Kygornen, M Sallmen, P von Nandelstadh, H Taskinen, M Pekkarinen, M Ylikoski, and K Hemminki. 1992. Magnetic fields of video display terminals and spontaneous abortion. Am J Epidemiol 136:1041-1051.

Lindström, K. 1991. Well-being and computer-mediated work of various occupational groups in banking and insurance. Int J Hum Comput Interact 3:339-361.

Mantei, MM and TJ Teorey. 1989. Incorporating behavioral techniques into the systems development life cycle. MIS Q September:257-274.

Marshall, C, C Nelson, and MM Gardiner. 1987. Design guidelines. In Applying Cognitive Psychology to User-Interface Design, edited by MM Gardiner and B Christie. Chichester, UK: Wiley.

Mayhew, DJ. 1992. Principles and Guidelines in Software User Interface Design. Englewood Cliffs, NJ.: Prentice Hall.

McDonald, AD, JC McDonald, B Armstrong, N Cherry, AD Nolin, and D Robert. 1988. Work with visual display units in pregnancy. Brit J Ind Med 45:509-515.

McGivern, RF and RZ Sokol. 1990. Prenatal exposure to a low-frequency electromagnetic field demasculinizes adult scent marking behavior and increases accessory sex organ weights in rats. Teratology 41:1-8.

Meyer, J-J and A Bousquet. 1990. Discomfort and disability glare in VDT operators. In Work With Display Units 89, edited by L Berlinguet and D Berthelette. Amsterdam: Elsevier Science.

Microsoft Corp. 1992. The Windows Interface: An Application Design Guide. Redmond, Wash.: Microsoft Corp.

Monk, TH and DI Tepas. 1985. Shift work. In Job Stress and Blue Collar Work, edited by CL Cooper and MJ Smith. New York: Wiley.

Moran, TP. 1981. The command language grammar: A representation for the user interface of interaction computer systems. Int J Man Mach Stud 15:3-50.

—-. 1983. Getting into a system: External-internal task mapping analysis. In Proceedings of the 1983 CHI Conference On Human Factors in Computing Systems, 12-15 December, Boston. New York: ACM.

Moshowitz, A. 1986. Social dimensions of office automation. Adv Comput 25:335-404.

Murray, WE, CE Moss, WH Parr, C Cox, MJ Smith, BFG Cohen, LW Stammerjohn, and A Happ. 1981. Potential Health Hazards of Video Display Terminals. NIOSH Research Report 81-129. Cincinnati, Ohio: National Institute for Occupational Safety and Health (NIOSH).

Nielsen, CV and LPA Brandt. 1990. Spontaneous abortion among women using video display terminals. Scand J Work Environ Health 16:323-328.

—-. 1992. Fetal growth, preterm birth and infant mortality in relation to work with video display terminals during pregnancy. Scand J Work Environ Health 18:346-350.

Nielsen, J. 1992. The usability engineering life cycle. Computer (Mar.):12-22.

—-. 1993. Iterative user-interface design. Computer (Nov.):32-41.

Nielsen, J and RL Mack. 1994. Usability Inspection Methods. New York: Wiley.

Numéro spécial sur les laboratoires d’utilisabilité. 1994. Behav Inf Technol.

Nurminen, T and K Kurppa. 1988. Office employment, work with video display terminals, and course of pregnancy. Reference mothers’ experience from a Finnish case-referent study of birth defects. Scand J Work Environ Health 14:293-298.

Office of Technology Assessment (OTA). 1987. The Electronic Supervisor: New Technology, New Tensions. Washington, DC: US Government Printing Office.

Open Software Foundation. 1990. OSF/Motif Style Guide. Englewood Cliffs, NJ: Prentice Hall.

Ostberg, O and C Nilsson. 1985. Emerging technology and stress. In Job Stress and Blue Collar Work, edited by CL Cooper and MJ Smith. New York: Wiley.

Piotrkowski, CS, BFG Cohen, and KE Coray. 1992. Working conditions and well-being among women office workers. Int J Hum Comput Interact 4:263-282.

Pot, F, P Padmos, and A Brouwers. 1987. Determinants of the VDU operator’s well-being. In Work With Display Units 86. Selected Papers from the International Scientific Conference On Work With Display Units, May 1986, Stockholm, edited by B Knave and PG Widebäck. Amsterdam: North Holland.

Preece, J, Y Rogers, H Sharp, D Benyon, S Holland, and T Carey. 1994. Human Computer Interaction. Reading, Mass.: Addison-Wesley.

Quinter, J and R Elvey. 1990. The neurogenic hypothesis of RSI. Discussion Papers On the Pathology of Work-Related Neck and Upper Limb Disorders and the Implications for Treatment, edited by G Bammer. Working paper No. 24. Canberra: NCEPH, Australian National Univ.

Rasmussen, J. 1986. Information Processing and Man-Machine Interaction. An Approach to Cognitive Engineering. New York: North Holland.

Ravden, SJ and GI Johnson. 1989. Evaluating Usability of Human-Computer Interfaces: A Practical Approach. West Sussex, UK: E Horwood.

—. 1992. Systems Application Architecture: Common Communications Support. Englewood Cliffs, NJ: Prentice Hall.

Reed, AV. 1982. Error correcting strategies and human interaction with computer systems. In Proceedings of the Conference On Human Factors in Computing Systems Gaithersburg, Md.: ACM.

Rey, P and A Bousquet. 1989. Visual strain of VDT operators: The right and the wrong. In Work With Computers, edited by G Salvendy and MJ Smith. Amsterdam: Elsevier Science.

—. 1990. Medical eye examination strategies for VDT operators. In Work With Display Units 89, edited by L Berlinguet and D Berthelette. Amsterdam: Elsevier Science.

Rheingold, HR. 1991. Virtual Reality. New York: Touchstone.

Rich, E. 1983. Users are individuals: Individualizing user models. Int J Man Mach Stud 18:199-214.

Rivas, L and C Rius. 1985. Effects of chronic exposure to weak electromagnetic fields in mice. IRCS Med Sci 13:661-662.

Robert, J-M. 1989. Learning a computer system by unassisted exploration. An example: The Macintosh. In MACINTER II Man-Computer Interaction Research, edited by F Klix, N Streitz, Y Warren, and H Wandke. Amsterdam: Elsevier.

Robert, J-M and J-Y Fiset. 1992. Conception et évaluation ergonomiques d’une interface pour un logiciel d’aide au diagnostic: Une étude de cas. ICO printemps-été:1-7.

Roman, E, V Beral, M Pelerin, and C Hermon. 1992. Spontaneous abortion and work with visual display units. Brit J Ind Med 49:507-512.

Rubino, GF. 1990. Epidemiologic survey of ocular disorders: The Italian multicentric research. In Work With Display Units 89, edited by L Berlinguet and D Berthelette. Amsterdam: Elsevier Science.

Rumelhart, DE and DA Norman. 1983. Analogical processes in learning. In Cognitive Skills and Their Acquisition, edited by JR Anderson. Hillsdale, NJ: Lawrence Erlbaum.

Ryan, GA and M Bampton. 1988. Comparison of data process operators with and without upper limb symptoms. Community Health Stud 12:63-68.

Ryan, GA, JH Mullerworth, and J Pimble. 1984. The prevalence of repetition strain injury in data process operators. In Proceedings of the 21st Annual Conference of the Ergonomics Society of Australia and New Zealand. Sydney.

Sainfort, PC. 1990. Job design predictors of stress in automated offices. Behav Inf Technol 9:3-16.

—-. 1991. Stress, job control and other job elements: A study of office workers. Int J Ind Erg 7:11-23.

Salvendy, G. 1992. Handbook of Industrial Engineering. New York: Wiley.

Salzinger, K and S Freimark. 1990. Altered operant behavior of adult rats after perinatal exposure to a 60-Hz electromagnetic field. Biolelectromagnetics 11:105-116.

Sauter, SL, CL Cooper, and JJ Hurrell. 1989. Job Control and Worker Health. New York: Wiley.

Sauter, SL, MS Gottlieb, KC Jones, NV Dodson, and KM Rohrer. 1983a. Job and health implications of VDT use: Initial results of the Wisconsin-NIOSH study. Commun ACM 26:284-294.

Sauter, SL, MS Gottlieb, KM Rohrer, and NV Dodson. 1983b. The Well-Being of Video Display Terminal Users. An Exploratory Study. Cincinnati, Ohio: NIOSH.

Scapin, DL. 1986. Guide ergonomique de conception des interfaces homme-machine. Rapport de recherche no. 77. Le Chesnay, France: INRIA.

Schnorr, TM, BA Grajewski, RW Hornung, MJ Thun, GM Egeland, WE Murray, DL Conover, and WE Halperin. 1991. Video display terminals and the risk of spontaneous abortion. New Engl J Med 324:727-733.

Shepherd, A. 1989. Analysis and training in information technology tasks. In Task Analysis for Human-Computer Interaction, edited by D Diaper. Chichester: E Horwood.

Shneiderman, B. 1987. Designing the User Interface: Strategies for Effective Human-Computer Interaction. Reading, Mass.: Addison-Wesley.

Sjödren, S and A Elfstrom. 1990. Eye discomfort among 4000 VDU users. In Work With Display
Units 89, edited by L Berlinguet and D Berthelette. Amsterdam: Elsevier Science.

Smith, MJ. 1987. Occupational stress. In Handbook of Ergonomics/Human Factors, edited by G Salvendy. New York: Wiley.

Smith, MJ and BC Amick. 1989. Electronic monitoring at the workplace: Implications for employee control and job stress. In Job Control and Worker Health, edited by S Sauter, J Hurrel, and C Cooper. New York: Wiley.

Smith, MJ, P Carayon, and K Miezio. 1987. VDT technology: Psychosocial and stress concerns. In Work With Display Units, edited by B Knave and PG Widebäck. Amsterdam: Elsevier Science.

Smith, MJ and P Carayon-Sainfort. 1989. A balance theory of job design for stress reduction. Int J Ind Erg 4:67-79.

Smith, MJ, BFG Cohen, LW Stammerjohn, and A Happ. 1981. An investigation of health complaints and job stress in video display operations. Hum Factors 23:387-400.

Smith, MJ, P Carayon, KH Sanders, S-Y Lim, and D LeGrande. 1992a. Electronic performance monitoring, job design and worker stress. Appl Ergon 23:17-27.

Smith, MJ, G Salvendy, P Carayon-Sainfort, and R Eberts. 1992b. Human-computer interaction. In Handbook of Industrial Engineering, edited by G Salvendy. New York: Wiley.

Smith, SL and SL Mosier. 1986. Guidelines for Designing User Interface Software. Report ESD-TR-278. Bedford, Mass.: MITRE.

South Australian Health Commission Epidemiology Branch. 1984. Repetition Strain Symptoms and Working Conditions Among Keyboard Workers Engaged in Data Entry or Word Processing in the South Australian Public Service. Adelaide: South Australian Health Commission.

Stammerjohn, LW, MJ Smith, and BFG Cohen. 1981. Evaluation of work station design factors in VDT operations. Hum Factors 23:401-412.

Stellman, JM, S Klitzman, GC Gordon, and BR Snow. 1985. Air quality and ergonomics in the office: Survey results and methodologic issues. Am Ind Hyg Assoc J 46:286-293.

—-. 1987a. Comparison of well-being among non-machine interactive clerical workers and full-time and part-time VDT users and typists. In Work With Display Units 86. Selected Papers from the International Scientific Conference On Work With Display Units, May 1986, Stockholm, edited by B Knave and PG Widebäck. Amsterdam: North Holland.

—-. 1987b. Work environment and the well-being of clerical and VDT workers. J Occup Behav 8:95-114.

Strassman, PA. 1985. Information Payoff: The Transformation of Work in the Electronic Age. New York: Free Press.

Stuchly, M, AJ Ruddick, et al. 1988. Teratological assessment of exposure to time-varying magnetic fields. Teratology 38:461-466.

Sun Microsystems Inc. 1990. Open Look. Graphical User Interface Application Style Guidelines. Reading, Mass.: Addison-Wesley.

Swanbeck, G and T Bleeker. 1989. Skin problems from visual display units: Provocation of skin symptoms under experimental conditions. Acta Derm-Venereol 69:46-51.

Taylor, FW. 1911. The Principles of Scientific Management. New York: Norton & Co.

Thimbleby, H. 1990. User Interface Design. Chichester: ACM.

Tikkanen, J and OP Heinonen. 1991. Maternal exposure to chemical and physical factors during pregnancy and cardiovascular malformations in the offspring. Teratology 43:591-600.

Tribukait, B and E Cekan. 1987. Effects of pulsed magnetic fields on embryonic development in mice. In Work With Display Units 86: Selected Papers from the International Scientific Conference On Work With Display Units, May 1986, Stockholm, edited by B Knave and PG Widebäck. Amsterdam: North Holland.

Wahlberg, JE and C Lidén. 1988. Is the skin affected by work at visual display terminals? Dermatol Clin 6:81-85.

Waterworth, JA and MH Chignell. 1989. A manifesto for hypermedia usability research. Hypermedia 1:205-234.

Westerholm, P and A Ericson. 1986. Pregnancy outcome and VDU work in a cohort of insurance clerks. In Work With Display Units 86. Selected Papers from the International Scientific Conference On Work With Display Units, May 1986, Stockholm, edited by B Knave and PG Widebäck. Amsterdam: North Holland.

Westlander, G. 1989. Use and non-use of VDTs—Organization of terminal work. In Work With Computers: Organizational, Management, Stress and Health Aspects, edited by MJ Smith and G Salvendy. Amsterdam: Elsevier Science.

Westlander, G and E Aberg. 1992. Variety in VDT work: An issue for assessment in work environment research. Int J Hum Comput Interact 4:283-302.

Wickens, C. 1992. Engineering Psychology and Human Performance. New York: Harper Collins.

Wiley, MJ and P Corey. 1992. The effects of continuous exposure to 20-khz sawtooth magnetic fields on the litters of CD-1 mice. Teratology 46:391-398.

Wilson, J and D Rosenberg. 1988. Rapid prototyping for user interface design. In Handbook of Human-Computer Interaction, edited by M Helander. Amsterdam: Elsevier.

Windham, GC, L Fenster, SH Swan, and RR Neutra. 1990. Use of video display terminals during pregnancy and the risk of spontaneous abortion, low birthweight, or intrauterine growth retardation. Am J Ind Med 18:675-688.

World Health Organization (WHO). 1987. Visual Display Terminals and Workers’ Health. Geneva: WHO.

—-. 1989. Work with visual display terminals: Psychosocial aspects and health. J Occup Med 31:957-968.

Yang, C-L and P Carayon. 1993. Effects of job demands and job support on worker stress: A study of VDT users. Behav Inf Technol .

Young, JE. 1993. Global Network. Computers in a Sustainable Society. Washington, DC: Worldwatch Paper 115.

Young, RM. 1981. The machine inside the machine: Users’ models of pocket calculators. Int J Man Mach Stud 15:51-85.

Zecca, L, P Ferrario, and G Dal Conte. 1985. Toxicological and teratological studies in rats after exposure to pulsed magnetic fields. Bioelectrochem Bioenerget 14:63-69.

Zuboff, S. 1988. In the Age of the Smart Machine: The Future of Work and Power. New York: Basic Books.