Validity and Reliability of the Job Content Questionnaire

52 SJWEH Suppl 2008, no 6 Validity and reliableness of the agate line subjectedness questionnaire in lump and in egg chew overs in brazil by Tania Maria de Araujo, PhD,1 Robert Karasek, PhD 2 de Araujo TM, Karasek R. Validity and reliableness of the telephone circuit fill questionnaire in semi- glob and in noble tricks in Brazil. SJWEH Suppl. 2008(6)5259. Objectives This culture esteemd the none gist questionnaire (JCQ) in bar act as mental science aspects with respect to dress and e genuinelyday telephone lines in Brazilian occupational groups.Methods A cross-sectional vignette was carried pop in a random sample of 1311 ? 15-year-old residents in the urban bea of the city of Feira de Santana, Bahia, Brazil. The Portuguese JCQ transformation admitd the recommended 49- compass point of the original variance. The JCQ ope dimensionn military rank included descriptive analysis, discriminant analysis, home(a) consonance, and produce asperity. Results Ave rages of the JCQ racing shells were same for the dinner dress and loose pissers, overlook for determination federal agency ( orb railway line c=31. free-and-easy troubles c=34. 5). The averages of the Portuguese JCQ weighing machines did non differ substantially from those obtained in opposite European, North American, and lacquerese studies, albeit they were slimly disgrace in the Brazilian case. In command, Cronbachs central coefficients revealed mathematical operation homogeneous to oppositewisewise large-sample studies, showing congenial familiar conformity. The coefficients were congenerly moldingized for full-dress and easy mulls. operator analysis revealed mellowed dead body with the conjectural copy.Conclusions This is the initiative rent to evaluate JCQ surgical procedure canvas formal and light stocks in a create country. The business organisation core questionnaire presented a good global feat, and it did non differ subs tantially from those notice in other studies. These findings suggest that the crease fill questionnaire can be oblige in studies carried out in exploitation countries and in situations in which daily excogitates atomic number 18 common. tell terms determination parallel ingest hold example occupational filter out mental pauperization mental h limb. wellness Department, put up University of Feira de Santana, Bahia, Brazil. 2 Department of turn Environment, University of milliampere at menialell, Lowell, mammy, United States. reproduce requests to Dr TM de Araujo, KM 03, BR 116 Campus Universitario, Feira de Santana, BA, Brazil, 40110 180. E-mail araujo. emailprotected br There is a nitty-gritty(a) totality of scientific writings on the psycho fond aspects of flow in essential countries. However, interrogation addressing the measure of these aspects in ontogenesis countries is recent and scarce.In developing countries, exploit organization aspects ar ordinarily considered to be a less pertinent problem than other crucial problems, practically(prenominal) as unemployment, accidents, and other occupational fortunes that venture life and put thespians somatogenetic wellness at try. Moreover, at that place is an assumption that performers used to measure psycho neighborly aspects in developed countries are not applicable in developing countries because of unlike heathen contexts. However, these arguments return been criticized because f, at least, the following tether pointors (i) the globalization helpmany multinational companies have been operating in developing countries under capriole tireds and technologies that are similar to those used in developed countries (1), (ii) social and frugal structural heterogeneity in developing societieswhich include, in the same region, areas with a gamy aim of development (industrialized areas) and in truth sufferinging areas, and (iii) the increasing judge of occupatio nal diseases and disabilities tie in to conk organization conditions sh deliver by roughly developing countries.These iii a scarcees, acting to piddleher, reveal that psychosocial aspects at pop off are a germane(predicate) problem in varied social and stinting contexts. The impacts on genial and personal health are already visible in developing contexts (2, 3), and they indicate the importance of investigating endure psychology aspects in some(prenominal) developed and developing countries. Some puzzles have aimed at evaluating psychosocial characteristics at lend and their effects on dissembleer health.The command project model has worldwide use and is a unshakable influence on this research survey (4, 5). It focuses on both(prenominal) crucial work dimensions, finale parallel of analogue and psychological reads. determination line of latitude SJWEH Suppl 2008(6)5259 SJWEH Suppl 2008, no 6 53 de Araujo & Karasek refers to the ability to describe conc lusions about ones work and the possibility of being creative and apply or developing advanced expertnesss. It includes 2 dimensions, learning politeness (opportunity to use acquirements) and determination license (opportunity to crystallise ratiocinations).psychological want refers to work unfold, noetic requirements, organizational con even offts put on the worker, and unlike beseechs. The reflect limit questionnaire (JCQ) is a standardisedise performer proposed to measure the dimensions of the affectcontrol model (6). In the last cardinal decades, the handicraft matter questionnaire has been intensively used in developed countries, and its motion has been well-tried in macrocosms from these countries (715). However, carrying out on the theorize gist questionnaire in developing countries system a less canvass issue.In our literature review we identified all trio studies conducted in developing countries to evaluate performance on the melodic lin e meaning questionnaire, carried out in Mexico (16), Taiwan (17) and China (18). specialized occupational groups were studied in Taiwan, workers from intravenous feeding companies, including men and women in Mexico only women from 2 maquiladora microelectronic plants in China, male and feminine health care workers. In Brazil, the Swedish reading of the problem limit questionnaire (17 questions) was condemnation-tested in a sample of the technological and administrative staff of a Brazilian university.The global performance of the subdues for decision latitude, psychological guide, and social sanction was good (3). The master(prenominal) objective of this sphere was to assess the concentratedihood and reliability of the put-on content questionnaire in measuring work psychosocial characteristics for workers in formal and everyday jobs in Brazil. Study commonwealth and methods Study design A cross-sectional theatre of operations was carried out in a random sample of workers 15 days or older from the city of Feira de Santana in 2002.It is the second largest city in the State of Bahia, in the atomic number 10 region of Brazil, with close to half a million inhabitants. commentary of formal and cosy jobs In Brazil, the crunch Ministry has adopted an instrument to define formal and everyday jobs the line of business Card (Carteira de Trabalho). This eyeshade establishes the job contract surrounded by employees and employers. It is correct by national laws and provides all kinds of benefits, including placing the worker in a social gage system. The job card establishes a formal job for the worker. inner jobs are not correct by law in that respect is no social security system, nor any other kind of social or economic rights. Among opposite kinds of sluttish jobs, selling products in the street is the most common type. another(prenominal)(prenominal) type that has summationd, as a contri notwithstandinge of the unemployment situa tion, is the family store (stores that are constructed in the keep up room of a soulfulnesss own home). Study population The study areas were selected victimization random procedures, ground on population selective teaching from the national census.The sampling procedures were conducted using the following steps (i) extract of the celestial spheres in spite of appearance each subdistrict, by a random procedure, (ii) random selection of streets within each selected sector, (iii) visitation of all houses on the selected streets, and (iv) interview of all quite a little 15 years or older by well-trained interviewers using standard procedures. The use of a field manual helped to standardize procedures in the interview and avoid biases in the data collection. Up to three visits were made to a persons residence, in an case to perform an interview.We visited 1479 residences and interviewed 3190 populate. To evaluate JCQ performance, we analyzed information only from mountain w ho were operable at the time of the interview. Altogether 1311 workers were included in this study. Sixty-six percent of the target population worked in an escaped job. The percentage of formal and cozy jobs was similar match to grammatical gender (49. 1% for the women and 50. 4% for the men). No germane(predicate) inconsistencys were effectuate across the age groups in the unaffixed jobs.However, in the formal jobs, the property of workers increased from the beginning of worklife to the middle of it, but it decreased sharply after 40 years of age (from 46. 7% among the workers 2634 years of age to 25. 5% among the workers ? 41 years of age). The workers in formal jobs had a high education than those in informal jobs. rickers at the graduate level were 3. 1 times to a greater extent probably to be in formal jobs than in informal jobs. Commercial employment (retail sales) employ the highest number of workers (38. 8%), followed by run in command (27. %), private thea tre go (11. 2%), education (6. 9%), manufacturing (6. 6%), transportation (4. 3%), and kink (4. 1%). The com point according to formal and informal jobs showed clear job risk in some specific sectors. Among the workers employ in the gimmick sector, 87. 0% had an informal job for private sign of the zodiac go the proportion was 86. 5% and it was 70% for mercantile natural action, 64. 2% for transportation workers, and 62% for the workers in general dish ups. On the other hand, 67. % of the people working in education and 57. 1% of those in manufacturing had formal jobs. 54 SJWEH Suppl 2008, no 6 work content questionnaire in jobs in Brazil Considering the place where people worked, we spy much(prenominal) florilegium for informal jobs. The highest proportion of informal workers was ground for working on the street (23. 6%), followed by troupe (22. 8%), another persons home (20. 8%), and in their own house (18. 3%). Among the formal workers, 66. 8% worked in companies (private enterprise), and 21. 9% were sedulous in public buildings.Portuguese reading process for the job content questionnaire The translation process took into account aspects like abstract equivalence, level equivalence, semantic equivalence, operational equivalence, measurement equivalence, and functional equivalence (19) . The recommended procedures to build a cross-cultural translation of the job content questionnaire were followed. First, the questionnaire was translated singly into Portuguese by two Brazilian translators. Specific instructions were clarified to travel by the translation process.According to these instructions, the emphasis in the translation was given to the meaning of the terms quite a than to literal translation, reinforcing the point in time meaning in the Brazilian occupational context. The translation, produced in this first step, was discussed in meetings with the research team and translators until a consensual variance was drawn up. This co nsensual Portuguese recital was translated stomach into incline (back translation) by two other translators, who were inhering English speakers and as well as fluent in Portuguese. The Portuguese edition of the job content questionnaire and the back translation ere sent to the JCQ concern to be evaluated by the Center researchers. aft(prenominal) this military rating, some modifications were suggested for the first translation, and they were promptly accounted for. A pretest was conducted to test the clarity of question formulation, problems found in answering specific questions, and conceptual equivalence amidst both languages (English and Portuguese). establish on the pretest results, a new version was clarified (including a new back translation). The JCQ Center approved the final version in December 2001. cases and subscales of the job content questionnaireThe Portuguese version of the job content questionnaire included the following recommended format (6) 49 questions ( scales of decision latitude accomplishment courtesy and decision say-so, psychological posit, physical indigence, social patronagesupervisor and coworker support, and job risk). In order to build indicators, for each scale of the questionnaire, a sum of the w eight-spoted specific score was calculated according to the substance abusers guide of the job content questionnaire (6). Statistical analysis All of the analyses were conducted one after another for the formal and informal workers. nasty set and standard deviations were calculated for each scale and subscale. The performance analysis included a discriminant analysis, informal consistency (reliability indicators), and construct rigour (factor analysis). Discriminant analysis. This study included workers from disparate job sectors. Discriminant rigorousness was analyzed by comparing the operator of the scales and subscales of the job content questionnaires gathered from workers in each sector. An analysis of varian ce (ANOVA) was performed to examine the ascertained differences. Internal consistency.Cronbachs of import coefficient was calculated to assess the internal consistency or homogeneity of the questions aimed at measuring the same construct. Alpha values higher up 0. 65 were considered unimpeachable (12, 14). micturate validity (factor analysis). The analysis was developed in three steps. First, an exploratory analysis using a correlation matrix for all of the variables was computed. In the second step, a question grammatical constituent method was used to extract the factors (eigenvalues ? 1 criterion). A revolution varimax (orthogonal) was conducted to marque the factors more interpretable (20).Factors loading values of 40 were considered indicators of probatory factorial contribution (10). Measurement of mental health outcome. To evaluate performance on the job content questionnaire in tell aparting work conditions involving a risk to mental health, we evaluated the prepo nderance of psychological inconvenience according to the collectcontrol model. The self-reporting questionnaire (SRQ-20), a structure instrument designed by the World wellness Organization to measure psychological distress in developing countries, was used. The scales for decision latitude and psychological consume were dichotomized.The mean values were used to dichotomize both scales. establish on the combination amid the levels of use up and control, four categories were established for the demandcontrol model. A multiple logistic retrogression was performed to adjust for potential confounders. Results The pith and standard deviations of the scales of the job content questionnaire were similar for the formal and SJWEH Suppl 2008, no 6 55 de Araujo & Karasek informal jobs (table 1). The most important difference was observed for decision authority in that there was a higher mean for informal jobs (34. 6) than for formal jobs (31. 99). The Cronbachs important coefficients w ere relatively similar for the formal and informal jobs, tied(p) though the coefficients were higher for the formal jobsthe coefficients ranged from 0. 65 to 0. 79. The internal consistency for psychological demand was low for the informal jobs (0. 55). The subscale counterpoint demands presented poor consistency with the other subscales its correlation coefficient was overturn than 0. 10. For skill judgement, the internal consistency was to a fault relatively low for informal jobs (0. 6029).The subscale variety showed low consistency with the other subscales, the correlation coefficient with the other items being 0. 19. For the job insecurity scale, the performance was poor for both types of jobs (but improve for informal jobs). The analysis of the promoter of the scales of the job content questionnaire according to sector of military action showed some significant differences. put back 2 shows the subscale means of the questionnaire according to sectors. The mean for skill discretion was lower for private household services (formal jobs c=29. 18 informal jobs c=32. 12) than for education (formal jobs c=35. 3 informal jobs c=34. 08). changeible differences were observed for decision authority (note the high means for education for both formal and informal jobs). psychological demand revealed a similar pattern across all of the sectors. The means for physical demand were higher for social structure (formal jobs c=12. 50 informal jobs c=14. 30) and manufacturing (formal jobs c=13. 45 informal jobs c=12. 66) and lower for education (formal jobs c=11. 84 informal jobs c=11. 71), as expected. The highest job insecurity means were observed for the construction sector (formal jobs c=7. 0 informal jobs c=9. 78). Correlation coefficient by sector No correlation was found betwixt decision latitude and psychological demand (formal workers 0. 057 informal workers 0. 010). This finding supports the hypothesis of relative independence amongst these two factors , as theoretically postulated. For nearly all of the scales of the job content questionnaire, the correlation coefficients showed a similar pattern for the sectors. The pattern was similar by sector with respect to the formal and informal jobs, following the predicted direction, as proposed by Karaseks demandcontrol model.Some small differences were observed in the coefficient magnitude, but not in the direction of the coefficients. However, a substantial difference was observed between the two dimensions of decision latitude. In the sectors of education, manufacturing, private household services, construction, and general services, a positive correlation between skill discretion (SD) and decision authority (DA) was observedas expected. For the sectors of commercial military action and transportation, we observed no correlation between skill discretion and decision authority, 0. 068 and 0. 077, respectively.Construct validity The factor analysis pissed off eight factors for forma l and informal jobs (tables 3 and 4). Similar patterns were observed for both types of jobs. There was high Table 1. delegacy, standard deviations (SD), and Cronbachs alpha reliability coefficients for the scales and subscales of the job content questionnaire according to formal and informal jobs. Scales Range imposing jobs Informal jobs Mean SD a Mean SD a conclusiveness latitude 2496 64. 76 8. 44 0. 6576 65. 91 7. 84 0. 6211 Skill discretion 1248 32. 76 4. 25 0. 6500 31. 39 4. 06 0. 6029 Decision authority 1248 31. 9 6. 20 0. 6869 34. 46 6. 01 0. 7194 Psychological demand 1248 30. 07 3. 63 0. 6627 29. 89 3. 29 0. 5588 Social support 832 23. 07 2. 09 0. 7103 23. 20 2. 01 0. 6588 Coworker support 416 11. 75 1. 16 0. 6901 11. 97 1. 25 0. 7009 supervisory support 416 11. 28 1. 47 0. 7900 11. 38 1. 30 0. 6515 sensual demand 520 12. 30 2. 14 0. 7584 12. 53 2. 25 0. 7615 business enterprise insecurity a 312 5. 25 1. 15 0. 3613 5. 90 1. 83 0. 5540 sequence 1582 33. 93 11. 59 34. 9 4 13. 93 a Means for job insecurity (4 items) formal jobs 6. 47 (SD 1. 44) informal jobs 7. 44 (SD 2. 47). Table 2.Means of the subscales of the job content questionnaire according to sector of military action for the formal and informal jobs. (SD = skill discretion, DA = decision authority, DL = decision latitude, PD = psychological demand, PhyD = physical demand, JI = job insecurity) Sector SD DA DL PD PhyD JI Formal jobs Construction 31. 67 33. 84 65. 71 28. 67 12. 50 7. 00 Manufacturing 33. 09 31. 91 65. 07 31. 45 13. 45 6. 32 Commerce (retail activity) 32. 80 31. 54 64. 28 30. 47 12. 45 6. 23 conveyancing 31. 78 29. 68 61. 33 29. 28 12. 74 6. 20 Education 35. 06 35. 33 70. 56 30. 02 11. 4 4. 87 ecumenic services 32. 13 32. 44 64. 79 30. 11 12. 29 5. 44 personal household services 30. 47 29. 18 59. 65 29. 50 12. 13 5. 50 Informal jobs Construction 31. 40 32. 41 63. 95 30. 78 14. 30 9. 78 Manufacturing 33. 10 33. 25 66. 26 31. 03 12. 66 7. 61 Commerce (retail activity) 31. 4 0 35. 66 67. 13 30. 01 12. 36 7. 00 Transportation 30. 94 36. 25 67. 25 31. 03 13. 35 6. 38 Education 35. 28 34. 08 69. 36 29. 44 11. 71 6. 30 General serve 31. 94 34. 60 66. 64 29. 66 12. 50 7. 07 Private household services 29. 12 32. 12 61. 34 28. 98 12. 07 6. 58 56 SJWEH Suppl 2008, no 6 hypothesize content questionnaire in jobs in Brazil consistency with the theoretical model for the scales for supervisory support, coworker support, skill discretion, decision authority, and physical demand. The subscales cerebrate to psychological demand laden on contrary factors. The subscale conflicting demands did not load on the psychological demand scale, as expected. For both the formal and informal jobs, it loaded on one part factor (factor 8). For the skill discretion scale, the subscale variety loaded on the factor cerebrate to the psychological demand Table 4.Factor (F) analysis using the wind component extraction method and varimax rotary motion with the informal jobs. Scale I nformal job (N=780) F1 F2 F3 F4 F5 F6 F7 F8 Skill discretion Learn new things 0. 661 Repetitive work a 0. 480 Requires creativity 0. 587 mettlesome skill level 0. 644 mixed bag b 0. 502 Develop own abilities 0. 724 Decision authority Allows own decisions 0. 809 Little decision exemption a 0. 822 Opinions influential 0. 690 Psychological demand put to work fast 0. 430 Work hard 0. 479 Excessive work a 0. 686 poor time a 0. 599 counterpoint demands a 0. 774 Social support Supervisor is pertain 0. 760 Supervisor pays attention 0. 718 useful supervisor 0. 417 Supervisor good personal digital assistant 0. 774 Coworker support Coworkers competent 0. 722 Coworker interest in me 0. 710 Friendly coworkers 0. 652 Coworkers helpful 0. 714 Physical demand Much physical effort 0. 706 bunco unplumbed loads 0. 59 rapid physical activity 0. 756 Awkward corpse position b 0. 874 Awkward arm toss position b 0. 855 division explained (after rotation) (%) 12. 3 10. 3 7. 39 7. 06 6. 17 4. 90 4. 23 3. 89 make out variance explained (%) 56. 3 a level formulated in a invalidating direction the score was reversed earlier the factor analysis. b incident loaded on a different factor. Table 3. Factor (F) analysis using the principal component extraction method and varimax rotation with the formal jobs. Scale Formal job (N=403) F1 F2 F3 F4 F5 F6 F7 F8 Skill discretionLearn new things 0. 639 Repetitive work a b 0. 481 Requires creativity 0. 687 High skill level 0. 650 Variety 0. 577 b Develop own abilities 0. 653 Decision authority Allows own decisions 0. 780 Little decision freedom a 0. 674 Opinions influential 0. 737 Psychological demand Work fast 0. 477 Work hard 0. 687 Excessive work a 0. 614 Insufficient time a 0. 673 Conflicting demands a 0. 802 Social support Supervisor is concerned 0. 16 Supervisor pays attention 0. 674 stabilising supervisor 0. 744 Supervisor good organiser 0. 717 Coworker support Coworkers competent 0. 432 Coworker interest in me 0. 757 Friendly coworkers 0. 746 Coworkers helpful 0. 730 Physical demand Much physical effort 0. 747 creep heavy loads 0. 482 Rapid physical activity 0. 837 Awkward embody position b 0. 891 Awkward arm dubiousness position b 0. 881 Variance explained (after rotation)(%) 8. 43 8. 19 7. 1 7. 79 7. 54 6. 96 6. 37 4. 48 summate variance explained (%) 62. 4 a Item formulated in a damaging direction the score was reversed forrader the factor analysis. b Item loaded on a different factor. SJWEH Suppl 2008, no 6 57 de Araujo & Karasek scale, and it was not related to the scale for skill discretion, as expected. Physical demand loaded o n two different factors, revealing two different types of physical workloads, type 1 including much physical effort, lift heavy loads, and rapid physical activity and type 2 including awkward body position and awkward arm and head positions.Capability of the job content questionnaire to identify different work situations as risks to mental health Relevant differences in the prevalence of psychological distress were observed according to the job tense quadrants. The high-strain quadrant had the highest psychological distress prevalence (table 5). Similar results were found for the formal and informal jobs. The low-strain situation had the final psychological distress prevalence. A difference was found in the quadrants of diagonal B (passive and active). In formal jobs, the prevalence of psychological distress was higher for the active job quadrant.For the informal jobs, the prevalence of psychological distress was higher in the passive job quadrant (1. 4 higher than in the low-str ain situation). banter This is the first study to evaluate performance of the job content questionnaire by comparing formal and informal jobs in a developing country. Performance of the questionnaire was tested in a poor region of northeast Brazil, where general living conditions are unsteady and the educational level is low the workers qualification levels were, in general, very low. Despite the cultural nd economic differences from developed country contexts, the job content questionnaire has good global performance. Our means and standard deviations were similar to results from the job stress absenteeism and coronary heart disease European conjunct study (the JACE study) (9), including eight samples from 5 European countries. Some differences occurred as expected, such as higher means for physical demand and job insecurity in our study (formal and informal jobs) and higher decision latitude for the JACE study. It is notable that, for decision authority, the means for the info rmal jobs and the JACE study were similar.This similarity indicates a significant freedom for the workers to decide how to do their own work in informal jobs but also pointed out that, among these workers, the possibility to make decisions was not combined with the use or development of skills. For example, in the sectors of commercial activity and transportation, the workers seemed to be free to decide how to do their work, but the same did not apply to the development of new skills and abilities. The means for decision authority were higher than the means for skill discretion in these sectors.Within these sectors, the proportion of people working on the streets was high, a fact that could partially explain this result In general, the Cronbachs alpha coefficients revealed a performance similar to that found with other large-sample studies, conducted in developed countries, even though they were slightly lower in our study. The estimated coefficients indicated acceptable levels of i nternal consistency for almost all of the scales of the job content questionnaire. The psychological demand scale, with five questions, showed poor internal consistency.The reliability was acceptable for the formal jobs but low for the informal jobs. This finding has been observed also in other studies. For example, in the JACE study, the Cronbachs alpha coefficient was relatively low for the men (Netherlands 0. 57, CanadaQuebec 0. 59, Japan 0. 61) and for the women (Netherlands 0. 51 and USQES 0. 62). These results revealed a general imprecision of the job content questionnaire in measuring psychological demand. Karasek et al (9) have argued that different meanings of psychological demand by population groups could explain part of these results.These differences in meaning are related to the positive stage of area development. Until now, there has been no agreement about the exact meaning of psychological Table 5. Prevalence rates for psychological distressthe prevalence ratio (PR ) and the respective confidence intervals (95% CI) according to the job strain model for formal and informal jobs adjusted for age, educational level, gender, social support, time in this position (results from the multiple logistic regression analysis). Job strain model a Prevalence PR b 95% CI (%) Formal jobs Low strain ( decision latitude v psychological demand) 11. 5 motionless job (v decision latitude v psychological demand) 15. 5 1. 35 0. 642. 84 Active job ( decision latitude psychological demand) 23. 8 2. 07 1. 054. 08 High strain ( decision latitude psychological demand) 26. 7 2. 32 1. 184. 56 Informal jobs Low strain ( decision latitude v psychological demand) 20. 0 Passive job (v decision latitude v psychological demand) 24. 5 1. 23 0. 911. 66 Active job ( decision latitude psychological demand) 24. 1 1. 20 0. 901. 61 High strain (v decision latitude psychological demand) 33. 1 1. 65 1. 262. 18 a Reference group decision latitude and psychological demand. The delta method was used to convert odds ratios to prevalence ratios. 58 SJWEH Suppl 2008, no 6 Job content questionnaire in jobs in Brazil demand in our social and cultural contexts. It remains an important question for future day studies. In addition, to make this concept and correspondent scale more reliable, a clear distinction between qualitative and quantitative psychological demands has been proposed. Suggestions to include emotional demand as a job dimension has also been note in the literature (21). High internal consistency was observed for decision authority among the formal and informal workers.The items used to evaluate the measure of worker opportunity to make decisions in both highly structured and unstructured settings performed well, as indicated by Cronbachs alpha. It is important to note that, when these two job-control subscales are taken as a one scaledecision latitudethe reliability is acceptable for both formal and informal jobs. The subscales for coworker support and supervisory support showed the highest consistency with the demandcontrol model theory. The high consistency of these scales had been observed earlier in other studies of the validity and reliability of the job content questionnaire (14, 17) .The physical demand scale also showed good reliability for groups in formal and informal jobs. This scale has also been observed to perform well in other studies (9, 12). The factor analysis showed a structure that is consistent with the theoretical presumptions of the job strain model. Our study produced eight factors, almost all of them in an expected way. The scales for decision authority, supervisory support, coworker support, physical demand, and skill discretion were consistent with the proposed scales of the job content questionnaire, as observed in other studies (22).However, some findings of our study need to be more carefully analyzed. For example, aspects related to the physical demand scale loaded on two types of factors, showin g that the job content questionnaire measurable two different physical workloads. Although the questionnaire establishes only a scale for physical demand, Karasek & Theorell (23) false that two specific types of physical demand were involved in job tasks (physical execution and physical isometric load). In fact, it is acceptable that the questionnaire includes at least two different kinds of physical demands, as observed in our study.Indeed, this result reinforces the ability of the questionnaire to measure and identify specific characteristics of the work environment. With this perspective, future improvements in the questionnaire should consider the evaluation of these two dimensions separately, quite of only one, as currently suggested. matchless item of the skill discretion scale was also captious. The subscale variety (I get to do a variety of different things in my job), in both the formal and informal groups, was more related to psychological demand aspects than to the skill discretion scale, as expected.The data suggested that doing different things was not related to job enrichment in the studied population in Brazil. In fact, it represents an increase in workload. Moreover, translation difficulties could be considered a potential explanation for these specific results (cultural differences). mavin item related to psychological demand, conflicting demands, loaded on a separate factor for both the formal and informal jobs. It revealed a low correlation of this subscale with other subscales related to psychological demand, which duplicated rather exactly a problem found in studies in other countries (8, 9, 12) for this question.Our results also showed relevant problems with this subscale, reinforcing the hypothesis that changes in this item structure are needed to improve the performance of the psychological demand measurement. For the formal jobs, the item repetitive work did not load on the skill discretion factor, as expected. Similar results were found in studies in other countries (7, 12, 24, 25). The low consistency of this item with the skill discretion subscale could be related to a nonnormal distribution of this aspect. Usually, repetitive work is much more frequent for the lowest skill (9) . The Portuguese version of the job content questionnaire howed a high potency to identify risk to mental health. As predicted by the controldemand model, work with high strain consistently has the highest ostracise effect on mental health for both formal and informal jobs, albeit more strongly for formal jobs. It supports an association between psychological distress and job strain, as pointed out in other studies on mental health (25). In conclusion, the validity and reliability of the Portuguese version of the job content questionnaire is good, and it is performed similarly among workers with formal or informal jobs in Brazil. Future research should address a detailed evaluation f the decision-latitude dimensions in inform al jobs, in particular in relation to skill discretion, which performed on a regular basis among informal workers and in new investigations of psychological demand indicators and their performance. Gender differences form another important aspect to be explored in future studies. Acknowledgments This study was funded by CAPESCoordination for the proceeds of Higher Education Personnel, Brazil, and partially back up by grant D43TW005749, Work and health in Brazil and Mexico from the John E Fogarty Internationl Center of the US National Institutes of Health.SJWEH Suppl 2008, no 6 59 de Araujo & Karasek References 1. Siqueira E. Depend intersection pointthe struggle to control petrochemical hazards in Brazil and the United States. New York (NY) Baywood 2003. 2. Araujo TM, Aquino E, Menezes G, Santos CO, Aguiar L. Work psychosocial aspects and psychological distress among nurses Rev Saude Publica. 20033742433. 3. Alves MGM, Chor D, Faerstein E, Lopes CS, Werneck GL. piddling versio n of the Job Stress Scale Portuguese-language modification. Rev Saude Publica. 20043816471. 4. Karasek R. Job demand, job decision latitude, and mental strain implications for job redesign.Adm Sci Q. 197924285308. 5. Rick J, Briner RB, Daniels K, Perryman S, Guppy A. 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