function showhelp(grouping, id) { var help_area = document.getElementById('help_area'); var text = ""; if (grouping == 'diet') { switch (id) { case '1': text = "Accuracy dependent on number of days of recording "; break; case '2': text = "Single 24-hour recalls are less useful than repeated recall due to day-to-day variability in intake"; break; case '2a': text = "Single 24-hour recall not appropriate for analysing individual intake"; break; case '3': text = "The length of FFQs can vary and may be based on an extensive list of food items or a relatively short list of specific foods which are a major source of a nutrient(s) of particular interest. The length of the food-list typically ranges from 20 to 200 items. FFQs can be open-ended where respondents may record consumption of foods not on the food list (Open FFQ) or confined to the food list (Closed FFQ). Long FFQ is > 150 items"; break; case '4': text = "Several of the dietary assessment methods can be used to estimate food and nutrient intakes of specific interest eaten on a regular basis by the population being investigated e.g. calcium intake, fruit and vegetable intake, saturated fat consumption etc"; break; case '5': text = "Diet diaries/repeat 24-hour recalls reflect a snapshot in time and cannot be used to assess the intake of nutrients (e.g. retinol) and foods (e.g. oily fish) which are eaten infrequently"; break; case '5a': text = "While FFQs are not appropriate for energy on most nutrients they can be suitable for specific foods or for nutrients found in a small number of foods"; break; case '6': text = "Diet diaries/repeat 24-hour recalls are a snapshot in time. Habitual diet may only be assessed if the diary/24-hour recall is repeated on several occasions during a period of several months or a year"; break; case '7': text = "Only if collected at the younger age"; break; case '8': text = "FFQs have been used to assess past diet but may not be suitable for the distant past because of problems with memory or inappropriate foods in list"; break; case '9': text = "Day to day variation can be assessed if several days of dietary intake are recorded "; break; case '10': text = "Columns can be added to the diaries to collect information on the social context and environment at eating occasions"; break; case '11': text = "Questions can be added to the interview to collect information on the social context and environment at eating occasions"; break; case '12': text = "Diet diaries/24-hour recalls reflect a snapshot in time and cannot be used to assess the intake of nutrients (e.g. retinol) and foods (e.g. oily fish) which are eaten infrequently."; break; case '13': text = "Diaries are resource intensive and impose substantial subject burden which may affect response rate, limiting usefulness for large population studies"; break; case '13a': text = "24-hour dietary recalls are appropriate for use in large study samples (e.g. NHANES)."; break; case '14': text = "FFQs have been used in large prospective cohort studies (e.g. EPIC)"; break; case '15': text = "Developing a new FFQ for use in a study is more costly than adapting an existing questionnaire but may be necessary if a suitable questionnaire does not exist. More expensive to develop FFQs for specific subgroups"; break; case '16': text = "Can be expensive to administer due to high interviewer burden. Telephone interviews can help to reduce costs"; break; case '17': text = "FFQs can be analysed comparatively easily through use of machine-readable questionnaires or computer-administered questionnaires containing costs"; break; case '18': text = "Trained staff are required to interpret the diaries and produce nutrient data making it costly in staff time and equipment"; break; case '19': text = "Repeat 24-hour recalls increase cost of analysis"; break; case '20': text = "Participant burden will increase with the length of the questionnaire"; break; case '21': text = "A large number of visits/phone calls increases participant burden. The burden on the participant increases with the number of repeated 24-hour recalls completed"; break; case '22': text = "Collecting dietary data in children can be problematic if the child goes to school or has other carers. A suitable method should allow intakes to be recorded away from home"; break; case '23': text = "If self-complete, need literacy/numeracy"; break; default: text = ""; break; } } else if(grouping == 'physical') { switch (id) { case '1': text = "Self-report methods are liable to misreporting especially among younger age groups. Occupational activity and structured exercise are usually relatively accurately reported whereas other "everyday life" activities are prone to recall error. "; break; case '2': text = "Intensity, duration and frequency of physical activity are more precisely assessed with objective measures of physical activity (e.g. accelerometry, heart rate monitoring or combined sensing)"; break; case '3': text = "Generally underestimates energy expenditure for high intensity activities and for specific activities with limited acceleration of the torso (e.g. bicycling, stair climbing, walking uphill, rowing) and load carrying. "; break; case '4': text = "At lower levels of intensity, heart rate monitoring can be influenced by environmental (e.g. temperature) and emotional (e.g. stress) factors and therefore less accurate at estimating energy expenditure."; break; case '5': text = "Combines advantages of a physiological measure of heart rate and body movement measured by accelerometry. "; break; case '5a': text = "Energy expenditure can be calculated from objectively measured data on frequency, intensity and duration. Energy expenditure estimates from self-report are generally less valid than objective methods."; break; case '6': text = "Compendium of physical activity provides average values of energy cost of different activities. Not as accurate as an objective measure of energy expenditure, but allows an estimation of EE. "; break; case '7': text = "Possible but heavily influenced by which prediction equation is used."; break; case '8': text = "Heart rate monitoring does not provide accurate energy expenditure estimate at low-intensity."; break; case '9': text = "High frequency accelerometry and multi-sensor systems may provide information on the context of physical activity."; break; case '10': text = "In combination with other methods, GPS data may provide information on domains of activity. "; break; case '10a': text = "Location data may allow inference on type of activity (e.g. in combination with Geographical Information Systems, GIS) "; break; case '11': text = "Current commercially available systems are based on at least two sensor locations on the body, which may not be feasible for all research settings"; break; case '12': text = "Location (including altitude) data may, if stored in reasonably high time resolution, yield information on intensity, frequency, duration and total volume of activity but only when a clean GPS signal is available - there are still challenges to be overcome in urban settings and indoors."; break; case '13': text = "It may be possible to infer type of activity such as computer work by pattern recognition of for example wrist acceleration."; break; case '14': text = "It may be possible to detect general sleep pattern from combined heart rate and movement data."; break; case '15': text = "Limb acceleration has been used to detect sleep stages. However this depends on some prior annotation of sleep period. It is possible that this may be developed to detect overall sleep."; break; case '16': text = "Assuming a good enough GPS signal is obtained, it is possible, by combination with GIS to infer if the person is in a motor vehicle on the road, on a train, or on a boat but the actual level of activity depends on the physical restriction of the vehicle and whether the person is driving or not."; break; case '16a': text = "Sedentary behaviours may be defined as engagement in pursuits that require expending low amounts of energy i.e. >0.9 (sleeping) but <2.0 (sitting) Metabolic Equivalents (METS)"; break; case '17': text = "Questionnaires and diaries are generally not regarded as suitable for young children therefore proxy reports are often used. "; break; case '18': text = "There are specific problems with the accuracy of questionnaire-derived data from young children because of cognitive limitations of those aged < 10 years. "; break; default: text = ""; break; } } if(text !="") { help_area.style.visibility = 'visible'; help_area.style.width = '200px'; help_area.style.position = 'fixed'; help_area.style.backgroundColor='#FFFFFF'; help_area.style.border= '1px solid #000000'; help_area.style.textAlign='left'; mousey = mousey+15; mousex = mousex -150; help_area.style.left = mousex + 'px'; help_area.style.top = mousey +'px'; help_area.innerHTML = text; } else{ help_area.style.visibility = 'hidden'; } } function hidehelp() { var help_area = document.getElementById('help_area'); help_area.style.visibility = 'hidden'; } // ------------------------------------------------ // mouse position detection // // Detect if the browser is IE or not. var IE = document.all ? true : false // If it is not IE, we assume that the browser is NS. if (!IE) document.captureEvents(Event.MOUSEMOVE) // If NS -- that is, !IE -- then set // up for mouse capture document.onmousemove = getMouseXY; // Set-up to use getMouseXY function // onMouseMove // Temporary variables to hold mouse x-y pos.s var mousex = 0; var mousey = 0; // Main function to retrieve mouse x-y pos.s function getMouseXY(e) { if (IE) { // grab the x-y pos.s if browser is IE mousex = event.clientX + document.body.scrollLeft mousey = event.clientY + document.body.scrollTop } else { // grab the x-y pos.s if browser is NS mousex = e.pageX + window.pageXOffset mousey = e.pageY - window.pageYOffset //alert(mousey +" : "+mousex); } // catch possible negative values in NS4 if (mousex < 0) { mousex = 0 } if (mousey < 0) { mousey = 0 } return true }