The DT and PL were used to screen for distress on the majority of eligible patients and carers calling the Cancer Council Queensland Cancer Helpline, and most callers provided valid responses to the instruments. A range of benefits to using the instruments were observed including having an objective, structured and consistent means for distress screening and triage to supportive care services. Reported challenges in using the DT and PL by operators included perceived inappropriateness of the instruments due to the nature of the call or level of caller distress, and the level of operator training.
Operators used the DT and PL on approximately 90% of all calls during the study period, and they were equally administered to male and female cancer patients and carers alike. The DT and PL were more likely to be asked on longer telephone calls, which may relate to the additional time required to administer the DT and PL, or the reason for the call as the perceived distress level and receptiveness of the caller resulted in briefer calls.
All of the operators used the DT and PL the majority of the time, although some operators experienced challenges with using the tools. There was a significant association between telephone operator and DT implementation, suggesting that less experienced operators may experience increased levels of personal discomfort or difficulty in using the tool. Failure to utilise the DT and PL by health professionals has been linked to discomfort discussing emotional or sexual issues . Some operators in the present study found it difficult to incorporate the tools into their conversation, whilst some were uncomfortable or felt inexperienced with the use of the tools. One operator stated: "I believe failure to ask is usually because of my own discomfort in asking that particular caller. My experience is rarely is a caller unhappy to be asked. The more you ask, the easier it gets, more natural it becomes and the more you and the caller benefit". Therefore, ongoing training and support for operators is critical in the implementation of distress screening instruments, and additional support may be required for operators who identify their own discomfort in dealing with difficult emotions.
Operators suggested that there were occasions when administering the DT and PL seemed inappropriate such as when calls were of a practical nature (eg queries about services or equipment collection), or when callers were overtly distressed or newly bereaved. However, screening all callers for distress allows operators to direct or prioritise interventions or referrals [24, 25], determine the exact level of distress for those who appear highly distressed, and provides operators with a rationale for assessing suicidality. Importantly, distress screening also allows operators to meet the needs of callers who otherwise may not receive emotional support. Finally, previous research has shown that patients are more satisfied with information services when emotional issues are discussed .
Operators also questioned whether the DT and PL provided additional information during the course of the call. Some felt that they were able to gauge how well a caller was coping through their own clinical judgement. In some cases this may have been true, such as when callers were quite explicit in describing their current coping and support needs. However, research has shown that health professionals do not assess patient distress accurately when it is not explicit [17, 24, 25]. Use of a distress screening tool in clinical practice ensures that all eligible callers are assessed and triaged, even if they are not showing overt signs of distress. It also allows for a baseline measurement of coping, another advantage identified by operators.
Some operators suggested that use of the term "distress" and the numeric scale were were confusing for some callers. One noted that certain callers (the elderly and those or low socio-economic status) appeared to have difficulty with the numeric scale and they had to rephrase the scale. This is an obvious concern when using a standardised measure with validated cut-offs. Some callers did not respond to the DT because they chose to describe their distress instead eg "doing OK". One way to overcome this barrier would be to match the numbers with descriptors of that level of distress. One operator said men were confused with the term "distress". Confusion or concern about whether patients understand this term has been discussed in other studies [17, 24]. One group suggested a definition of distress be included in the questionnaire . Other studies considered using other terms such as "mood" . However, the term "distress" was selected by Roth et al. (1998) because it was thought to be less stigmatising and more acceptable to people . It may be useful for further research to investigate whether certain sub-groups or people do indeed have difficulty with the numeric scale or terms used in the DT.
Content analysis of responses that did not fit into the existing PL categories indicated that additional categories may be useful. Decision support and information concerns were raised by some callers. Information concerns have been suggested as an additional PL category in other research  but extending this category to include decision making or decision support may also be useful. "Adjusting to illness" and "feeling alone" also appear to be valid additions to the PL as recommended by Graves et al. (2007) . Other items worth considering in the Emotional Problems category relate to loss of independence or control, grief and bereavement. Practical problems relating to finance and the health system or health professionals could also be added. However, some considerations need to be taken into account with any changes to the PL. Firstly; it could be argued that a separate "carer" PL be developed. For instance, the listed physical problems only relate to patients. Also, there are likely to be issues specifically related to carer burden and bereavement. Secondly, additions to the PL have to be considered in its purpose as a "brief" screening tool. Each item should need to justify its inclusion and more research is required to identify whether the items are the most common problems experienced and importantly whether they assist appropriate referral. The PL may benefit from focus group research with cancer patients and carers.
The current study had a number of limitations. The DT and PL are predominantly utilised as self-administered instruments, although in the current study they were used in a cancer helpline context by telephone. This may reduce their generalisability to other settings. The operators did not always provide enough detail in their data collection to accurately categorise the "other" problems identified during PL administration. Whilst caller's response to the DT and PL were recorded by operators, callers were not specifically requested to detail their perception of the tools. Finally, limited socio-demographic information was collected from helpline callers as the purpose of the telephone call was to provide assistance rather than focus on data collection for research purposes.