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David Whiteman

Publications and source records attributed to David Whiteman.

9 recordsLinked to original sources
PubMed2026

Years of life lost in patients with a false-negative diagnosis of primary melanoma. A prospective study of the German Central Malignant Melanoma Registry involving 9063 patients over 28 years.

A false-negative diagnosis of cancer can lead to a delay in effective treatment and a poorer prognosis. Here, we use the example of cutaneous melanoma to examine how many years of life are lost after a false-negative diagnosis compared to a primarily correct diagnosis. From 1996 to 2015, 9,063 patients are prospectively registered in the German Central Malignant Melanoma Registry and followed up until December 2023. A false-negative diagnosis is found in 206 (2.3%) patients. The median time to correct diagnosis is 24.0 months. The 10-year recurrence-free survival probabilities are 32.9% for false-negative diagnoses and 76.2% for correct diagnoses (p&#x2009;<&#x2009;0.001). The 10-year melanoma-specific survival probabilities are 62.1% versus 85.0% (p&#x2009;<&#x2009;0.001). On average, each person with an initial false-negative diagnosis loses 8.2 years of life compared to people with a correct diagnosis. This high number of years of life lost raises the question of whether similar results also apply to other types of cancer.

Humans↗
PubMed2006

Solaria use in Queensland, Australia.

OBJECTIVE: To describe the demographics of solarium users and the correlates of solarium use in Queensland. METHODS: A cross-sectional survey of 9419 Queensland residents was conducted via an anonymous computer-assisted telephone interview. RESULTS: Overall, 8.8% of the respondents had ever used a solarium and less than 1% had used a solarium in the previous year. Results indicated that users were more likely to be female and younger than non-users, and less than half of the users signed a consent form, suggesting that they had not been made aware of the associated risks by operators. CONCLUSIONS: The Queensland Cancer Risk Study was one of the first population-based studies to address solarium use in this State and highlights that the use of solariums in Queensland is low in comparison to other countries. IMPLICATIONS: There is no regulation of compliance with guidelines. It may become necessary to make compliance with the guidelines mandatory to effectively communicate the associated risks.

Adult↗
PubMed2006

The Queensland Cancer Risk Study: behavioural risk factor results.

OBJECTIVE: To describe the population prevalence of key cancer risk behaviours in Queensland. METHODS: The Queensland Cancer Risk Study was a population-based survey of 9,419 Queensland residents aged 20-75 years. Information was collected through an anonymous, computer-assisted telephone interview between February and November 2004. Outcome measures included tobacco smoking, alcohol consumption, sun-tanning and sunburn, obesity, physical inactivity and poor diet, weighted by age, gender and geographic region. RESULTS: Prevalence of current smoking was 25.2% for males and 20.8% for females and was highest in the 20-39 year age group and in rural/remote areas. Two-thirds of participants regularly drank alcohol; of these, 63% consumed excessive amounts of alcohol. Excessive sun exposure is still a problem; 70% of Queenslanders reported an episode of sunburn and 12% reported attempting to get a suntan in the past year. More than half of the respondents (53.9%) were above the healthy weight range, and 17.1% of males and 18.4% of females were obese. Just over 40% of Queensland adults reported having insufficient levels of physical activity. Fewer than half of the participants met recommended levels of fruit or vegetable consumption. CONCLUSIONS AND IMPLICATIONS: The majority of Queensland adults exhibit known, modifiable cancer risk behaviours. These results suggest that continuing efforts to reduce the prevalence of these risk factors are warranted. Specifically, significant gains could be made by targeting behaviour change programs at younger Queenslanders (aged 20-39 years), men, and those living in remote/ very remote areas of Queensland.

Adult↗
PubMed2003

Batch process monitoring using on-line MIR spectroscopy.

Many high quality products are produced in a batch wise manner. One of the characteristics of a batch process is the recipe driven nature. By repeating the recipe in an identical manner a desired end-product is obtained. However, in spite of repeating the recipe in an identical manner, process differences occur. These differences can be caused by a change of feed stock supplier or impurities in the process. Because of this, differences might occur in the end-product quality or unsafe process situations arise. Therefore, the need to monitor an industrial batch process exists. An industrial process is usually monitored by process measurements such as pressures and temperatures. Nowadays, due to technical developments, spectroscopy is more and more used for process monitoring. Spectroscopic measurements have the advantage of giving a direct chemical insight in the process. Multivariate statistical process control (MSPC) is a statistical way of monitoring the behaviour of a process. Combining spectroscopic measurements with MSPC will notice process perturbations or process deviations from normal operating conditions in a very simple manner. In the following an application is given of batch process monitoring. It is shown how a calibration model is developed and used with the principles of MSPC. Statistical control charts are developed and used to detect batches with a process upset.

Journal Article↗
PubMed2002

Typical variability and evaluation of sources of variability in drug dissolution testing.

To investigate variability in dissolution testing an international collaborative study was performed by 29 laboratories. Glibenclamide (glyburide) tablets were used in the investigation in which multipoint dissolution profiles were established using USP paddle apparatus. In contrast to a previous report, the variability of the glibenclamide dissolution data was significantly lower. Total variances (s(2)) were found to range from 18.34-44.18, Between Laboratory and Between Analyst variances (synthetic value) ranged from 12.9-38.7 and the Within Analyst variances ranged from 5.08-5.78. The dissolution profiles and corresponding variances obtained by laboratories with little or no experience in glibenclamide dissolution testing were similar to those obtained by more experienced laboratories, indicating that the test, especially when designed as multiple point dissolution testing, is sufficiently robust and capable of identifying differences in a manufacturing process or drug formulation. The smallest statistically detectable mean difference between two dissolution runs was calculated (95% CI) to be 7% for one analyst, or 5% if two analysts were to perform the dissolution tests.

Drug Evaluation, Preclinical↗
PubMed2002

Does cigarette smoking increase time to conception?

Data are reported on the relationship between cigarette smoking and other health-related behaviours and time to conception in a population-based sample of women who acted as a control group in a case-control study of twinning. Women who continued to smoke close to the time of conception took significantly longer to become pregnant than women who never smoked or stopped smoking before the year during which they attempted to conceive. A hierarchical regression analysis performed on time-to-conception data in women who continued to smoke in the year before conception provided weak evidence for a dose-response relationship between time to conception and number of cigarettes smoked per day. No significant relationships were found between time to conception and other health-related behaviours.

Adult↗