Estimates of Current Capacity for Diagnosing Alzheimer's Disease in Sweden and the Need to Expand Specialist Numbers.

BACKGROUND: The emergence of disease-modifying Alzheimer's (AD) treatments provides new hope to patients and families but concerns have been raised about the preparedness of healthcare systems to provide timely access to such treatments because of a combination of a complex diagnostic process and a large prevalent pool. OBJECTIVES: We assess the preparedness of Sweden, a high-income country known for its dementia-friendly policies, to diagnose AD patients eligible for treatment within a six-month window, given current capacity for specialist evaluations and biomarker testing. We calculate the investment requirements for Sweden to achieve this target over a timeframe of 20 years. DESIGN: Desk research to identify data for population, mortality, disease burden, cost of services and current capacity, expert consultation to inform assumptions about patient journey, and use of a Markov model to predict waiting times. The model simulates the patients' journey through different evaluation stages: initial evaluation by a primary care specialist, neurocognitive testing by an AD specialist, and confirmatory biomarker testing with PET scanning or cerebrospinal fluid (CSF) testing. The model assumes specialist appointments and PET scans are capacity constrained, and patients progress from cognitively normal to MCI and from MCI to dementia in the resulting waiting times. MEASUREMENTS: Projected waiting times for diagnosis of eligibility for disease-modifying Alzheimer's treatment from 2023 to 2042 assuming current capacity, assuming 20% of Swedish residents aged 60 years and above would seek an evaluation for cognitive decline. Investments required to scale capacity up to reach target of providing diagnosis within six months on average. RESULTS: Initial average waiting times for AD specialist appointments would be around 21 months in 2023 and remain around 55 months through 2042, as demand would continue to outstrip supply throughout the 20-year model horizon. Waiting times for biomarker testing would be stable at less than four weeks, as patients would be held up in the queue for their first specialist consultations, and use of CSF testing is widely accepted in Sweden. An additional 25% of AD specialists would have to be added above the current growth trend to reduce waiting times to less than 6 months at an average annual cost of approximately 805 million SEK. The increased cost of volume of biomarker testing would amount to about 106 million SEK per year. CONCLUSIONS: At current capacity, the Swedish healthcare system is unable to provide timely diagnosis of patients eligible for disease-modifying AD treatment. Although future diagnostic technologies, such as digital cognitive assessments and blood tests for the AD pathology, might decrease demand for capacity-constrained services, substantial investments will be required to meet a target of less than six months of waiting time for a diagnosis.

Screening over Speech in Unselected Populations for Clinical Trials in AD (PROSPECT-AD): Study Design and Protocol.

BACKGROUND: Speech impairments are an early feature of Alzheimer's disease (AD) and consequently, analysing speech performance is a promising new digital biomarker for AD screening. Future clinical AD trials on disease modifying drugs will require a shift to very early identification of individuals at risk of dementia. Hence, digital markers of language and speech may offer a method for screening of at-risk populations that are at the earliest stages of AD, eventually in combination with advanced machine learning. To this end, we developed a screening battery consisting of speech-based neurocognitive tests. The automated test performs a remote primary screening using a simple telephone. OBJECTIVES: PROSPECT-AD aims to validate speech biomarkers for identification of individuals with early signs of AD and monitor their longitudinal course through access to well-phenotyped cohorts. DESIGN: PROSPECT-AD leverages ongoing cohorts such as EPAD (UK), DESCRIBE and DELCODE (Germany), and BioFINDER Primary Care (Sweden) and Beta-AARC (Spain) by adding a collection of speech data over the telephone to existing longitudinal follow-ups. Participants at risk of dementia are recruited from existing parent cohorts across Europe to form an AD 'probability-spectrum', i.e., individuals with a low risk to high risk of developing AD dementia. The characterization of cognition, biomarker and risk factor (genetic and environmental) status of each research participants over time combined with audio recordings of speech samples will provide a well-phenotyped population for comparing novel speech markers with current gold standard biomarkers and cognitive scores. PARTICIPANTS: N= 1000 participants aged 50 or older will be included in total, with a clinical dementia rating scale (CDR) score of 0 or 0.5. The study protocol is planned to run according to sites between 12 and 18 months. MEASUREMENTS: The speech protocol includes the following neurocognitive tests which will be administered remotely: Word List [Memory Function], Verbal Fluency [Executive Functions] and spontaneous free speech [Psychological and/ or behavioral symptoms]. Speech features on the linguistic and paralinguistic level will be extracted from the recordings and compared to data from CSF and blood biomarkers, neuroimaging, neuropsychological evaluations, genetic profiles, and family history. Primary candidate marker from speech will be a combination of most significant features in comparison to biomarkers as reference measure. Machine learning and computational techniques will be employed to identify the most significant speech biomarkers that could represent an early indicator of AD pathology. Furthermore, based on the analysis of speech performances, models will be trained to predict cognitive decline and disease progression across the AD continuum. CONCLUSION: The outcome of PROSPECT-AD may support AD drug development research as well as primary or tertiary prevention of dementia by providing a validated tool using a remote approach for identifying individuals at risk of dementia and monitoring individuals over time, either in a screening context or in clinical trials.

Efficacy of memantine in PDD and DLB: an extension study including washout and open-label treatment.

OBJECTIVE: This 30-week extension trial was a continuation of the first double-blind randomized controlled trial (RCT) to study memantine in dementia with Lewy bodies (DLB) and Parkinson's disease dementia (PDD). The objective was to evaluate the presence of recurrence of symptoms upon drug withdrawal. Furthermore, the aim was to explore washout dynamics in order to inform clinical practice. METHODS: Patients were enrolled from psychiatric, memory and neurological outpatient clinics in Norway, Sweden and the UK. The trial comprised a 4-week washout period and a 26-week open-label treatment period. Outcome measures were presence of recurrence of symptom upon drug withdrawal, Clinical Global Impression of Change (CGIC) and modified motor Unified Parkinson's Disease Rating Scale (UPDRS). RESULTS: recurrence of symptoms occurred more frequently (p=0.04) in patients receiving memantine (58%) than in patients receiving placebo (25%). There was a significant global deterioration (p=0.0003) during washout within the memantine group as measured by CGIC. The patients seemed to recover during the open-label treatment, however these findings were non-significant. CONCLUSIONS: The findings inform clinical practice that any possible memantine-associated benefits might be rapidly lost after drug withdrawal. The magnitude of deterioration suggests a symptomatic rather than a disease-modifying effect of the drug. Open-label results should merely be considered inspiration for future trials.

An 8-year follow-up of removable partial denture treatment performed by the Public Dental Health Service in a Swedish county.

The aim of the present study was to evaluate clasp-retained removable partial dentures (RPDs) made in the Public Dental Health Service (PDHS) in Orebro County in 1989. Records from all 25 PDHS clinics concerning RPDs from 1989 were collected after eight years and available information was registered. The entire material consisted of 447 RPDs (both attachment-retained and clasp-retained RPDs) in 387 patients. Of the 316 clasp-retained RPDs that were traceable, 208 were followed from 1989 to 1997. In most instances, information on diagnoses, alternative treatments and design of the RPDs was lacking. One hundred and thirty-two (42%) of the 316 clasp-retained RPDs were judged to still be in use in 1997 while 75 were not in use. The main reason for ceased use was dislike by the patient. There were 108 clasp-retained RPDs that were not possible to follow from 1989 to 1997 because there were no notes regarding follow-ups in the records. The most common technical complications noted in the records during the observation period were clasp fractures and loosened artificial teeth.

Influence of dental care systems on dental status. A comparison between two countries with different systems but similar living standards.

OBJECTIVE: To evaluate the influence of two different dental care systems on dental status, taking into account relevant socio-economic factors. BASIC RESEARCH DESIGN: Questionnaire studies on randomly sampled subjects in Denmark and Sweden using questionnaire forms as identical as possible with regard to the different languages. SETTING: The studies were performed late in 1998 in both countries. PARTICIPANTS: Questionnaires were sent to 1,175 subjects aged 45-69 years in Denmark (response rate 73%) and to 1,001 subjects aged 55-79 years in Sweden (response rate 67%). MAIN OUTCOME MEASURES: Questions about dental status and about socioeconomic factors and attitudes toward dental care were included. In logistic regression models, various dichotomies of dental conditions were used as dependent variables. State (Denmark vs. Sweden) was used as an independent variable together with socioeconomic factors and attitudes. RESULTS: There were great differences between the countries in dental status. In the regression model with 'wearing removable denture(s)' as the dependent variable, state was the strongest predictor with an OR of above 4.1 for Denmark compared to Sweden. much stronger than variables such as age, income, education and residence. CONCLUSION: The results indicate that the Swedish dental care system has been superior to the Danish one regarding dental status in middle aged and older populations in these two countries.

Changes in dental conditions during a decade in a middle-aged and older Swedish population.

A questionnaire measuring dental conditions was sent to 2708 individuals aged 55 79 years in Orebro County, who about 10 years earlier had been randomly selected for a similar study. The response rate was 68% (1848 individuals). Of those, 1665 had participated also in the 1989 study. The objectives were to study changes in dental conditions having occurred during a decade and to evaluate whether impairment in dental conditions among the participants had resulted in prosthodontic treatments. Only small changes in dental conditions were registered among those who participated both in 1989 and in 1999. Loss of a single tooth was the most frequently reported change. Ten per cent fewer reported that they had all teeth remaining in 1999 compared with conditions in 1989. The number of subjects wearing removable dentures increased only slightly. Although the reported changes in dental conditions were small, there had been a need for prosthodontic treatment in many of the subjects. Ten percent of the subjects reported that they had received FPD treatment during the past 10 years. To conclude, the present study showed that only small changes in dental conditions had occurred among the participants during a decade. Nevertheless, a substantial increase in the prevalence of prosthodontic appliances, especially of fixed restorations, was noted.

Dental conditions in middle-aged and older people in Denmark and Sweden: a comparative study of the influence of socioeconomic and attitudinal factors.

In 1998-99 two parallel questionnaire studies were performed in Denmark and Sweden. In Denmark the age group was 45-69 years and in Sweden 55-79 years. One aim was to study the influence of socioeconomic and attitudinal factors on dental status in the two countries. For the comparable age groups 55-69 years there was a striking difference in dental conditions between the countries. In Sweden, 72% had either all teeth remaining, missing teeth replaced by fixed prosthodontics, or only one or two single missing teeth not replaced. The corresponding figure for Denmark was 44%. Among Danes, 34% were wearing removable denture(s) or were edentulous in one jaw or both jaws, compared with 15%, among Swedes. In logistic regression models, higher income and longer education were significantly associated with the best dental status categories in Denmark but not in Sweden. In the model with wearing removable denture(s) as the dependent variable, lower income and lower education level showed a significant influence for the Danes. In Sweden, lower income showed a significant influence but education level was insignificant. In both Denmark and Sweden, a positive attitude toward the importance of dental appearance was associated with an increased risk of wearing removable denture(s).

Five-year results with fixed complete-arch mandibular prostheses supported by 4 implants.

This study examined whether it is possible to restore an edentulous mandible with a complete-arch fixed prosthesis retained by only 4 implants without decreasing the survival rate. One hundred nineteen patients received complete-arch mandibular prostheses retained by 4 implants. Most patients were followed for 3 years or more. All patients followed a routine protocol, including annual check-ups and regular radiographic examinations. Twenty-one patients dropped out. Radiographic measurements used the threads of the implants as a basis for comparison. No indication was found that the number of supporting implants could have influenced the observed frequency of technical and surgical complications. Three implants were lost, 2 after 1 year and 1 after 5 years. A statistically significant difference in bone loss between the mesial and distal implants was found. The number of fractured resin teeth in mandibular prostheses was higher when patients had an implant-supported prosthesis in the maxilla. The present study revealed an implant survival rate of 98.6% after 5 years. Therefore, it was concluded that there may not be a need for more than 4 implants to support a fixed mandibular prosthesis, when implants at least 10 mm long can be used.

Dentist-related factors influencing the amount of prosthodontic treatment provided.

OBJECTIVES: To evaluate, using multivariate methods, the associations between indicators of the amount of prosthodontic treatment and dentist-related factors. METHODS: Questionnaires were sent to a random sample of 2,059 general dentists, response rate was 76%. Two indicators of prosthodontic activity were used as dependent variables: 1) reported weekly working hours used for prosthodontics and 2) reported numbers of produced single crowns, fixed partial dentures, and removable dentures. Independent variables were 'social and demographic attributes', 'job situation' and 'attitudes of dentists'. Multiple regression analysis was used in models with continuous dependent variables and logistic regression analysis for categorical dependent variables. RESULTS: 'Weekly working hours used for dental care of adults' showed a strong association in all models with the dependent variable 'weekly working hours used for prosthodontics'. Male dentists provided more prosthodontic services than female dentists, even if reporting less time used for prosthodontics. Private practitioners produced more fixed prosthodontics than dentists employed in the public dental health service. Dentists in the public dental health service reported a higher production of removable dentures than private practitioners. CONCLUSION: The results indicate that factors, besides those in the rational clinical model for decision-making, e.g. gender and delivery system, play a role in the provision of prosthodontic services.

Prosthodontic decision making among general dentists in Sweden. III: The choice between fixed partial dentures and single implants.

PURPOSE: The purpose of this study was to describe how dentists evaluated the importance of various items related to a treatment choice between fixed partial dentures (FPD) and single implants, and to analyze if the differences could be explained by dentist-related variables such as social and demographic attributes, job situation, and attitudes. MATERIALS AND METHODS: Questionnaires were sent to a random sample of 2,059 Swedish general dentists, with a response rate of 76%. In the questionnaire, the choice between an FPD and a single-implant restoration in a clinical situation was presented. Fifteen items were constructed and the dentists were asked to mark on visual analogue scales the relative importance he or she gave the different items. The items were analyzed through principal components analysis, where a three-factor solution was obtained; the factors were labeled as "time," "health," and "comfort." The factors were run as dependent variables in multiple regression analyses. RESULTS: The items evaluated as most important were "prognosis for delivered treatment" and "patient's wish." Large individual differences were seen, but the differences between groups of dentists were small. Male dentists considered the "health" and the "comfort" factors to be more important compared to female dentists. The attitudinal variable "patient information" was significantly associated with the "time" factor and, inversely, with the "comfort" factor. CONCLUSION: Differences between individuals were great, but between groups of dentists the differences were only minor. Multivariately, the attitudinal variable "patient information" showed significant associations with the "time" and the "comfort" factors. Dentist-related variables explained little of the variations. The results further indicated a low personal knowledge concerning implant treatments. Psychologic methods might explain more of the individual differences in prosthodontic decision making, but these are not easily used in a questionnaire study.

Social equality and dental conditions--a study of an adult population in Southern Sweden.

This study aimed to: describe dental conditions--focusing on prosthodontic variables--in relation to social conditions in the late 1990s in an adult population of Southern Sweden, evaluate if a change could be traced in the pattern of socioeconomic influences on dental conditions, and study if various attitudes toward dental care were associated with social as well as dental conditions. The study was based on questionnaire responses. Significant differences in dental conditions and denture prevalence were found for age and education. To a majority of the sample it was very important to have own teeth and/or fixed restorations and the opportunity to attend regular dental care. The cost for dental care was very important for 52% of the sample especially for men, those with low education, and those wearing removable denture. Need for dental care that could not be provided for because of the costs was experienced by 9%. Eighteen percent stated that they once or more had refrained from dental care because of the cost. Those with removable dentures and low education dominated. Besides socioeconomic differences in dental conditions, there were sociodental differences in attitudes concerning the importance of costs, self-estimated needs, and cost-barriers for dental care.

Communication during prosthodontic treatment--dentist, patient, and dental nurse.

PURPOSE: This study described and explored verbal communication during prosthodontic treatment. MATERIALS AND METHODS: Sixty-one patients and 15 dentists participated. Sixty-one prosthetic treatment periods, during which fixed tooth- or implant-supported prostheses were placed, were followed. One visit during each treatment period was audio recorded. The recorded verbal communication was analyzed with the Roter Interaction Analysis System-dental. The inter-rater reliability was 95% to 97% for utterance classification and kappa = 0.71 to 0.78 for categorization definition. RESULTS: There were 43,663 utterances available for analysis. Of those, 59% was dentist communication, 28% was patient communication, and 10% was dental nurse communication. Other persons, e.g., dental technicians, contributed with 3%. The dentist-patient communication contained more task-focused than socioemotional behaviors. Female patients used socioemotional talk to a greater extent than did the male patients. Dentists and patients of different genders communicated more overall, especially male dentists with female patients. The age difference between dentist and patient had no effect on the amount or type of communication. The dental nurse talked slightly more with male patients. CONCLUSION: When different genders met there was more communication, and the talk was more socioemotional when the patient was female.

Congruence between self-reported and actually provided prosthodontic services among Swedish dentists.

The purpose of this study, comprising two parts, was to investigate the congruence between answers given by general dentists in questionnaires concerning prosthodontic services and the recorded information on the services actually performed by each dentist. In Part I it is investigated whether questionnaire reports of weekly working hours devoted to prosthodontics can be used as indicators of actual prosthodontic production. Part II deals with the dentists' self-reported numbers of single crowns, fixed partial dentures (FPDs), and removable dentures. These reported services are compared with the services actually provided. Part I: A regression analysis indicates a lacking precision for the individual dentist, indicated by a relatively low explained variance (R2 = 0.20). However, a highly significant association is seen between the two production measures (P = 0.000). Part II: The congruence between stated and actually provided services is higher for single crowns and removable dentures than for FPDs. Bivariate regression models are statistically significant for all three services. In Part II, the reported weekly working hours used for prosthodontics covaries significantly with prosthodontic production, but the association is not as strong as in Part I. Although the precision in both Part I and Part II is low for the individual dentist, the questionnaire measure is found to be useful as an indicator in a population of dentists. It is concluded that the questionnaire data can be used as reasonably valid expressions of prosthodontic activity in population-oriented analyses among general dentists.

General dentists' attitudes toward delegation, information, and patient influence in a prosthodontic context.

PURPOSE: The aim of this study was to investigate attitudes among general dentists in Sweden in relation to gender, age, prosthodontic activity, and dental delivery system (private or public). MATERIALS AND METHODS: Questionnaires were sent to a random sample of 2,059 dentists, and a response rate of 76% (1,567 dentists) was achieved. Among those who responded, 50% were private practitioners and 50% were publicly employed practitioners; 42% were female and 58% were male. The questionnaire contained 10 statements aimed at measuring attitudes. Their dimensionality was analyzed using principal components analysis. The resulting factors were related to delivery system (public or private), gender, age, job satisfaction, and weekly working hours used for prosthodontics in multiple regression models. RESULTS: There was a wide variation in the answers to the statements, indicating great individual differences in opinions among dentists. Several distributions differed with respect to gender and delivery system, but the mean differences between various groups of dentists were small. The most affirmative attitude was shown for delegation of impression taking to auxiliaries (mean 6.7; SD 1.8), and the most negative attitude was shown for close cooperation between dentists (mean 1.8; SD 1.4). The factor analysis gave 3 factors, with a variance explanation of 57%. Regression models for the 3 attitude dimensions ("patient influence," "delegation," and "patient information") showed that female dentists felt more positive about delegation and information than male dentists. The explained variance was very low for all 3 models and varied from 0.01 to 0.05. CONCLUSION: Although the differences in attitudes between various groups of dentists were statistically significant, these differences were small in relation to the large variation in attitudes among individual dentists.

Laser-welded titanium frameworks for implant-supported fixed prostheses: a 5-year report.

The 5-year results from a multicenter study of implant-supported, laser-welded titanium frameworks are reported here as a complement to earlier reported 2-year results. Implant survival rates were satisfactory for patients with titanium frameworks and for a control group of patients with gold-alloy frameworks. At the 5-year review, more patients with titanium frameworks had lost implants than the patients with gold-alloy frameworks, but this difference was not statistically significant. More fractures of the titanium frameworks occurred, compared to the gold-alloy frameworks; again, this difference was not statistically significant. No significant differences in marginal bone levels were found between the 2 groups of patients. Slightly more fractures of artificial teeth occurred in patients with titanium frameworks than in patients with gold-alloy frameworks. Overall results for the titanium frameworks after 5 years in function are encouraging.

Prosthodontic decision making among general dentists in Sweden. I: The choice between crown therapy and filling.

PURPOSE: The purpose of this study was to analyze dentists' evaluations of factors related to the choice between crown therapy and filling and to possibly explain this by social and demographic attributes, job situation, and dentists' attitudes. MATERIALS AND METHODS: Questionnaires were sent to a random sample of 2,059 Swedish dentists. The response rate was 76%. In the questionnaire the choice between crown therapy and filling in a clinical situation was presented. The dentists were asked to mark their assessments of the relative importance of the different items on 14-item visual analogue scales (VAS). Multiple regressions were run for all 14 items. RESULTS: Large individual variations were seen among the dentists regarding the stated importance of the various items. The items rated as the most important were "patient's wish" and "treatment prognosis," and the items rated as least important were "treatment time required" and "number of visits required for treatment." The differences between groups were small, and for no item exceeded 0.7 step on the 8-grade VAS scale. No data reduction was possible using principal components analysis. CONCLUSION: The study showed great variations among individual dentists. The dentist-related factors explained little of the variance. The results indicated that the questionnaire instrument did not fully capture the real influences on the treatment choice between a filling and an artificial crown.

Prosthodontic decision making among general dentists in Sweden. II: The choice between fixed and removable partial dentures.

PURPOSE: The purpose of this study was to describe how dentists evaluated various items related to a treatment choice between fixed partial dentures (FPD) and removable partial dentures (RPD), and to determine if the differences could be explained by dentist-related variables ("social and demographic attributes," "job situation," and "attitudes"). MATERIALS AND METHODS: Questionnaires were sent to a random sample of 2,059 Swedish general dentists, with a response rate of 76%. In the questionnaire, the choice between FPDs and RPDs in a clinical situation was presented. The dentists were asked to mark on 14-item visual analogue scales the relative importance he or she gave the different items. The items were analyzed through principal components analysis, where a 3-factor solution was obtained; the factors were labeled as "time," "health," and "comfort." The factors were run as dependent variables in multiple regression analyses. RESULTS: Great individual variations were seen, but the differences between groups of dentists were small. The items evaluated as most important were "patient's wish," "condition of possible abutment teeth," and "prognosis for delivered treatment." Male dentists gave significantly greater importance to the "health" factor compared to female dentists. The attitudinal variable "patient information" showed significant associations with all 3 factors in the multivariate models. CONCLUSION: Great individual differences were seen regarding the importance of the various items. In multiple regression models, several independent variables showed significant associations, most interestingly the attitudinal variable "patient information." Low explanatory (R2) values indicate that it is necessary to capture more variables of importance for the prosthodontic decision-making process.

A multilevel analysis of factors affecting the longevity of fixed partial dentures, retainers and abutments.

There is a methodological problem in analysis of data belonging to different hierarchical levels, e.g. patient, arch, and tooth. A method for multilevel modelling (MLM) that resolves this problem is available. This method which is presented in this article, was used to reanalyse previously published long-term treatment results concerning the longevity of fixed partial dentures, retainers and abutments. The main results were consistent, indicating that no great faults were committed when using the conventional logistic regression method. There were, however, differences when calculating the combined risks for various situations. The conventional method was found to over- and underestimate probabilities of survival in different cases, compared to the MLM method. Especially when the most negative factors were combined, the conventional method had a tendency to underestimate the risk. For example, if an abutment had the combination 'endodontically treated'; 'FPD placed by 'another dentist''; 'distal abutment'; and 'marginal bone loss > 50%'; the probability of the tooth remaining after 18-23 years was only 20% according to the MLM method but 35% according to the conventional method. It was concluded that MLM is the method of choice for many situations in dental research where data belonging to different levels are to be analysed.

A method for communication analysis in prosthodontics.

Particularly in prosthodontics, in which the issues of esthetic preferences and possibilities are abundant, improved knowledge about dentist patient communication during clinical encounters is important. Because previous studies on communication used different methods and patient materials, the results are difficult to evaluate. There is, therefore, a need for methodologic development. One method that makes it possible to quantitatively describe different interaction behaviors during clinical encounters is the Roter Method of Interaction Process Analysis (RIAS). Since the method was developed in the USA for use in the medical context, a translation of the method into Swedish and a modification of the categories for use in prosthodontics were necessary. The revised manual was used to code 10 audio recordings of dentist patient encounters at a specialist clinic for prosthodontics. No major alterations of the RIAS manual were made during the translation and modification. The study shows that it is possible to distinguish patterns of communication in audio-recorded dentist patient encounters. The method also made the identification of different interaction profiles possible. These profiles distinguished well among the audio-recorded encounters. The coding procedures were tested for intra-rater reliability and found to be 97% for utterance classification and lambda = 0.76 for categorization definition. It was concluded that the revised RIAS method is applicable in communication studies in prosthodontics.